Merge remote-tracking branch 'upstream/main' into haryr/aug25-rebase

# Conflicts:
#	resources/profiles/Custom.json
#	src/libslic3r/Brim.cpp
#	src/libslic3r/GCode.cpp
#	src/libslic3r/GCode.hpp
#	src/libslic3r/Preset.cpp
#	src/slic3r/GUI/3DScene.cpp
#	src/slic3r/GUI/ConfigManipulation.cpp
#	src/slic3r/GUI/GLCanvas3D.cpp
#	src/slic3r/GUI/Plater.cpp

src/libslic3r/AABBMesh.cpp

@@ -54,12 +54,12 @@ public:
                             int &                        i,
                             Eigen::Matrix<double, 1, 3> &closest)
     {
-        size_t idx_unsigned = 0;
-        Vec3d  closest_vec3d(closest);
-        double dist =
+        size_t idx_unsigned { 0 };
+        Vec3d  closest_vec3d { Vec3d::Zero() };
+        const double dist {
             AABBTreeIndirect::squared_distance_to_indexed_triangle_set(
                 its.vertices, its.indices, m_tree, point, idx_unsigned,
-                closest_vec3d);
+                closest_vec3d) };
         i       = int(idx_unsigned);
         closest = closest_vec3d;
         return dist;
@@ -311,10 +311,9 @@ AABBMesh::hit_result IndexedMesh::filter_hits(
 
 
 double AABBMesh::squared_distance(const Vec3d &p, int& i, Vec3d& c) const {
-    double sqdst = 0;
-    Eigen::Matrix<double, 1, 3> pp = p;
-    Eigen::Matrix<double, 1, 3> cc;
-    sqdst = m_aabb->squared_distance(*m_tm, pp, i, cc);
+    const Eigen::Matrix<double, 1, 3> pp { p };
+    Eigen::Matrix<double, 1, 3> cc { Vec3d::Zero() };
+    const double sqdst { m_aabb->squared_distance(*m_tm, pp, i, cc) };
     c = cc;
     return sqdst;
 }

src/libslic3r/AABBTreeLines.hpp

@@ -31,8 +31,9 @@ namespace AABBTreeLines {
             inline VectorType closest_point_to_origin(size_t primitive_index, ScalarType& squared_distance) const
             {
                 Vec<LineType::Dim, typename LineType::Scalar> nearest_point;
+                Vec<LineType::Dim, typename LineType::Scalar> cast_origin = origin.template cast<typename LineType::Scalar>();
                 const LineType& line = lines[primitive_index];
-                squared_distance = line_alg::distance_to_squared(line, origin.template cast<typename LineType::Scalar>(), &nearest_point);
+                squared_distance = line_alg::distance_to_squared(line, cast_origin, &nearest_point);
                 return nearest_point.template cast<ScalarType>();
             }
         };

src/libslic3r/AppConfig.cpp

@@ -280,6 +280,9 @@ void AppConfig::set_defaults()
         set(SETTING_OPENGL_FPS_CAP, std::to_string(fps_cap));
     }
 
+    // The getter already defaults, parses and clamps; write back what it resolves to.
+    set(SETTING_PLUGIN_PAGES_VISIBLE_COUNT, std::to_string(get_plugin_pages_visible_count()));
+
     if (get(SETTING_OPENGL_SHOW_FPS_OVERLAY).empty())
         set_bool(SETTING_OPENGL_SHOW_FPS_OVERLAY, false);
 
@@ -626,6 +629,12 @@ void AppConfig::set_defaults()
         set_bool("window_buttons_on_left", false);
 #endif
 
+    if (get("use_printer_agents").empty())
+    {
+        // false = legacy behavior using print hosts
+        set_bool("use_printer_agents", false);
+    }
+
     // Remove legacy window positions/sizes
     erase("app", "main_frame_maximized");
     erase("app", "main_frame_pos");
@@ -847,6 +856,10 @@ std::string AppConfig::load()
                         local_machine.dev_ip = p["dev_ip"].get<std::string>();
                     if (p.contains("printer_type"))
                         local_machine.printer_type = p["printer_type"].get<std::string>();
+                    if (p.contains("printer_agent_id"))
+                        local_machine.printer_agent_id = p["printer_agent_id"].get<std::string>();
+                    if (p.contains("access_code"))
+                        local_machine.access_code = p["access_code"].get<std::string>();
                     m_local_machines[local_machine.dev_id] = local_machine;
                 }
             } else {
@@ -877,7 +890,7 @@ std::string AppConfig::load()
                 }
             }
         }
-    } catch(std::exception err) {
+    } catch(const std::exception &err) {
         BOOST_LOG_TRIVIAL(info) << format("parse app config \"%1%\", error: %2%", AppConfig::loading_path(), err.what());
 
         return err.what();
@@ -1059,6 +1072,8 @@ void AppConfig::save()
         m_json["dev_name"]         = local_machine.second.dev_name;
         m_json["dev_ip"]           = local_machine.second.dev_ip;
         m_json["printer_type"]     = local_machine.second.printer_type;
+        m_json["printer_agent_id"] = local_machine.second.printer_agent_id;
+        m_json["access_code"]      = local_machine.second.access_code;
 
         j["local_machines"][local_machine.first] = m_json;
     }
@@ -1624,6 +1639,22 @@ void AppConfig::set_network_plugin_version(const std::string& version)
     set(SETTING_NETWORK_PLUGIN_VERSION, version);
 }
 
+int AppConfig::get_plugin_pages_visible_count() const
+{
+    std::string value = get(SETTING_PLUGIN_PAGES_VISIBLE_COUNT);
+    if (value.empty())
+        return PLUGIN_PAGES_VISIBLE_COUNT_DEFAULT;
+
+    int visible_count = PLUGIN_PAGES_VISIBLE_COUNT_DEFAULT;
+    try {
+        visible_count = std::stoi(value);
+    }
+    catch (...) {
+        return PLUGIN_PAGES_VISIBLE_COUNT_DEFAULT;
+    }
+    return std::clamp(visible_count, PLUGIN_PAGES_VISIBLE_COUNT_MIN, PLUGIN_PAGES_VISIBLE_COUNT_MAX);
+}
+
 std::vector<std::string> AppConfig::get_skipped_network_versions() const
 {
     std::vector<std::string> result;

src/libslic3r/AppConfig.hpp

@@ -41,6 +41,11 @@ using namespace nlohmann;
 #define SETTING_OPENGL_PHONG_SSAO "opengl_phong_ssao"
 #define SETTING_OPENGL_PHONG_SMOOTH_NORMALS "opengl_phong_smooth_normals"
 
+#define SETTING_PLUGIN_PAGES_VISIBLE_COUNT "plugin_pages_visible_count"
+#define PLUGIN_PAGES_VISIBLE_COUNT_MIN 1
+#define PLUGIN_PAGES_VISIBLE_COUNT_DEFAULT 5
+#define PLUGIN_PAGES_VISIBLE_COUNT_MAX 10
+
 #if defined(_WIN32) || defined(_WIN64)
 #define BAMBU_NETWORK_AGENT_VERSION_LEGACY "01.10.01.09"
 #else
@@ -61,10 +66,19 @@ struct BBLocalMachine
     std::string dev_ip;
     std::string dev_id; /* serial number */
     std::string printer_type; /* model_id */
+    std::string printer_agent_id; /* id of the IPrinterAgent that discovered/bound this device, e.g. "bbl"; empty for entries persisted before this field existed */
+    // Access code, scoped to printer_agent_id above - so a code saved while bound under one
+    // printer agent isn't treated as valid for a different, independent agent talking to the
+    // same physical dev_id. Empty for entries persisted before this field existed; those fall
+    // back to the legacy flat "access_code"/"user_access_code" AppConfig sections (BBL-only,
+    // since BBL was the only agent when they were saved) - see
+    // get_access_code_with_legacy_fallback() in DevManager.cpp.
+    std::string access_code;
 
     bool operator==(const BBLocalMachine& other) const
     {
-        return dev_name == other.dev_name && dev_ip == other.dev_ip && dev_id == other.dev_id && printer_type == other.printer_type;
+        return dev_name == other.dev_name && dev_ip == other.dev_ip && dev_id == other.dev_id && printer_type == other.printer_type &&
+               printer_agent_id == other.printer_agent_id && access_code == other.access_code;
     }
     bool operator!=(const BBLocalMachine& other) const { return !operator==(other); }
 };
@@ -374,6 +388,10 @@ public:
     std::string get_network_plugin_version() const;
     void set_network_plugin_version(const std::string& version);
 
+    // Number of plugin pages shown as fixed tabs before the rest are collapsed into a
+    // dropdown on the last tab.
+    int get_plugin_pages_visible_count() const;
+
     std::vector<std::string> get_skipped_network_versions() const;
     void add_skipped_network_version(const std::string& version);
     bool is_network_version_skipped(const std::string& version) const;

src/libslic3r/Arachne/WallToolPaths.cpp

@@ -154,8 +154,8 @@ void simplify(Polygon &thiss, const int64_t smallest_line_segment_squared, const
         //h^2 = L^2 / b^2     [factor the divisor]
         const int64_t height_2 = double(area_removed_so_far) * double(area_removed_so_far) / double(base_length_2);
         // Orca: The value of `height_2` is squared, so we need to compare it with the squared value
-        if ((height_2 <= Slic3r::sqr(scaled<coord_t>(0.005)) //Almost exactly colinear (barring rounding errors).
-             && Line::distance_to_infinite(current, previous, next) <= scaled<double>(0.005))) // make sure that height_2 is not small because of cancellation of positive and negative areas
+        if ((height_2 <= Slic3r::sqr(colinear_vertex_tolerance()) //Almost exactly colinear (barring rounding errors).
+             && Line::distance_to_infinite(current, previous, next) <= double(colinear_vertex_tolerance()))) // make sure that height_2 is not small because of cancellation of positive and negative areas
             continue;
 
         if (length2 < smallest_line_segment_squared

src/libslic3r/Arachne/WallToolPaths.hpp

@@ -23,14 +23,14 @@ inline coord_t    meshfix_maximum_extrusion_area_deviation() { return scaled<coo
 class WallToolPathsParams
 {
 public:
-    float   min_bead_width;
-    float   min_feature_size;
-    float   min_length_factor;
-    float   wall_transition_length;
-    float   wall_transition_angle;
-    float   wall_transition_filter_deviation;
-    int     wall_distribution_count;
-    bool    is_top_or_bottom_layer;
+    float   min_bead_width                   = 0.f;
+    float   min_feature_size                 = 0.f;
+    float   min_length_factor                = 0.5f;
+    float   wall_transition_length           = 0.f;
+    float   wall_transition_angle            = 10.f;
+    float   wall_transition_filter_deviation = 0.f;
+    int     wall_distribution_count          = 1;
+    bool    is_top_or_bottom_layer           = false;
 
     coord_t wall_maximum_resolution = meshfix_maximum_resolution();
     coord_t wall_maximum_deviation  = meshfix_maximum_deviation();

src/libslic3r/Arachne/utils/ExtrusionLine.cpp

@@ -133,8 +133,8 @@ void ExtrusionLine::simplify(const int64_t smallest_line_segment_squared, const
         const auto    height_2 = int64_t(double(area_removed_so_far) * double(area_removed_so_far) / double(base_length_2));
         const int64_t extrusion_area_error = calculateExtrusionAreaDeviationError(previous, current, next);
         // Orca: The value of `height_2` is squared, so we need to compare it with the squared value
-        if ((height_2 <= Slic3r::sqr(scaled<coord_t>(0.005)) // Almost exactly colinear (barring rounding errors).
-             && Line::distance_to_infinite(current.p, previous.p, next.p) <= scaled<double>(0.005)) // Make sure that height_2 is not small because of cancellation of positive and negative areas
+        if ((height_2 <= Slic3r::sqr(colinear_vertex_tolerance()) // Almost exactly colinear (barring rounding errors).
+             && Line::distance_to_infinite(current.p, previous.p, next.p) <= double(colinear_vertex_tolerance())) // Make sure that height_2 is not small because of cancellation of positive and negative areas
             // We shouldn't remove middle junctions of colinear segments if the area changed for the C-P segment is exceeding the maximum allowed
              && extrusion_area_error <= maximum_extrusion_area_deviation)
         {

src/libslic3r/Arachne/utils/ExtrusionLine.hpp

@@ -32,6 +32,14 @@ class Flow;
 namespace Slic3r::Arachne
 {
 
+// ORCA: Tolerance of the "almost exactly colinear" early-out shared by the two simplify() passes
+// (this file and WallToolPaths.cpp). That test drops a vertex regardless of the user's Maximum wall
+// resolution/deviation, so it has to stay at the scale of coordinate rounding noise. A larger value
+// silently decimates finely tessellated curves: on a circle, one vertex may be removed whenever the
+// sagitta of the resulting chord falls below the tolerance, which halves the point count and turns
+// smooth arcs into corners the firmware has to decelerate through.
+inline coord_t colinear_vertex_tolerance() { return coord_t(SCALED_EPSILON); }
+
 /*!
  * Represents a polyline (not just a line) that is to be extruded with variable
  * line width.

src/libslic3r/BoundingBox.cpp

@@ -8,6 +8,8 @@
 namespace Slic3r {
 
 template BoundingBoxBase<Point, Points>::BoundingBoxBase(const Points &points);
+template void BoundingBoxBase<Point, Points>::construct<0, BoundingBox, Points::const_iterator>(BoundingBox&, Points::const_iterator, Points::const_iterator);
+template void BoundingBoxBase<Point, Points>::construct<1, BoundingBox, Points::const_iterator>(BoundingBox&, Points::const_iterator, Points::const_iterator);
 template BoundingBoxBase<Vec2d>::BoundingBoxBase(const std::vector<Vec2d> &points);
 
 template BoundingBox3Base<Vec3d>::BoundingBox3Base(const std::vector<Vec3d> &points);

src/libslic3r/BoundingBox.hpp

@@ -25,7 +25,7 @@ public:
         min(p1), max(p1), defined(false) { merge(p2); merge(p3); }
 
     template<class It, class = IteratorOnly<It>>
-    BoundingBoxBase(It from, It to)
+    BoundingBoxBase(It from, It to) : BoundingBoxBase()
         { construct(*this, from, to); }
 
     BoundingBoxBase(const PointsType &points)

src/libslic3r/Brim.cpp

@@ -349,7 +349,7 @@ static ExPolygons make_brim_ears_auto(const ExPolygons& obj_expoly, coord_t size
     return mouse_ears_ex;
 }
 
-static ExPolygons make_brim_ears(const PrintObject* object, const double& flowWidth, float brim_offset, Flow &flow, bool is_outer_brim)
+static ExPolygons make_brim_ears(const PrintObject* object)
 {
     ExPolygons mouse_ears_ex;
     BrimPoints brim_ear_points = object->model_object()->brim_points;
@@ -373,12 +373,7 @@ static ExPolygons make_brim_ears(const PrintObject* object, const double& flowWi
         Vec3f world_pos = pt.transform(trsf.get_matrix());
         if ( world_pos.z() > 0) continue;
         Polygon point_round;
-        float brim_width = floor(scale_(pt.head_front_radius) / flowWidth / 2) * flowWidth * 2;
-        if (is_outer_brim) {
-            double flowWidthScale = flowWidth / SCALING_FACTOR;
-            brim_width = floor(brim_width / flowWidthScale / 2) * flowWidthScale * 2;
-        }
-        coord_t size_ear = (brim_width - brim_offset - flow.scaled_spacing());
+        const coord_t size_ear = scale_(pt.head_front_radius);
         for (size_t i = 0; i < POLY_SIDE_COUNT; i++) {
             double angle = (2.0 * PI * i) / POLY_SIDE_COUNT;
             point_round.points.emplace_back(size_ear * cos(angle), size_ear * sin(angle));
@@ -452,7 +447,8 @@ static ExPolygons outer_inner_brim_area(const Print& print,
             bool               has_brim_auto = object->config().brim_type == btAutoBrim;
             const bool         use_auto_brim_ears = object->config().brim_type == btEar;
             const bool         use_brim_ears = object->config().brim_type == btPainted;
-            const bool         has_inner_brim = brim_type == btInnerOnly || brim_type == btOuterAndInner || use_auto_brim_ears || use_brim_ears;
+            const bool         use_inner_brim_ears = (use_auto_brim_ears || use_brim_ears) && !object->config().brim_ears_outer_only.value;
+            const bool         has_inner_brim = brim_type == btInnerOnly || brim_type == btOuterAndInner || use_inner_brim_ears;
             // btLeadingEdgeOnly is a belt-printer mode; on a flat bed there is no leading
             // edge, so it degrades to an ordinary outer brim rather than silently to none.
             const bool         has_outer_brim = brim_type == btOuterOnly || brim_type == btOuterAndInner || brim_type == btAutoBrim || brim_type == btLeadingEdgeOnly || use_auto_brim_ears || use_brim_ears;
@@ -533,7 +529,7 @@ static ExPolygons outer_inner_brim_area(const Print& print,
                                 auto innerExpoly = offset_ex(ex_poly.contour, brim_offset, jtRound, SCALED_RESOLUTION);
                                 ExPolygons outerExpoly;
                                 if (use_brim_ears) {
-                                    outerExpoly = make_brim_ears(object, flowWidth, brim_offset, flow, true);
+                                    outerExpoly = make_brim_ears(object);
                                     //outerExpoly = offset_ex(outerExpoly, brim_width_mod, jtRound, SCALED_RESOLUTION);
                                 } else if (use_auto_brim_ears) {
                                     coord_t size_ear = (brim_width_mod - brim_offset - flow.scaled_spacing());
@@ -547,7 +543,7 @@ static ExPolygons outer_inner_brim_area(const Print& print,
                                 ExPolygons outerExpoly;
                                 auto innerExpoly = offset_ex(ex_poly_holes_reversed, -brim_width - brim_offset);
                                 if (use_brim_ears) {
-                                    outerExpoly = make_brim_ears(object, flowWidth, brim_offset, flow, false);
+                                    outerExpoly = make_brim_ears(object);
                                 } else if (use_auto_brim_ears) {
                                     coord_t size_ear = (brim_width - brim_offset - flow.scaled_spacing());
                                     outerExpoly = make_brim_ears_auto(offset_ex(ex_poly_holes_reversed, -brim_offset), size_ear, ear_detection_length, brim_ears_max_angle, false);

src/libslic3r/CMakeLists.txt

@@ -162,6 +162,8 @@ set(lisbslic3r_sources
     Fill/FillConcentric.hpp
     Fill/FillConcentricInternal.cpp
     Fill/FillConcentricInternal.hpp
+    Fill/FillCornerSmoothing.cpp
+    Fill/FillCornerSmoothing.hpp
     Fill/Fill.cpp
     Fill/FillCrossHatch.cpp
     Fill/FillCrossHatch.hpp
@@ -363,6 +365,8 @@ set(lisbslic3r_sources
     Polyline.hpp
     PresetBundle.cpp
     PresetBundle.hpp
+    PresetCacheFormat.cpp
+    PresetCacheFormat.hpp
     Preset.cpp
     Preset.hpp
     PrincipalComponents2D.cpp

src/libslic3r/Config.cpp

@@ -2031,7 +2031,8 @@ const double& DynamicConfig::opt_float(const t_config_option_key &opt_key, unsig
         return opt_floats_nullable->get_at(idx);
     } else {
         assert(false);
-        return 0;
+        static const double zero = 0.0;
+        return zero;
     }
 }
 

src/libslic3r/Config.hpp

@@ -28,6 +28,9 @@
 
 #include <cereal/access.hpp>
 #include <cereal/types/base_class.hpp>
+// The serialize() members below archive ConfigOption hierarchies through
+// cereal::base_class, whose registration machinery lives in polymorphic.hpp.
+#include <cereal/types/polymorphic.hpp>
 
 namespace Slic3r {
     struct FloatOrPercent
@@ -2273,6 +2276,8 @@ public:
         plugin_picker,
         // Raw JSON string value, edited through a dialog behind a button rather than in the row.
         plugin_config,
+        // PrinterAgentChoice
+        printer_agent_select,
     };
 
 	// Identifier of this option. It is stored here so that it is accessible through the by_serialization_key_ordinal map.
@@ -2980,6 +2985,8 @@ public:
     const double &      opt_float(const t_config_option_key &opt_key, unsigned int idx) const;
     double &            opt_float_nullable(const t_config_option_key &opt_key, unsigned int idx) { return this->option<ConfigOptionFloatsNullable>(opt_key)->get_at(idx); }
     const double &      opt_float_nullable(const t_config_option_key &opt_key, unsigned int idx) const { return dynamic_cast<const ConfigOptionFloatsNullable *>(this->option(opt_key))->get_at(idx); }
+    FloatOrPercent &    opt_float_or_percent_nullable(const t_config_option_key &opt_key, unsigned int idx) { return this->option<ConfigOptionFloatsOrPercentsNullable>(opt_key)->get_at(idx); }
+    const FloatOrPercent & opt_float_or_percent_nullable(const t_config_option_key &opt_key, unsigned int idx) const { return dynamic_cast<const ConfigOptionFloatsOrPercentsNullable *>(this->option(opt_key))->get_at(idx); }
 
     int&                opt_int(const t_config_option_key &opt_key)                             { return this->option<ConfigOptionInt>(opt_key)->value; }
     int                 opt_int(const t_config_option_key &opt_key) const                       { return dynamic_cast<const ConfigOptionInt*>(this->option(opt_key))->value; }

src/libslic3r/Extruder.cpp

@@ -220,12 +220,12 @@ double Extruder::retract_restart_extra() const
 
 double Extruder::retract_length_toolchange() const
 {
-    return m_config->retract_length_toolchange.get_at(extruder_id());
+    return m_config->retract_length_toolchange.get_at(m_config_index);
 }
 
 double Extruder::retract_restart_extra_toolchange() const
 {
-    return m_config->retract_restart_extra_toolchange.get_at(extruder_id());
+    return m_config->retract_restart_extra_toolchange.get_at(m_config_index);
 }
 
 double Extruder::travel_slope() const

src/libslic3r/Feature/FuzzySkin/FuzzySkin.cpp

@@ -682,7 +682,7 @@ Polygon apply_fuzzy_skin(const Polygon& polygon, const PerimeterGenerator& perim
     return fuzzified;
 }
 
-void apply_fuzzy_skin(Arachne::ExtrusionLine* extrusion, const PerimeterGenerator& perimeter_generator, const bool is_contour)
+void apply_fuzzy_skin(Arachne::ExtrusionLine* extrusion, const PerimeterGenerator& perimeter_generator, const bool is_contour, const bool closed)
 {
     const auto  slice_z = perimeter_generator.slice_z;
     const auto& regions = perimeter_generator.regions_by_fuzzify;
@@ -690,7 +690,7 @@ void apply_fuzzy_skin(Arachne::ExtrusionLine* extrusion, const PerimeterGenerato
         const auto& config  = regions.begin()->first;
         const bool  fuzzify = should_fuzzify(config, perimeter_generator.layer_id, extrusion->inset_idx, is_contour);
         if (fuzzify)
-            fuzzy_extrusion_line(extrusion->junctions, slice_z, config);
+            fuzzy_extrusion_line(extrusion->junctions, slice_z, config, closed);
     } else {
         // Merge regions that produce identical fuzzy effects (differ only in type).
         // When the style (e.g. External) and a painted region (All) both fuzzify this loop
@@ -701,10 +701,19 @@ void apply_fuzzy_skin(Arachne::ExtrusionLine* extrusion, const PerimeterGenerato
 
             // Fast path: single merged region — apply directly without splitting
             if (merged_regions.size() == 1 && merged_regions.front().expolygons.empty()) {
-                fuzzy_extrusion_line(extrusion->junctions, slice_z, *merged_regions.front().config);
+                fuzzy_extrusion_line(extrusion->junctions, slice_z, *merged_regions.front().config, closed);
                 return;
             }
 
+            // Open path means this is a thin wall that collapsed into a single thick line, in this case the path will go exactly
+            // between the middle two sides of the object. And since the paint segmentation never goes beyond the middle line because
+            // it uses voronoi diagram, we need to expand the segmentation a little bit to make sure it covers the path.
+            if (!closed) {
+                for (auto& r : merged_regions) {
+                    r.expolygons = offset_ex(r.expolygons, perimeter_generator.ext_perimeter_flow.scaled_width() / 10);
+                }
+            }
+
 #ifdef DEBUG_FUZZY
             {
                 int i = 0;
@@ -752,7 +761,7 @@ void apply_fuzzy_skin(Arachne::ExtrusionLine* extrusion, const PerimeterGenerato
                 // Fuzzy splitted extrusion
                 if (std::all_of(splitted.begin(), splitted.end(), [](const Algorithm::SplitLineJunction& j) { return j.clipped; })) {
                     // The entire polygon is fuzzified
-                    fuzzy_extrusion_line(extrusion->junctions, slice_z, *r.config);
+                    fuzzy_extrusion_line(extrusion->junctions, slice_z, *r.config, closed);
                     continue;
                 } else {
                     const auto                              current_ext = extrusion->junctions;
@@ -803,7 +812,7 @@ void apply_fuzzy_skin(Arachne::ExtrusionLine* extrusion, const PerimeterGenerato
                     }
 
                     //Orca: ensure the loop is closed after fuzzy
-                    if (!extrusion->junctions.empty() && extrusion->junctions.front().p != extrusion->junctions.back().p) {
+                    if (closed && !extrusion->junctions.empty() && extrusion->junctions.front().p != extrusion->junctions.back().p) {
                         extrusion->junctions.back().p = extrusion->junctions.front().p;
                         extrusion->junctions.back().w = extrusion->junctions.front().w;
                     }

src/libslic3r/Feature/FuzzySkin/FuzzySkin.hpp

@@ -16,7 +16,7 @@ void group_region_by_fuzzify(PerimeterGenerator& g);
 bool should_fuzzify(const FuzzySkinConfig& config, int layer_id, size_t loop_idx, bool is_contour);
 
 Polygon apply_fuzzy_skin(const Polygon& polygon, const PerimeterGenerator& perimeter_generator, size_t loop_idx, bool is_contour);
-void    apply_fuzzy_skin(Arachne::ExtrusionLine* extrusion, const PerimeterGenerator& perimeter_generator, bool is_contour);
+void    apply_fuzzy_skin(Arachne::ExtrusionLine* extrusion, const PerimeterGenerator& perimeter_generator, bool is_contour, bool closed = true);
 
 } // namespace Slic3r::Feature::FuzzySkin
 

src/libslic3r/FilamentGroup.cpp

@@ -1021,7 +1021,7 @@ namespace Slic3r
             if (FGMode::MatchMode == ctx.group_info.mode)
                 return calc_filament_group_for_match(cost);
         }
-        catch (const FilamentGroupException& e) {
+        catch (const FilamentGroupException&) {
         }
 
         return calc_filament_group_for_flush(cost);

src/libslic3r/Fill/Fill.cpp

@@ -278,6 +278,9 @@ struct SurfaceFillParams
     // For Gyroid: when true, use the parameterized "optimized" wave.
     bool gyroid_optimized = false;
 
+    // Orca: corner smoothing factor in the range [0, 1].
+    double      smooth_factor { 0. };
+
     CenterOfSurfacePattern center_of_surface_pattern{CenterOfSurfacePattern::Each_Surface};
     bool                   separated_infills{false};
 
@@ -316,6 +319,7 @@ struct SurfaceFillParams
 		RETURN_COMPARE_NON_EQUAL(skin_infill_depth);
         RETURN_COMPARE_NON_EQUAL(infill_overhang_angle);
 		RETURN_COMPARE_NON_EQUAL(gyroid_optimized);
+        RETURN_COMPARE_NON_EQUAL(smooth_factor);
         RETURN_COMPARE_NON_EQUAL(center_of_surface_pattern);
         RETURN_COMPARE_NON_EQUAL(separated_infills);
 		RETURN_COMPARE_NON_EQUAL_TYPED(unsigned, fill_order);
@@ -348,6 +352,7 @@ struct SurfaceFillParams
                 this->center_of_surface_pattern == rhs.center_of_surface_pattern &&
                 this->separated_infills       == rhs.separated_infills &&
                 this->gyroid_optimized        == rhs.gyroid_optimized        &&
+                this->smooth_factor           == rhs.smooth_factor           &&
                 this->fill_order              == rhs.fill_order;
 	}
 };
@@ -964,6 +969,11 @@ std::vector<SurfaceFill> group_fills(const Layer &layer, LockRegionParam &lock_p
                     params.angle = calculate_infill_rotation_angle(layer.object(), layer.id(), region_config.infill_direction.value,
                                                                    region_config.sparse_infill_rotate_template.value);
                     params.fixed_angle = !region_config.sparse_infill_rotate_template.value.empty();
+
+                    // Orca: the smoothing factor only applies to the sparse infill patterns that
+                    // implement it. The fills clamp and validate the value themselves.
+                    if (is_smoothable_infill_pattern(params.pattern, params.multiline))
+                        params.smooth_factor = 0.01 * region_config.sparse_infill_smooth_factor.value;
                 } else {
                     const bool top_layer_direction_set    = surface.is_top() && region_config.top_layer_direction.value >= 0.;
                     const bool bottom_layer_direction_set = surface.is_bottom() && region_config.bottom_layer_direction.value >= 0.;
@@ -1328,6 +1338,7 @@ void Layer::make_fills(FillAdaptive::Octree* adaptive_fill_octree, FillAdaptive:
         params.lateral_lattice_angle_2   = surface_fill.params.lateral_lattice_angle_2;
         params.infill_overhang_angle   = surface_fill.params.infill_overhang_angle;
         params.gyroid_optimized          = surface_fill.params.gyroid_optimized;
+        params.smooth_factor             = surface_fill.params.smooth_factor;
 
 		// BBS
 		params.flow = surface_fill.params.flow;
@@ -1569,6 +1580,7 @@ Polylines Layer::generate_sparse_infill_polylines_for_anchoring(FillAdaptive::Oc
         params.infill_overhang_angle   = surface_fill.params.infill_overhang_angle;
         params.multiline         = surface_fill.params.multiline;
         params.gyroid_optimized          = surface_fill.params.gyroid_optimized;
+        params.smooth_factor             = surface_fill.params.smooth_factor;
 
         for (ExPolygon &expoly : surface_fill.expolygons) {
             // Spacing is modified by the filler to indicate adjustments. Reset it for each expolygon.

src/libslic3r/Fill/Fill3DHoneycomb.cpp

@@ -2,6 +2,7 @@
 #include "../ShortestPath.hpp"
 #include "../Surface.hpp"
 #include "FillBase.hpp"
+#include "FillCornerSmoothing.hpp"
 #include "Fill3DHoneycomb.hpp"
 
 namespace Slic3r {
@@ -271,6 +272,9 @@ void Fill3DHoneycomb::_fill_surface_single(
     for (Polyline &pl : polylines){
       pl.translate(bb.min);
       pl.simplify(5 * spacing); // simplify to 5x line width
+      // Orca: round the corners of the octahedral wave. The layers where the wave degenerates to a
+      // straight line have no corner to round.
+      smooth_polyline_corners(pl, params.smooth_factor, scaled<double>(params.resolution));
     }
 
     // Apply multiline offset if needed

src/libslic3r/Fill/FillBase.cpp

@@ -1857,12 +1857,12 @@ static inline void base_support_extend_infill_lines(Polylines &infill, BoundaryI
         const bool                   first           = graph.first(cp);
         int                          extend_next_idx = -1;
         int                          extend_prev_idx = -1;
-        coord_t                      dist_y_prev;
-        coord_t                      dist_y_next;
-        double                       arc_len_prev;
-        double                       arc_len_next;
+        coord_t                      dist_y_prev     = 0;
+        coord_t                      dist_y_next     = 0;
+        double                       arc_len_prev    = 0;
+        double                       arc_len_next    = 0;
 
-        if (! graph.next_vertical(cp)){
+        if (! graph.next_vertical(cp)) {
             size_t i = cp.point_idx;
             size_t j = next_idx_modulo(i, contour);
             while (j != cp.next_on_contour->point_idx) {

src/libslic3r/Fill/FillBase.hpp

@@ -82,6 +82,9 @@ struct FillParams
     // For Gyroid: when true, use the parameterized "optimized" variant.
     bool        gyroid_optimized { false };
 
+    // Orca: corner smoothing factor in the range [0, 1].
+    double      smooth_factor { 0. };
+
     // For Lateral lattice
     coordf_t    lateral_lattice_angle_1    { 0.f };
     coordf_t    lateral_lattice_angle_2    { 0.f };

src/libslic3r/Fill/FillConcentric.cpp

@@ -5,6 +5,7 @@
 #include "Arachne/WallToolPaths.hpp"
 
 #include "FillConcentric.hpp"
+#include "FillCornerSmoothing.hpp"
 #include <libslic3r/ShortestPath.hpp>
 
 namespace Slic3r {
@@ -32,12 +33,32 @@ void FillConcentric::_fill_surface_single(
 
     Polygons loops = to_polygons(contracted);
 
-    ExPolygons last { std::move(contracted) };
+    ExPolygons last { contracted };
     while (! last.empty()) {
         last = offset2_ex(last, -(distance + min_spacing/2), +min_spacing/2);
         append(loops, to_polygons(last));
     }
 
+    // Orca: round the corners of the loops. Unlike the other patterns these are never clipped to the
+    // fill region - they are its offsets - so a corner may only be rounded where the curve replacing it
+    // stays inside. Rounding cuts toward the inside of the turn, which around a hole, at a concave
+    // feature or across a thin region is outside the fill and would put the extrusion over a wall.
+    // The reach is capped at half the distance between two loops as well: a loop is as long as the
+    // object, and a corner cut by half of its side would swallow the neighbouring loops.
+    auto corner_stays_inside = [&contracted](const Vec2d &from, const Vec2d &to) {
+        // The straight chord between the ends of the curve is the deepest the curve can cut.
+        for (const double t : { 0.25, 0.5, 0.75 }) {
+            const Vec2d  sample = from + t * (to - from);
+            const Point  point(coord_t(sample.x()), coord_t(sample.y()));
+            if (std::none_of(contracted.begin(), contracted.end(),
+                             [&point](const ExPolygon &region) { return region.contains(point); }))
+                return false;
+        }
+        return true;
+    };
+    smooth_polygons_corners(loops, params.smooth_factor, scaled<double>(params.resolution), 0.5 * distance,
+                            corner_stays_inside);
+
     // generate paths from the outermost to the innermost, to avoid
     // adhesion problems of the first central tiny loops
     loops = union_pt_chained_outside_in(loops);

src/libslic3r/Fill/FillCornerSmoothing.cpp

@@ -0,0 +1,226 @@
+#include <array>
+
+#include "FillCornerSmoothing.hpp"
+
+namespace Slic3r {
+
+// Turns sharper than this are left untouched: both ends of the curve replacing such a corner nearly
+// coincide, so the corner would be rounded into a degenerate loop instead of a hairpin.
+static constexpr const double min_smoothed_turn_cosine = -0.9;
+
+// The control points are expressed in the (incoming, outgoing) basis of the corner, which is not
+// orthonormal for turns other than a right angle.
+using QuinticBezier = std::array<Vec2d, 6>;
+
+static bool is_bezier_flat(const QuinticBezier &curve, const Vec2d &incoming, const Vec2d &outgoing, const double deviation)
+{
+    // A Bezier curve stays inside the convex hull of its control points. Therefore, keeping every
+    // control point within a deviation-wide strip around the endpoint chord conservatively bounds the
+    // flattening error. The cross product is the perpendicular distance scaled by the chord length;
+    // comparing squared values avoids a square root.
+    auto         in_plane        = [&incoming, &outgoing](const Vec2d &c) { return c.x() * incoming + c.y() * outgoing; };
+    const Vec2d  chord           = in_plane(curve.back() - curve.front());
+    const double chord_length_sq = chord.squaredNorm();
+    const double max_cross_sq    = deviation * deviation * chord_length_sq;
+
+    for (size_t i = 1; i + 1 < curve.size(); ++i) {
+        const Vec2d  offset = in_plane(curve[i] - curve.front());
+        const double cross  = chord.x() * offset.y() - chord.y() * offset.x();
+        if (cross * cross > max_cross_sq)
+            return false;
+    }
+    return true;
+}
+
+static void subdivide_bezier(const QuinticBezier &curve, QuinticBezier &left, QuinticBezier &right)
+{
+    // Split the curve at t = 0.5 using de Casteljau's algorithm. Each averaging level contributes one
+    // control point to the left half and one to the right half; the latter is filled backwards to keep
+    // both resulting control polygons in their original parameter direction.
+    QuinticBezier subdivision = curve;
+    left.front() = subdivision.front();
+    right.back() = subdivision.back();
+    for (size_t level = 1; level < curve.size(); ++level) {
+        for (size_t i = 0; i + level < curve.size(); ++i)
+            subdivision[i] = 0.5 * (subdivision[i] + subdivision[i + 1]);
+        left[level] = subdivision.front();
+        right[curve.size() - level - 1] = subdivision[curve.size() - level - 1];
+    }
+}
+
+static void flatten_bezier(
+    const QuinticBezier &curve, const Vec2d &incoming, const Vec2d &outgoing, const double deviation, std::vector<Vec2d> &output)
+{
+    // Subdivide to at least depth 1 so a rounded corner cannot collapse to a single diagonal chord.
+    // A uniform subdivision depth keeps samples at equal parameter intervals t = k / 2^depth,
+    // avoiding abrupt segment-length jumps at adaptive-depth boundaries.
+    static constexpr size_t max_depth = 16;
+
+    std::vector<QuinticBezier> subcurves(2);
+    subdivide_bezier(curve, subcurves[0], subcurves[1]);
+
+    for (size_t depth = 1; depth < max_depth; ++depth) {
+        bool all_flat = true;
+        for (const QuinticBezier &c : subcurves)
+            if (!is_bezier_flat(c, incoming, outgoing, deviation)) {
+                all_flat = false;
+                break;
+            }
+        if (all_flat)
+            break;
+        std::vector<QuinticBezier> finer(subcurves.size() * 2);
+        for (size_t i = 0; i < subcurves.size(); ++i)
+            subdivide_bezier(subcurves[i], finer[i * 2], finer[i * 2 + 1]);
+        subcurves = std::move(finer);
+    }
+
+    // The curve start is deliberately omitted so it can be shared with the straight leg feeding into it.
+    output.clear();
+    output.reserve(subcurves.size());
+    for (const QuinticBezier &c : subcurves)
+        output.emplace_back(c.back());
+}
+
+const std::vector<Vec2d>& CornerSmoother::curve_coefficients(
+    const double corner_distance, const Vec2d &incoming, const Vec2d &outgoing)
+{
+    const double cosine = incoming.dot(outgoing);
+    // Corners of the same size and turn angle are congruent, so they flatten identically. An infill
+    // path walks over the very same corner over and over again, the Hilbert curve over a single one.
+    if (m_has_cached_coefficients && corner_distance == m_cached_distance && cosine == m_cached_cosine)
+        return m_cached_coefficients;
+
+    // One canonical corner running from -corner_distance along the incoming leg to corner_distance
+    // along the outgoing one. At each end, the first three control points are collinear and equally
+    // spaced: the tangent follows the adjoining straight leg and the second derivative is zero. The
+    // endpoint curvature is therefore zero, giving G2 joins to both legs.
+    const double        d = corner_distance;
+    const QuinticBezier corner_curve {{
+        {-d, 0.}, {-0.7 * d, 0.}, {-0.4 * d, 0.}, {0., 0.4 * d}, {0., 0.7 * d}, {0., d}
+    }};
+    // Retain a finite positive tolerance if the smoother was set up with an invalid one.
+    const double deviation = m_tolerance > 0. && std::isfinite(m_tolerance) ? m_tolerance : EPSILON;
+    flatten_bezier(corner_curve, incoming, outgoing, deviation, m_cached_coefficients);
+
+    m_cached_distance         = corner_distance;
+    m_cached_cosine           = cosine;
+    m_has_cached_coefficients = true;
+    return m_cached_coefficients;
+}
+
+void CornerSmoother::round_corner(const Vec2d &previous, const Vec2d &corner, const Vec2d &next)
+{
+    m_corner_points.clear();
+
+    const Vec2d  incoming_leg = corner - previous;
+    const Vec2d  outgoing_leg = next - corner;
+    const double incoming_length = incoming_leg.norm();
+    const double outgoing_length = outgoing_leg.norm();
+    if (incoming_length < EPSILON || outgoing_length < EPSILON) {
+        m_corner_points.emplace_back(corner);
+        return;
+    }
+
+    const Vec2d  incoming = incoming_leg / incoming_length;
+    const Vec2d  outgoing = outgoing_leg / outgoing_length;
+    const double cross    = incoming.x() * outgoing.y() - incoming.y() * outgoing.x();
+    // A collinear vertex is no corner at all, and a hairpin cannot be rounded, see above.
+    if (std::abs(cross) < EPSILON || incoming.dot(outgoing) < min_smoothed_turn_cosine) {
+        m_corner_points.emplace_back(corner);
+        return;
+    }
+
+    // Consuming at most half of the shorter leg keeps the curves of two adjacent corners apart.
+    double corner_distance = m_corner_distance_ratio * std::min(incoming_length, outgoing_length);
+    if (m_max_corner_distance > 0.)
+        corner_distance = std::min(corner_distance, m_max_corner_distance);
+
+    const Vec2d curve_start = corner - corner_distance * incoming;
+    const Vec2d curve_end   = corner + corner_distance * outgoing;
+    if (m_corner_filter && !m_corner_filter(curve_start, curve_end)) {
+        m_corner_points.emplace_back(corner);
+        return;
+    }
+
+    const std::vector<Vec2d> &coefficients = curve_coefficients(corner_distance, incoming, outgoing);
+    m_corner_points.reserve(coefficients.size() + 1);
+    m_corner_points.emplace_back(curve_start);
+    for (const Vec2d &coefficient : coefficients)
+        m_corner_points.emplace_back(corner + coefficient.x() * incoming + coefficient.y() * outgoing);
+}
+
+// Rounds the corners of a scaled point sequence. A polygon closes implicitly, so all of its vertices
+// are corners; a polyline is an open path that keeps both of its ends, even where they coincide - a
+// path returning to where it started retraces its way back and is not a loop.
+static Points smooth_corners(const Points &points, const bool polygon, CornerSmoother &smoother)
+{
+    // A polygon has no free ends, so its first vertex is a corner like any other. Rounding it takes
+    // feeding the smoother the last vertex first, whose own output point is then dropped again.
+    size_t skip = polygon ? 1 : 0;
+
+    Points smoothed;
+    smoothed.reserve(2 * points.size());
+    auto emit = [&smoothed, &skip](const Vec2d &point) {
+        if (skip > 0) {
+            --skip;
+            return;
+        }
+        smoothed.emplace_back(coord_t(std::floor(point.x() + 0.5)), coord_t(std::floor(point.y() + 0.5)));
+    };
+
+    if (polygon)
+        smoother.push(points.back().cast<double>(), emit);
+    for (const Point &point : points)
+        smoother.push(point.cast<double>(), emit);
+    if (polygon)
+        // Wrap the first vertex around, so that the last one is a corner as well.
+        smoother.push(points.front().cast<double>(), emit);
+    smoother.flush(emit);
+
+    if (polygon)
+        // The flushed point is the wrapped first vertex, which a polygon does not store.
+        smoothed.pop_back();
+    return smoothed;
+}
+
+void smooth_polyline_corners(Polyline &polyline, const double smooth_factor, const double tolerance,
+                             const double max_corner_distance, const CornerFilter &corner_filter)
+{
+    CornerSmoother smoother(smooth_factor, tolerance, max_corner_distance, corner_filter);
+    if (!smoother.enabled() || polyline.size() < 3)
+        return;
+
+    polyline.points = smooth_corners(polyline.points, false, smoother);
+    // Rounding back to the integer grid may collapse neighbouring samples of a curve.
+    polyline.remove_duplicate_points();
+}
+
+void smooth_polylines_corners(Polylines &polylines, const double smooth_factor, const double tolerance,
+                              const double max_corner_distance, const CornerFilter &corner_filter)
+{
+    if (sanitize_smooth_factor(smooth_factor) == 0.)
+        return;
+    for (Polyline &polyline : polylines)
+        smooth_polyline_corners(polyline, smooth_factor, tolerance, max_corner_distance, corner_filter);
+}
+
+void smooth_polygons_corners(Polygons &polygons, const double smooth_factor, const double tolerance,
+                             const double max_corner_distance, const CornerFilter &corner_filter)
+{
+    CornerSmoother smoother(smooth_factor, tolerance, max_corner_distance, corner_filter);
+    if (!smoother.enabled())
+        return;
+
+    for (Polygon &polygon : polygons) {
+        if (polygon.size() < 3)
+            continue;
+        polygon.points = smooth_corners(polygon.points, true, smoother);
+        polygon.remove_duplicate_points();
+        // The curves of the first and of the last corner may have met on the segment they share. A
+        // polygon closes implicitly, so it must not repeat its first vertex at the end.
+        if (polygon.points.size() > 1 && polygon.points.front() == polygon.points.back())
+            polygon.points.pop_back();
+    }
+}
+
+} // namespace Slic3r

src/libslic3r/Fill/FillCornerSmoothing.hpp

@@ -0,0 +1,108 @@
+#pragma once
+
+#include <algorithm>
+#include <cmath>
+#include <functional>
+#include <vector>
+
+#include "../libslic3r.h"
+#include "../Point.hpp"
+#include "../Polygon.hpp"
+#include "../Polyline.hpp"
+
+namespace Slic3r {
+
+// Orca: NaN or infinite factors disable the smoothing, everything else is clamped to <0, 1>.
+inline double sanitize_smooth_factor(double smooth_factor)
+{
+    return std::isfinite(smooth_factor) ? std::clamp(smooth_factor, 0., 1.) : 0.;
+}
+
+// Decides whether a corner may be replaced by the curve that leaves the path at `from` and rejoins it
+// at `to`, both in the coordinate system of the pushed points. Rounding cuts toward the inside of the
+// turn, so a path that is not clipped to the fill region afterwards needs this to stay inside it.
+using CornerFilter = std::function<bool(const Vec2d &from, const Vec2d &to)>;
+
+// Orca: Replaces the sharp vertices of an infill path with curves that join the adjoining straight
+// legs with a continuous curvature, so the toolhead does not have to stop in every corner.
+// Points are pushed one by one, because the plane path fills produce their path on the fly, and
+// every point of the smoothed path is handed over to the caller supplied emit callback.
+// Fully smoothed adjacent corners meet at the midpoint of the segment they share, so the emitted
+// points may collapse onto each other once rounded to the integer grid of the caller. Dropping such
+// duplicates is left to the caller, which is the only one knowing that grid.
+class CornerSmoother
+{
+public:
+    // tolerance is the maximum chordal deviation of the flattened curves, in the units of the pushed
+    // points. max_corner_distance caps how far a curve may reach along a leg, in the same units; it
+    // bounds how far a rounded corner moves away from the original path, which matters where the legs
+    // are much longer than the spacing of the pattern. Zero leaves the reach uncapped.
+    CornerSmoother(double smooth_factor, double tolerance, double max_corner_distance = 0.,
+                   CornerFilter corner_filter = {})
+        : m_corner_distance_ratio(0.5 * sanitize_smooth_factor(smooth_factor)), m_tolerance(tolerance),
+          m_max_corner_distance(max_corner_distance), m_corner_filter(std::move(corner_filter))
+    {}
+
+    bool enabled() const { return m_corner_distance_ratio > 0.; }
+
+    template<typename Emit> void push(const Vec2d &point, Emit &emit)
+    {
+        if (m_pending == 0) {
+            emit(point);
+            m_previous = point;
+        } else if (m_pending > 1) {
+            round_corner(m_previous, m_corner, point);
+            for (const Vec2d &corner_point : m_corner_points)
+                emit(corner_point);
+            m_previous = m_corner;
+        }
+        m_corner  = point;
+        m_pending = std::min(m_pending + 1, 2);
+    }
+
+    // Emits the last point of the path and prepares the smoother for a new one.
+    template<typename Emit> void flush(Emit &emit)
+    {
+        if (m_pending > 1)
+            emit(m_corner);
+        m_pending = 0;
+    }
+
+private:
+    // Fills m_corner_points with the points replacing the corner vertex.
+    void round_corner(const Vec2d &previous, const Vec2d &corner, const Vec2d &next);
+    // Flattens the canonical corner curve of the given size and turn into coordinates of the
+    // (incoming, outgoing) basis of the corner. Cached, as an infill path repeats the same corner.
+    const std::vector<Vec2d>& curve_coefficients(double corner_distance, const Vec2d &incoming, const Vec2d &outgoing);
+
+    // Fraction of the shorter adjoining segment consumed on each side of a corner. Half of a segment
+    // is the maximum, otherwise the curves of two adjacent corners would overlap.
+    const double       m_corner_distance_ratio;
+    const double       m_tolerance;
+    const double       m_max_corner_distance;
+    const CornerFilter m_corner_filter;
+    std::vector<Vec2d> m_corner_points;
+    // Cached flattening of the last corner, valid for corners of the same size and turn angle.
+    std::vector<Vec2d> m_cached_coefficients;
+    double             m_cached_distance { 0. };
+    double             m_cached_cosine { 0. };
+    bool               m_has_cached_coefficients { false };
+
+    Vec2d m_previous { Vec2d::Zero() };
+    Vec2d m_corner { Vec2d::Zero() };
+    // Number of points held back: none, the first point of a path, or a corner candidate.
+    int   m_pending { 0 };
+};
+
+// Rounds the corners of already scaled paths in place. Paths of less than three points are left alone.
+// Both ends of a polyline are kept where they are, even when they coincide: such a path retraces its
+// way back and joining its ends would turn it into a loop. See CornerSmoother for max_corner_distance.
+void smooth_polyline_corners(Polyline &polyline, double smooth_factor, double tolerance,
+                             double max_corner_distance = 0., const CornerFilter &corner_filter = {});
+void smooth_polylines_corners(Polylines &polylines, double smooth_factor, double tolerance,
+                              double max_corner_distance = 0., const CornerFilter &corner_filter = {});
+// Polygons close implicitly, so every one of their vertices is a corner.
+void smooth_polygons_corners(Polygons &polygons, double smooth_factor, double tolerance,
+                             double max_corner_distance = 0., const CornerFilter &corner_filter = {});
+
+} // namespace Slic3r

src/libslic3r/Fill/FillCrossHatch.cpp

@@ -3,6 +3,7 @@
 #include "../Surface.hpp"
 #include <cmath>
 #include "FillBase.hpp"
+#include "FillCornerSmoothing.hpp"
 #include "FillCrossHatch.hpp"
 
 namespace Slic3r {
@@ -205,6 +206,9 @@ void FillCrossHatch ::_fill_surface_single(
     // shift the pattern to the actual space
     for (Polyline &pl : polylines) { pl.translate(bb.min); }
 
+    // Orca: round the corners of the transition layers. The repeat layers are straight lines and stay as they are.
+    smooth_polylines_corners(polylines, params.smooth_factor, scaled<double>(params.resolution));
+
     // Apply multiline offset if needed
     multiline_fill(polylines, params, spacing);
 

src/libslic3r/Fill/FillHoneycomb.cpp

@@ -2,6 +2,7 @@
 #include "../ShortestPath.hpp"
 #include "../Surface.hpp"
 
+#include "FillCornerSmoothing.hpp"
 #include "FillHoneycomb.hpp"
 
 namespace Slic3r {
@@ -70,6 +71,9 @@ void FillHoneycomb::_fill_surface_single(
             }
             p.rotate(-direction.first, m.hex_center);
             p.simplify(5 * spacing); // simplify to 5x line width
+            // Orca: round the corners of the honeycomb cells. Done before the clipping, so that the
+            // curves are cut by the region boundary just like the sharp path would be.
+            smooth_polyline_corners(p, params.smooth_factor, scaled<double>(params.resolution));
             all_polylines.push_back(p);
         }
     }

src/libslic3r/Fill/FillLightning.cpp

@@ -2,6 +2,7 @@
 #include "../Print.hpp"
 #include "../ShortestPath.hpp"
 #include "FillBase.hpp"
+#include "FillCornerSmoothing.hpp"
 #include "FillLightning.hpp"
 #include "Lightning/Generator.hpp"
 
@@ -17,6 +18,19 @@ void Filler::_fill_surface_single(
     const Layer &layer      = generator->getTreesForLayer(this->layer_id);
     Polylines    fill_lines = layer.convertToLines(to_polygons(expolygon), scaled<coord_t>(0.5 * this->spacing - this->overlap));
 
+    // Orca: round the turns of the branches. Hairpins are left sharp, as they cannot be rounded, and
+    // the reach is capped: cutting a corner moves the branch, and a branch is as long as the object
+    // rather than as long as one cell of a pattern, so half of a leg would merge it with its neighbour
+    // instead of rounding the turn between them. Half the distance between two branches keeps them
+    // apart. With more than one line per infill wall the branches are printed as outlines drawn around
+    // them, and the outlines of branches that run into each other merge into a single one; moving a
+    // branch by more than a fraction of its printed width breaks such an outline up into separate
+    // loops, so that width bounds the reach as well.
+    const double branch_width   = scaled<double>(this->spacing) * params.multiline;
+    const double branch_spacing = branch_width / std::max(double(params.density), EPSILON);
+    const double max_reach      = 0.5 * (params.multiline > 1 ? branch_width : branch_spacing);
+    smooth_polylines_corners(fill_lines, params.smooth_factor, scaled<double>(params.resolution), max_reach);
+
     // Apply multiline offset if needed
     multiline_fill(fill_lines, params, spacing);
 

src/libslic3r/Fill/FillPlanePath.cpp

@@ -2,6 +2,7 @@
 #include "../ShortestPath.hpp"
 #include "../Surface.hpp"
 
+#include "FillCornerSmoothing.hpp"
 #include "FillPlanePath.hpp"
 
 namespace Slic3r {
@@ -114,12 +115,12 @@ void FillPlanePath::_fill_surface_single(
             // Filling in a bounding box over the whole object, clip generated polyline against the snug bounding box.
             snug_bounding_box.translate(-shift.x(), -shift.y());
             InfillPolylineClipper output(snug_bounding_box, distance_between_lines);
-            this->generate(min_x, min_y, max_x, max_y, resolution, output);
+            this->generate(min_x, min_y, max_x, max_y, resolution, params, output);
             polyline.points = std::move(output.result());
         } else {
             // Filling in a snug bounding box, no need to clip.
             InfillPolylineOutput output(distance_between_lines);
-            this->generate(min_x, min_y, max_x, max_y, resolution, output);
+            this->generate(min_x, min_y, max_x, max_y, resolution, params, output);
             polyline.points = std::move(output.result());
         }
     }
@@ -288,6 +289,62 @@ static void generate_hilbert_curve(coord_t min_x, coord_t min_y, coord_t max_x,
     }
 }
 
+// Rounds the corners of the generated path on its way to the infill output.
+template<typename Output>
+class SmoothingPolylineOutput
+{
+public:
+    SmoothingPolylineOutput(Output &output, const double smooth_factor, const double tolerance)
+        : m_output(output), m_smoother(smooth_factor, tolerance) {}
+
+    void reserve(size_t n) { m_output.reserve(n); }
+    void add_point(const Vec2d &pt) { auto emit = emitter(); m_smoother.push(pt, emit); }
+    // The smoother holds back the last point of the path until it knows there is no corner left to round.
+    void finish() { auto emit = emitter(); m_smoother.flush(emit); }
+
+private:
+    // The curves of two adjacent corners meet at the midpoint of the segment they share, where they
+    // may round to the very same output point. Drop those, they would be zero length extrusions.
+    auto emitter()
+    {
+        return [this](const Vec2d &pt) {
+            const Point snapped = m_output.scaled(pt);
+            if (m_has_last_snapped && snapped == m_last_snapped)
+                return;
+            m_last_snapped     = snapped;
+            m_has_last_snapped = true;
+            m_output.add_point(pt);
+        };
+    }
+
+    Output        &m_output;
+    CornerSmoother m_smoother;
+    Point          m_last_snapped { Point::Zero() };
+    bool           m_has_last_snapped { false };
+};
+
+// Runs the path generator against the concrete output type, optionally through the corner smoother.
+// The outputs do not share a virtual add_point(), so the type has to be resolved here.
+template<typename GenerateFn>
+static void generate_path(InfillPolylineOutput &output, const FillParams &params, const double resolution, GenerateFn generate)
+{
+    const double smooth_factor = sanitize_smooth_factor(params.smooth_factor);
+    auto run = [smooth_factor, resolution, &generate](auto &out) {
+        if (smooth_factor == 0.) {
+            generate(out);
+        } else {
+            SmoothingPolylineOutput<std::remove_reference_t<decltype(out)>> smoothing(out, smooth_factor, resolution);
+            generate(smoothing);
+            smoothing.finish();
+        }
+    };
+
+    if (output.clips())
+        run(static_cast<InfillPolylineClipper&>(output));
+    else
+        run(output);
+}
+
 void FillHilbertCurve::generate(coord_t min_x, coord_t min_y, coord_t max_x, coord_t max_y, const double /* resolution */, InfillPolylineOutput &output)
 {
     if (output.clips())
@@ -296,6 +353,13 @@ void FillHilbertCurve::generate(coord_t min_x, coord_t min_y, coord_t max_x, coo
         generate_hilbert_curve(min_x, min_y, max_x, max_y, output);
 }
 
+void FillHilbertCurve::generate(coord_t min_x, coord_t min_y, coord_t max_x, coord_t max_y, const double resolution,
+    const FillParams &params, InfillPolylineOutput &output)
+{
+    generate_path(output, params, resolution,
+        [min_x, min_y, max_x, max_y](auto &out) { generate_hilbert_curve(min_x, min_y, max_x, max_y, out); });
+}
+
 template<typename Output>
 static void generate_octagram_spiral(coord_t min_x, coord_t min_y, coord_t max_x, coord_t max_y, Output &output)
 {
@@ -336,4 +400,11 @@ void FillOctagramSpiral::generate(coord_t min_x, coord_t min_y, coord_t max_x, c
         generate_octagram_spiral(min_x, min_y, max_x, max_y, output);
 }
 
+void FillOctagramSpiral::generate(coord_t min_x, coord_t min_y, coord_t max_x, coord_t max_y, const double resolution,
+    const FillParams &params, InfillPolylineOutput &output)
+{
+    generate_path(output, params, resolution,
+        [min_x, min_y, max_x, max_y](auto &out) { generate_octagram_spiral(min_x, min_y, max_x, max_y, out); });
+}
+
 } // namespace Slic3r

src/libslic3r/Fill/FillPlanePath.hpp

@@ -21,10 +21,10 @@ public:
     void            add_point(const Vec2d& pt) { m_out.emplace_back(this->scaled(pt)); }
     Points&& result() { return std::move(m_out); }
     virtual bool    clips() const { return false; }
-
-protected:
+    // The output grid the generated points are snapped to.
     const Point     scaled(const Vec2d& fpt) const { return { coord_t(floor(fpt.x() * m_scale_out + 0.5)), coord_t(floor(fpt.y() * m_scale_out + 0.5)) }; }
 
+protected:
     // Output polyline.
     Points          m_out;
 
@@ -53,6 +53,11 @@ protected:
     friend class InfillPolylineClipper;
     
     virtual void generate(coord_t min_x, coord_t min_y, coord_t max_x, coord_t max_y, const double resolution, InfillPolylineOutput &output) = 0;
+    virtual void generate(coord_t min_x, coord_t min_y, coord_t max_x, coord_t max_y, const double resolution,
+                                      const FillParams & /* params */, InfillPolylineOutput &output)
+    {
+        this->generate(min_x, min_y, max_x, max_y, resolution, output);
+    }
 };
 
 class FillArchimedeanChords : public FillPlanePath
@@ -75,6 +80,8 @@ public:
 protected:
     bool centered() const override { return false; }
     void generate(coord_t min_x, coord_t min_y, coord_t max_x, coord_t max_y, const double resolution, InfillPolylineOutput &output) override;
+    void generate(coord_t min_x, coord_t min_y, coord_t max_x, coord_t max_y, const double resolution,
+                              const FillParams &params, InfillPolylineOutput &output) override;
 };
 
 class FillOctagramSpiral : public FillPlanePath
@@ -86,6 +93,8 @@ public:
 protected:
     bool centered() const override { return true; }
     void generate(coord_t min_x, coord_t min_y, coord_t max_x, coord_t max_y, const double resolution, InfillPolylineOutput &output) override;
+    void generate(coord_t min_x, coord_t min_y, coord_t max_x, coord_t max_y, const double resolution,
+                              const FillParams &params, InfillPolylineOutput &output) override;
 };
 
 } // namespace Slic3r

src/libslic3r/Fill/FillRectilinear.cpp

@@ -18,6 +18,7 @@
 #include "../ShortestPath.hpp"
 #include "../VariableWidth.hpp"
 
+#include "FillCornerSmoothing.hpp"
 #include "FillRectilinear.hpp"
 
 // #define SLIC3R_DEBUG
@@ -3364,6 +3365,10 @@ bool FillRectilinear::fill_surface_trapezoidal(
         for (Polyline &pl : polylines)
             pl.translate(rotate_vector.second);
 
+    // Orca: round the corners of the trapezoids. The straight base lines of the triangular family
+    // have no corner to round.
+    smooth_polylines_corners(polylines, params.smooth_factor, scaled<double>(params.resolution));
+
     // Apply multiline fill
     multiline_fill(polylines, params, spacing);
 
@@ -3576,7 +3581,7 @@ Polylines FillLateralHoneycomb::fill_surface(const Surface *surface, const FillP
     //     |
     //     |
     // 0 --+--
-    //    / \
+    //    ⟋ ⟍
     // why inverted?
     // it makes determining some of the properties easier
     // and the two angled legs provide additional horizontal stiffness

src/libslic3r/Fill/Lightning/TreeNode.cpp

@@ -351,19 +351,23 @@ void Node::convertToPolylines(Polylines &output, const coord_t line_overlap) con
 {
     Polylines result;
     result.emplace_back();
-    convertToPolylines(0, result);
+    // Orca: the layers are filled in parallel, so they would consume a shared generator in a
+    // different order every run, and a model would not slice the same way twice. Each tree seeds
+    // its own from where it is rooted; one constant seed would start them all on the same pick.
+    std::mt19937_64 rng { uint64_t(PointHash{}(m_p)) };
+    convertToPolylines(0, result, rng);
     removeJunctionOverlap(result, line_overlap);
     append(output, std::move(result));
 }
 
-void Node::convertToPolylines(size_t long_line_idx, Polylines &output) const
+void Node::convertToPolylines(size_t long_line_idx, Polylines &output, std::mt19937_64 &rng) const
 {
     if (m_children.empty()) {
         output[long_line_idx].points.push_back(m_p);
         return;
     }
-    size_t first_child_idx = rand() % m_children.size();
-    m_children[first_child_idx]->convertToPolylines(long_line_idx, output);
+    const size_t first_child_idx = rng() % m_children.size();
+    m_children[first_child_idx]->convertToPolylines(long_line_idx, output, rng);
     output[long_line_idx].points.push_back(m_p);
 
     for (size_t idx_offset = 1; idx_offset < m_children.size(); idx_offset++) {
@@ -371,7 +375,7 @@ void Node::convertToPolylines(size_t long_line_idx, Polylines &output) const
         const Node& child = *m_children[child_idx];
         output.emplace_back();
         size_t child_line_idx = output.size() - 1;
-        child.convertToPolylines(child_line_idx, output);
+        child.convertToPolylines(child_line_idx, output, rng);
         output[child_line_idx].points.emplace_back(m_p);
     }
 }

src/libslic3r/Fill/Lightning/TreeNode.hpp

@@ -7,6 +7,7 @@
 #include <functional>
 #include <memory>
 #include <optional>
+#include <random>
 #include <vector>
 
 #include "../../EdgeGrid.hpp"
@@ -259,8 +260,9 @@ protected:
      * 
      * \param long_line a reference to a polyline in \p output which to continue building on in the recursion
      * \param output all branches in this tree connected into polylines
+     * \param rng the generator the junctions draw from, carried through the recursion
      */
-    void convertToPolylines(size_t long_line_idx, Polylines &output) const;
+    void convertToPolylines(size_t long_line_idx, Polylines &output, std::mt19937_64 &rng) const;
 
     void removeJunctionOverlap(Polylines &polylines, coord_t line_overlap) const;
 

src/libslic3r/Format/STEP.cpp

@@ -712,7 +712,7 @@ unsigned int Step::get_triangle_num(double linear_deflection, double angle_defle
                 return 0;
             }
         }
-    } catch(Exception e) {
+    } catch(const Exception &) {
         return 0;
     }
     

src/libslic3r/GCode.cpp

@@ -771,30 +771,31 @@ static std::vector<Vec2d> get_path_of_change_filament(const Print& print)
         return changes;
     }
 
+    // Clearance the tower-approach router keeps around the tower: the avoid box is
+    // inflated by this much before routing, and the inflated corners must stay on the
+    // bed for a route to be generated at all.
+    static constexpr float wipe_tower_routing_clearance = 2.f;
+
     // BBS
     // start_pos refers to the last position before the wipe_tower.
     // end_pos refers to the wipe tower's start_pos.
     // using the print coordinate system
-    Polyline WipeTowerIntegration::generate_path_to_wipe_tower(const Point& start_pos,const Point &end_pos , const BoundingBox& avoid_polygon , const BoundingBox& printer_bbx) const
+    Polyline WipeTowerIntegration::generate_path_to_wipe_tower(const Point& start_pos,const Point &end_pos , const BoundingBox& avoid_polygon , const Polygons& bed_polygons) const
     {
         Polyline    res;
-        coord_t         alpha = scaled(2.f); // offset distance
+        coord_t         alpha = scaled(wipe_tower_routing_clearance); // offset distance
         BoundingBox avoid_polygon_inner = avoid_polygon;
         avoid_polygon_inner.offset(alpha);
         coord_t width = avoid_polygon_inner.max[0] - avoid_polygon_inner.min[0];
-        Polygon bed_polygon = printer_bbx.polygon();
         Vec2f v(1, 0);                                                      // the first print direction of end_pos.
         if (abs(end_pos[0] - avoid_polygon_inner.min[0]) < width / 2) v = -v; // judge whether the wipe tower's infill goes to the left or right.
-        // Judge whether the avoid_polygon_inner is outside the printer_bbx.
+        // Judge whether the avoid_polygon_inner is outside the bed. The real printable
+        // outline is tested (not its bounding box), so on circular/custom beds corners
+        // hanging off the bed are rejected.
         // If so, do nothing and just go directly to the end_pos.
-        bool is_bbx_in_bed = true;
         Points avoid_points  = avoid_polygon_inner.polygon().points;
-        for (auto &wipe_tower_bbx_p : avoid_points) {
-            if (ClipperLib::PointInPolygon(wipe_tower_bbx_p, bed_polygon.points) != 1) {
-                is_bbx_in_bed = false;
-                break;
-            }
-        }
+        const bool is_bbx_in_bed = std::all_of(avoid_points.begin(), avoid_points.end(),
+            [&bed_polygons](const Point &pt) { return contains(bed_polygons, pt, /*border_result=*/false); });
         if (!is_bbx_in_bed) {
             res.points.push_back(end_pos);
             return res;
@@ -901,27 +902,17 @@ static std::vector<Vec2d> get_path_of_change_filament(const Print& print)
         return Eigen::Rotation2Df(alpha) * (pt + m_rib_offset) + m_wipe_tower_pos;
     }
 
-    // Printable-area bounds for tower-approach routing, in object coordinates (shared by
-    // the BBL avoid-perimeter path in append_tcr and the Type2 skip-points router).
-    // Multi-nozzle: clamp the travel bounds to the region every extruder can reach
-    // (get_extruder_shared_printable_polygon) instead of the full bed. Gated on the
-    // multi-nozzle predicate so every existing single/dual printer keeps the historic
-    // full-printable_area routing byte-identical.
-    BoundingBox WipeTowerIntegration::printer_travel_bounds(GCode &gcodegen) const
+    // Bed outline the tower-approach router plans against, in object coordinates. The real
+    // outline is returned, not its bounding box, so the router's containment tests fail off
+    // the bed on circular/custom shapes; the multi-nozzle narrowing lives in the accessor.
+    Polygons WipeTowerIntegration::shared_printable_area(GCode &gcodegen) const
     {
-        const Vec2f plate_origin_2d(m_plate_origin(0), m_plate_origin(1));
-        BoundingBox printer_bbx;
-        if (is_multi_nozzle_printer(gcodegen.m_config)) {
-            printer_bbx     = get_extents(gcodegen.m_print->get_extruder_shared_printable_polygon());
-            printer_bbx.min = wipe_tower_point_to_object_point(gcodegen, unscaled<float>(printer_bbx.min) + plate_origin_2d);
-            printer_bbx.max = wipe_tower_point_to_object_point(gcodegen, unscaled<float>(printer_bbx.max) + plate_origin_2d);
-        } else {
-            Points bed_points;
-            for (const auto& p : gcodegen.m_config.printable_area.values)
-                bed_points.push_back(wipe_tower_point_to_object_point(gcodegen, p.cast<float>() + plate_origin_2d));
-            printer_bbx = BoundingBox(bed_points);
-        }
-        return printer_bbx;
+        // The frame change is a pure translation, so transform the origin once.
+        const Point offset = wipe_tower_point_to_object_point(gcodegen, Vec2f(m_plate_origin(0), m_plate_origin(1)));
+        Polygons    bed_polygons = gcodegen.m_print->get_extruder_shared_printable_polygon();
+        for (Polygon &poly : bed_polygons)
+            poly.translate(offset);
+        return bed_polygons;
     }
 
     // With skip points enabled the Type2 tower wall has an opening at each toolchange's
@@ -936,15 +927,37 @@ static std::vector<Vec2d> get_path_of_change_filament(const Print& print)
         if (!WipeTower2::use_gap_wall(gcodegen.m_config))
             return {};
         const Vec2f plate_origin_2d(m_plate_origin(0), m_plate_origin(1));
-        // Transform the tower-local bbx corners exactly like the tcr points; a rotated
-        // tower gets a conservative axis-aligned envelope.
-        Polygon avoid_points = scaled(m_wipe_tower_bbx).polygon();
-        for (auto& p : avoid_points.points)
-            p = wipe_tower_point_to_object_point(gcodegen, transform_wt2_pt(unscale(p).cast<float>()) + plate_origin_2d);
-        BoundingBox avoid_bbx(avoid_points.points);
-        if (avoid_bbx.contains(route_start))
+        // Transform tower-local corners exactly like the tcr points; a rotated tower gets a
+        // conservative axis-aligned envelope from the result.
+        auto tower_polygon = [&](const BoundingBoxf &bbx) {
+            Polygon poly = scaled(bbx).polygon();
+            for (Point &p : poly.points)
+                p = wipe_tower_point_to_object_point(gcodegen, transform_wt2_pt(unscale(p).cast<float>()) + plate_origin_2d);
+            return poly;
+        };
+        // The avoid envelope covers the first-layer brim (and rib flare), which a travel may
+        // cross freely: early-out only when the approach already starts over the tower body
+        // itself, so a start between the wall and the brim edge still gets routed in through
+        // the wall opening. Test the rotated polygon, not its bounding box — at angles off the
+        // axes the box's corner triangles cover most of the brim ring.
+        const float body_width = gcodegen.m_config.wipe_tower_wall_type.value == WipeTowerWallType::wtwRib ? m_wipe_tower_depth : m_right;
+        if (tower_polygon(BoundingBoxf(Vec2d(0., 0.), Vec2d(body_width, m_wipe_tower_depth))).contains(route_start))
             return {};
-        Polyline    travel_polyline = generate_path_to_wipe_tower(route_start, start_wipe_pos, avoid_bbx, printer_travel_bounds(gcodegen));
+
+        const Polygons bed       = shared_printable_area(gcodegen);
+        BoundingBox    avoid_bbx = get_extents(tower_polygon(m_wipe_tower_bbx));
+        // The inflated corners must stay on the bed for the router to generate a route at all:
+        // clamp the box against the bed shrunk by the clearance the router adds, so a tower
+        // parked near the bed edge is still routed along the clamped side instead of always
+        // travelling straight across the tower.
+        BoundingBox clamp_bbx = get_extents(bed);
+        clamp_bbx.offset(-(scaled(wipe_tower_routing_clearance) + SCALED_EPSILON));
+        avoid_bbx.min = avoid_bbx.min.cwiseMax(clamp_bbx.min);
+        avoid_bbx.max = avoid_bbx.max.cwiseMin(clamp_bbx.max);
+        if (avoid_bbx.min.x() >= avoid_bbx.max.x() || avoid_bbx.min.y() >= avoid_bbx.max.y())
+            return {};
+
+        Polyline    travel_polyline = generate_path_to_wipe_tower(route_start, start_wipe_pos, avoid_bbx, bed);
         std::string gcode;
         // The polyline's last point is start_wipe_pos itself — emitted by the caller.
         for (size_t i = 0; i + 1 < travel_polyline.points.size(); ++i)
@@ -1140,8 +1153,8 @@ static std::vector<Vec2d> get_path_of_change_filament(const Print& print)
 
                 float old_retract_length = (old_filament_id != -1) ? full_config.retraction_length.get_at(old_fi) : 0;
                 float new_retract_length = full_config.retraction_length.get_at(new_fi);
-                float old_retract_length_toolchange = (old_filament_id != -1) ? full_config.retract_length_toolchange.get_at(old_filament_id) : 0;
-                float new_retract_length_toolchange = full_config.retract_length_toolchange.get_at(new_filament_id);
+                float old_retract_length_toolchange = (old_filament_id != -1) ? full_config.retract_length_toolchange.get_at(old_fi) : 0;
+                float new_retract_length_toolchange = full_config.retract_length_toolchange.get_at(new_fi);
                 int old_filament_temp = (old_filament_id != -1) ? (gcodegen.on_first_layer()? full_config.nozzle_temperature_initial_layer.get_at(old_fi) : full_config.nozzle_temperature.get_at(old_fi)) : 210;
                 int new_filament_temp = gcodegen.on_first_layer() ? full_config.nozzle_temperature_initial_layer.get_at(new_fi) : full_config.nozzle_temperature.get_at(new_fi);
                 Vec3d nozzle_pos = gcode_writer.get_position();
@@ -1325,7 +1338,7 @@ static std::vector<Vec2d> get_path_of_change_filament(const Print& print)
                 Vec2f       gcode_last_pos2d{gcode_last_pos[0], gcode_last_pos[1]};
                 Point       gcode_last_pos2d_object = gcodegen.gcode_to_point(gcode_last_pos2d.cast<double>() + plate_origin_2d.cast<double>());
                 Point       start_wipe_pos          = wipe_tower_point_to_object_point(gcodegen, tool_change_start_pos + plate_origin_2d);
-                BoundingBox avoid_bbx, printer_bbx = printer_travel_bounds(gcodegen);
+                BoundingBox avoid_bbx;
                 {
                     // set avoid_bbx
                     avoid_bbx            = scaled(m_wipe_tower_bbx);
@@ -1337,7 +1350,7 @@ static std::vector<Vec2d> get_path_of_change_filament(const Print& print)
                     avoid_bbx = BoundingBox(avoid_points.points);
                 }
                 std::string travel_to_wipe_tower_gcode;
-                Polyline    travel_polyline = generate_path_to_wipe_tower(gcode_last_pos2d_object, start_wipe_pos, avoid_bbx, printer_bbx);
+                Polyline    travel_polyline = generate_path_to_wipe_tower(gcode_last_pos2d_object, start_wipe_pos, avoid_bbx, shared_printable_area(gcodegen));
 
                 for (size_t i = 0; i < travel_polyline.points.size(); ++i) {
                     const auto &p = travel_polyline.points[i];
@@ -1557,7 +1570,8 @@ static std::vector<Vec2d> get_path_of_change_filament(const Print& print)
                     interface_temp = gcodegen.config().nozzle_temperature_range_high.get_at(new_extruder_id);
                 toolchange_temp_override = interface_temp;
             }
-            toolchange_gcode_str = gcodegen.set_extruder(new_extruder_id, tcr.print_z, false, toolchange_temp_override); // TODO: toolchange_z vs print_z
+            toolchange_gcode_str = gcodegen.set_extruder(new_extruder_id, tcr.print_z, false, toolchange_temp_override,
+                                                         WipeTower2::wait_for_temp_enabled(gcodegen.m_config)); // TODO: toolchange_z vs print_z
             if (!travel_to_tower_now && !tcr.priming && WipeTower2::use_gap_wall(gcodegen.m_config)) {
                 // The tool changed in place (multi-tool printer without ramming), so the
                 // tower entry is the tcr's own positioning move — a straight line across
@@ -1708,7 +1722,7 @@ static std::vector<Vec2d> get_path_of_change_filament(const Print& print)
                 std::string trimmed = line;
                 trimmed.erase(0, trimmed.find_first_not_of(" \t"));
                 bool skip_line = false;
-                if (boost::starts_with(trimmed, "M109")) {
+                if (boost::starts_with(trimmed, "M109") && trimmed.find(WipeTower2::wait_for_temp_tag()) == std::string::npos) {
                     bool matches_extruder = true;
                     if (trimmed.find('T') != std::string::npos)
                         matches_extruder = trimmed.find(t_token) != std::string::npos;
@@ -2932,6 +2946,7 @@ void GCode::_do_export(Print& print, GCodeOutputStream &file, ThumbnailsGenerato
     DoExport::init_gcode_processor(print.config(), m_processor, m_silent_time_estimator_enabled,
                                    print.get_layered_nozzle_group_result());
     const bool is_bbl_printers = print.is_BBL_printer();
+    const bool skip_config_block = print.config().gcode_skip_config_block;
     const WipeTowerType wipe_tower_type = print.wipe_tower_type();
     m_calib_config.clear();
     // resets analyzer's tracking data
@@ -3144,7 +3159,7 @@ void GCode::_do_export(Print& print, GCodeOutputStream &file, ThumbnailsGenerato
       // as configuration key / value pairs to be parsable by older versions of
       // PrusaSlicer G-code viewer.
     {
-        if (is_bbl_printers) {
+        if (is_bbl_printers && !skip_config_block) {
             file.write("; CONFIG_BLOCK_START\n");
             std::string full_config;
             append_full_config(print, full_config);
@@ -4182,23 +4197,25 @@ void GCode::_do_export(Print& print, GCodeOutputStream &file, ThumbnailsGenerato
                 GCodeProcessor::ETags::Estimated_Printing_Time_Placeholder)
             .c_str());
       file.write("\n");
-      file.write("; CONFIG_BLOCK_START\n");
-      std::string full_config;
-      append_full_config(print, full_config);
-      if (!full_config.empty())
-        file.write(full_config);
+      if (!skip_config_block) {
+          file.write("; CONFIG_BLOCK_START\n");
+          std::string full_config;
+          append_full_config(print, full_config);
+          if (!full_config.empty())
+            file.write(full_config);
 
-      // SoftFever: write compatiple info
-      int first_layer_bed_temperature = get_bed_temperature(0, true, print.config().curr_bed_type);
-      file.write_format("; first_layer_bed_temperature = %d\n", first_layer_bed_temperature);
-      file.write_format("; bed_shape = %s\n", print.full_print_config().opt_serialize("printable_area").c_str());
-      file.write_format("; first_layer_temperature = %d\n", print.config().nozzle_temperature_initial_layer.get_at(0));
-      file.write_format("; first_layer_height = %.3f\n", print.config().initial_layer_print_height.value);
-        
-        //SF TODO
-//      file.write_format("; variable_layer_height = %d\n", print.ad.adaptive_layer_height ? 1 : 0);
-   
-      file.write("; CONFIG_BLOCK_END\n\n");
+          // SoftFever: write compatiple info
+          int first_layer_bed_temperature = get_bed_temperature(0, true, print.config().curr_bed_type);
+          file.write_format("; first_layer_bed_temperature = %d\n", first_layer_bed_temperature);
+          file.write_format("; bed_shape = %s\n", print.full_print_config().opt_serialize("printable_area").c_str());
+          file.write_format("; first_layer_temperature = %d\n", print.config().nozzle_temperature_initial_layer.get_at(0));
+          file.write_format("; first_layer_height = %.3f\n", print.config().initial_layer_print_height.value);
+
+            //SF TODO
+//          file.write_format("; variable_layer_height = %d\n", print.ad.adaptive_layer_height ? 1 : 0);
+
+          file.write("; CONFIG_BLOCK_END\n\n");
+      } // !skip_config_block
 
     }
     file.write("\n");
@@ -5781,7 +5798,7 @@ LayerResult GCode::process_layer(
     // add tag for processor
     gcode += ";" + GCodeProcessor::reserved_tag(GCodeProcessor::ETags::Layer_Change) + "\n";
     // export layer z
-    char buf[64];
+    char buf[80];
     sprintf(buf, print.is_BBL_printer() ? "; Z_HEIGHT: %g\n" : ";Z:%g\n", print_z);
     gcode += buf;
     // export layer height
@@ -7146,6 +7163,7 @@ void GCode::append_full_config(const Print &print, std::string &str)
         "farthest_point_timelapse"sv,
         "compatible_printers"sv,
         "compatible_prints"sv,
+        "filament_colour_type"sv,
         "print_host"sv,
         "print_host_webui"sv,
         "printhost_apikey"sv,
@@ -8099,8 +8117,7 @@ std::string GCode::_extrude(const ExtrusionPath &path, std::string description,
             if (sloped) {
                 speed = std::min(speed, m_config.scarf_joint_speed.get_abs_value(speed));
             }
-        } 
-        else if(path.role() == erInternalBridgeInfill) {
+        } else if(path.role() == erInternalBridgeInfill) {
             speed = m_config.get_abs_value_at("internal_bridge_speed", get_nozzle_config_index(m_writer->filament()->id()));
         } else if (path.role() == erOverhangPerimeter || path.role() == erSupportTransition || path.role() == erBridgeInfill) {
             speed = NOZZLE_CONFIG(bridge_speed);
@@ -8111,7 +8128,10 @@ std::string GCode::_extrude(const ExtrusionPath &path, std::string description,
         } else if (path.role() == erTopSolidInfill) {
             speed = NOZZLE_CONFIG(top_surface_speed);
         } else if (path.role() == erIroning) {
-            speed = m_config.get_abs_value("ironing_speed");
+            const size_t filament_idx = get_filament_config_index(m_writer->filament()->id());
+            speed = m_config.filament_ironing_speed.is_nil(filament_idx)
+                ? m_config.get_abs_value("ironing_speed")
+                : m_config.filament_ironing_speed.get_at(filament_idx);
         } else if (path.role() == erBottomSurface) {
             speed = NOZZLE_CONFIG(initial_layer_infill_speed);
         } else if (path.role() == erGapFill) {
@@ -9419,7 +9439,7 @@ void GCode::update_placeholder_parser_with_variant_params()
     }
 }
 
-std::string GCode::set_extruder(unsigned int new_filament_id, double print_z, bool by_object, int toolchange_temp_override)
+std::string GCode::set_extruder(unsigned int new_filament_id, double print_z, bool by_object, int toolchange_temp_override, bool defer_temp_wait)
 {
     int new_extruder_id = get_extruder_id(new_filament_id);
     if (!m_writer->need_toolchange(new_filament_id))
@@ -9518,7 +9538,7 @@ std::string GCode::set_extruder(unsigned int new_filament_id, double print_z, bo
     // per-layer nozzle grouping; resolve the column instead of indexing by the filament id.
     size_t new_fi = get_filament_config_index((int)new_filament_id);
     float new_retract_length = m_config.retraction_length.get_at(new_fi);
-    float new_retract_length_toolchange = m_config.retract_length_toolchange.get_at(new_filament_id);
+    float new_retract_length_toolchange = m_config.retract_length_toolchange.get_at(new_fi);
     int new_filament_temp = this->on_first_layer() ? m_config.nozzle_temperature_initial_layer.get_at(new_fi) : m_config.nozzle_temperature.get_at(new_fi);
     // BBS: if print_z == 0 use first layer temperature
     if (abs(print_z) < EPSILON)
@@ -9526,6 +9546,24 @@ std::string GCode::set_extruder(unsigned int new_filament_id, double print_z, bo
     if (toolchange_temp_override > 0)
         new_filament_temp = toolchange_temp_override;
 
+    // With wait_for_temp_on_wipe_tower the blocking M109 is deferred to the wipe tower, so raise
+    // the incoming filament's target here — ahead of the tool change rather than after it — and
+    // let the heat-up overlap the change itself as well as the travel to the tower. The command
+    // always carries an explicit tool index (the option is off for single extruder MM, so the
+    // writer emits one), leaving the outgoing filament that pre_toolchange just dropped to its
+    // standby temperature alone. nozzle_temperature == 0 means "use the first layer temperature".
+    if (defer_temp_wait) {
+        // Target what the tower will wait on. It waits on the first layer temperature not only on
+        // the first layer but also while priming, which runs before any layer is set: there
+        // on_first_layer() is false and print_z is the initial layer height, so neither test above
+        // catches it. nozzle_temperature == 0 means "use the first layer temperature" as well.
+        int preheat_temp = new_filament_temp;
+        if (toolchange_temp_override <= 0 && (m_layer == nullptr || preheat_temp <= 0))
+            preheat_temp = m_config.nozzle_temperature_initial_layer.get_at(new_fi);
+        if (preheat_temp > 0)
+            gcode += m_writer->set_temperature(preheat_temp, false, new_filament_id);
+    }
+
     Vec3d nozzle_pos = m_writer->get_position();
     float old_retract_length, old_retract_length_toolchange, wipe_volume;
     int old_filament_temp, old_filament_e_feedrate;
@@ -9549,7 +9587,7 @@ std::string GCode::set_extruder(unsigned int new_filament_id, double print_z, bo
         // gap-filled carry-forward, so its current-layer column matches the nozzle it occupies.
         size_t old_fi = get_filament_config_index(old_filament_id);
         old_retract_length = m_config.retraction_length.get_at(old_fi);
-        old_retract_length_toolchange = m_config.retract_length_toolchange.get_at(old_filament_id);
+        old_retract_length_toolchange = m_config.retract_length_toolchange.get_at(old_fi);
         old_filament_temp = this->on_first_layer()? m_config.nozzle_temperature_initial_layer.get_at(old_fi) : m_config.nozzle_temperature.get_at(old_fi);
 
         //During the filament change, the extruder will extrude an extra length of grab_length for the corresponding detection, so the purge can reduce this length.
@@ -9829,8 +9867,10 @@ std::string GCode::set_extruder(unsigned int new_filament_id, double print_z, bo
         }
         check_add_eol(gcode);
     }
-    // Set the new extruder to the operating temperature.
-    if (m_ooze_prevention.enable)
+    // Set the new extruder to the operating temperature. With defer_temp_wait the target was
+    // already raised before the tool change and the blocking wait belongs to the wipe tower
+    // generator, so there is nothing left to restore here.
+    if (m_ooze_prevention.enable && !defer_temp_wait)
         gcode += m_ooze_prevention.post_toolchange(*this);
 
     if (m_config.enable_pressure_advance.get_at(new_filament_id)) {

src/libslic3r/GCode.hpp

@@ -133,11 +133,11 @@ public:
 private:
     WipeTowerIntegration& operator=(const WipeTowerIntegration&);
     std::string append_tcr(GCode &gcodegen, const WipeTower::ToolChangeResult &tcr, int new_extruder_id, double z = -1.) const;
-    Polyline generate_path_to_wipe_tower(const Point &start_pos, const Point &end_pos, const BoundingBox &avoid_polygon, const BoundingBox &printer_bbx) const;
+    Polyline generate_path_to_wipe_tower(const Point &start_pos, const Point &end_pos, const BoundingBox &avoid_polygon, const Polygons &bed_polygons) const;
     std::string append_tcr2(GCode &gcodegen, const WipeTower::ToolChangeResult &tcr, int new_extruder_id, double z = -1.) const;
     std::string travel_to_tower_gap(GCode &gcodegen, const Point &route_start, const Point &start_wipe_pos) const;
     Vec2f transform_wt2_pt(const Vec2f &pt) const;
-    BoundingBox printer_travel_bounds(GCode &gcodegen) const;
+    Polygons shared_printable_area(GCode &gcodegen) const;
 
     // Postprocesses gcode: rotates and moves G1 extrusions and returns result
     std::string post_process_wipe_tower_moves(const WipeTower::ToolChangeResult& tcr, const Vec2f& translation, float angle) const;
@@ -187,7 +187,7 @@ struct LayerResult {
     // It is used for the pressure equalizer because it needs to buffer one layer back.
     bool        nop_layer_result { false };
 
-    static LayerResult make_nop_layer_result() { return {"", std::numeric_limits<coord_t>::max(), false, false, true}; }
+    static LayerResult make_nop_layer_result() { return {"", std::numeric_limits<size_t>::max(), false, false, true}; }
 };
 
 class GCode {
@@ -267,7 +267,7 @@ public:
     std::string     retract(bool toolchange = false, bool is_last_retraction = false, LiftType lift_type = LiftType::NormalLift, bool apply_instantly = false, ExtrusionRole role = erNone);
     // extra_retract forwards a PETG pre-extrusion over-extrusion; default 0 -> identical to the plain deretract.
     std::string     unretract(float extra_retract = 0.f) { return m_writer->unlift() + m_writer->unretract(extra_retract); }
-    std::string     set_extruder(unsigned int extruder_id, double print_z, bool by_object=false, int toolchange_temp_override = -1);
+    std::string     set_extruder(unsigned int extruder_id, double print_z, bool by_object=false, int toolchange_temp_override = -1, bool defer_temp_wait = false);
     bool is_BBL_Printer();
     WipeTowerType wipe_tower_type();
 

src/libslic3r/GCode/ExtrusionProcessor.hpp

@@ -19,6 +19,7 @@
 #include <algorithm>
 #include <cmath>
 #include <cstddef>
+#include <functional>
 #include <limits>
 #include <numeric>
 #include <unordered_map>
@@ -39,7 +40,11 @@ std::vector<ExtendedPoint<L::Dim>> estimate_points_properties(const POINTS&
                                                               const AABBTreeLines::LinesDistancer<L>& unscaled_prev_layer,
                                                               float                                   flow_width,
                                                               float                                   max_line_length = -1.0f,
-                                                              float                                   min_distance    = -1.0f)
+                                                              float                                   min_distance    = -1.0f,
+                                                              // Maps an overhang distance onto the speed it will be printed at. Interior sampling
+                                                              // needs it to tell which of the points it could add would change the G-code, and is
+                                                              // skipped without it.
+                                                              const std::function<float(float)>&      distance_to_speed = {})
 {
     bool   looped     = input_points.front() == input_points.back();
     std::function<size_t(size_t,size_t)> get_prev_index = [](size_t idx, size_t count) {
@@ -120,6 +125,107 @@ std::vector<ExtendedPoint<L::Dim>> estimate_points_properties(const POINTS&
         points.push_back(next_point);
     }
 
+    // ORCA: Interior sampling
+    // The passes below infer the support under a span from its endpoints alone, so an interior that is supported
+    // differently from both ends is invisible to them: the outer perimeter of an overhang whose ends are caged by
+    // full height walls reads as supported along its whole length. Probe the interior, keep the samples the
+    // endpoint interpolation fails to predict, and bisect either side of each one, so a span that is only partly
+    // unsupported gets points where its support actually changes instead of one reading spread across all of it.
+    if (PREV_LAYER_BOUNDARY_OFFSET && ADD_INTERSECTIONS && min_distance > 0 && distance_to_speed) {
+        // Probe at least this densely before treating matching samples as evidence that a span is uniform. The
+        // segmentation pass below only splits lines of 2mm or more, and every pass here drops points closer
+        // together than min_spacing, so finer discovery would not produce a more precise speed transition.
+        const double max_probe_spacing = std::max(2., 4. * min_spacing);
+        // A backstop for that length test, which on a non-finite length would never be met.
+        constexpr int max_bisection_depth = 10;
+        // Whether two readings are interchangeable. A segment is printed at the lower of the speeds its ends
+        // read, so a sample that agrees on speed with what is already known cannot change the G-code, whatever
+        // its distance says. The distances themselves are far too coarse a stand-in for this: the speed sections
+        // interpolate, so readings a small fraction of min_distance apart can still be tens of mm/s apart.
+        // The tolerance matches the one GCode.cpp applies when it decides a path has a variable speed at all.
+        auto same_speed = [&distance_to_speed](float a, float b) {
+            return std::abs(distance_to_speed(a) - distance_to_speed(b)) <= 1.f;
+        };
+        // Whether the first reading is printed slower than the second, once they are known to differ.
+        auto prints_slower = [&distance_to_speed](float a, float b) { return distance_to_speed(a) < distance_to_speed(b); };
+
+        // Part of a segment still to bisect: its positions along the segment and bisections left.
+        struct Subspan { double t0, t1; int depth; };
+
+        std::vector<ExtendedPoint<L::Dim>>    sampled_points; // Populated lazily, on the first insertion
+        std::vector<std::pair<double, float>> interior;       // Samples of one segment, keyed by position along it
+        std::vector<Subspan>                  pending;
+
+        for (size_t point_idx = 0; point_idx + 1 < points.size(); ++point_idx) {
+            const ExtendedPoint<L::Dim>& curr     = points[point_idx];
+            const ExtendedPoint<L::Dim>& next     = points[point_idx + 1];
+            const Vec                    step     = next.position - curr.position;
+            const double                 line_len = step.norm();
+
+            interior.clear();
+            if (line_len >= max_probe_spacing)
+                pending.push_back({0., 1., max_bisection_depth});
+
+            while (!pending.empty()) {
+                const Subspan subspan = pending.back();
+                pending.pop_back();
+                if (subspan.depth <= 0 || (subspan.t1 - subspan.t0) * line_len < max_probe_spacing)
+                    continue;
+
+                const double t = 0.5 * (subspan.t0 + subspan.t1);
+                auto [distance, nearest_line, x] = unscaled_prev_layer.template distance_from_lines_extra<SIGNED_DISTANCE>(
+                    (curr.position + t * step).template cast<AABBScalar>());
+                const float sampled = float(distance + boundary_offset);
+
+                interior.emplace_back(t, sampled);
+                pending.push_back({subspan.t0, t, subspan.depth - 1});
+                pending.push_back({t, subspan.t1, subspan.depth - 1});
+            }
+
+            if (!interior.empty()) {
+                std::sort(interior.begin(), interior.end(),
+                          [](const std::pair<double, float>& l, const std::pair<double, float>& r) { return l.first < r.first; });
+                // Coarse probing keeps every sample it took until this pass can see which ones bracket a speed
+                // transition. Matching samples cannot be discarded during discovery: one may be the last
+                // supported point before a narrow unsupported pocket found by a later probe.
+                size_t kept = 0;
+                for (size_t i = 0; i < interior.size(); ++i) {
+                    const float sample    = interior[i].second;
+                    const bool  at_start  = kept == 0;                     // Nothing kept yet, so the segment's own start precedes it
+                    const bool  at_end    = i + 1 == interior.size();      // And nothing follows the last sample but the segment's end
+                    const float before    = at_start ? curr.distance : interior[kept - 1].second;
+                    const float after     = at_end ? next.distance : interior[i + 1].second;
+                    // A sample is worth a point in the path only where it prints at a different speed from the
+                    // readings either side of it. Differing from one of the segment's own ends is not enough on
+                    // its own where the sample is the faster of the two: the segmentation pass below already
+                    // ends the slowdown an end reads, at a distance taken from how far out that end is rather
+                    // than from wherever bisection happened to stop, and a point here would leave the span
+                    // beside the end too short for that pass to run at all. Support an end cannot account for,
+                    // where the interior is the slower reading, is exactly what this pass is here to find.
+                    const bool worth_before = !same_speed(sample, before) && (!at_start || prints_slower(sample, before));
+                    const bool worth_after  = !same_speed(sample, after) && (!at_end || prints_slower(sample, after));
+                    if (worth_before || worth_after)
+                        interior[kept++] = interior[i];
+                }
+                interior.resize(kept);
+            }
+
+            if (!interior.empty() && sampled_points.empty()) {
+                sampled_points.reserve(points.size() + 8);
+                sampled_points.assign(points.begin(), points.begin() + point_idx + 1);
+            }
+            if (!sampled_points.empty()) {
+                // Only a sub-span of max_probe_spacing or more is ever bisected, so these sit at least
+                // 2 * min_spacing apart, and need none of the filtering the passes either side of this one do.
+                for (const auto& [t, distance] : interior)
+                    sampled_points.push_back({curr.position + t * step, distance});
+                sampled_points.push_back(next);
+            }
+        }
+        if (!sampled_points.empty())
+            points = std::move(sampled_points);
+    }
+
     // Segmentation handling
     if (PREV_LAYER_BOUNDARY_OFFSET && ADD_INTERSECTIONS) {
         std::vector<ExtendedPoint<L::Dim>> new_points;
@@ -362,9 +468,28 @@ public:
             smallest_distance_with_lower_speed=-1.f;
 
         // Orca: Pass to the point properties estimator the smallest ovehang distance that triggers a slowdown (smallest_distance_with_lower_speed)
+        auto calculate_speed = [&speed_sections, &original_speed](float distance) {
+            float final_speed;
+            if (distance <= speed_sections.front().first) {
+                final_speed = original_speed;
+            } else if (distance >= speed_sections.back().first) {
+                final_speed = speed_sections.back().second;
+            } else {
+                size_t section_idx = 0;
+                while (distance > speed_sections[section_idx + 1].first) {
+                    section_idx++;
+                }
+                float t = (distance - speed_sections[section_idx].first) /
+                          (speed_sections[section_idx + 1].first - speed_sections[section_idx].first);
+                t           = std::clamp(t, 0.0f, 1.0f);
+                final_speed = (1.0f - t) * speed_sections[section_idx].second + t * speed_sections[section_idx + 1].second;
+            }
+            return round(final_speed);
+        };
+
         std::vector<ExtendedPoint<3>> extended_points =
             estimate_points_properties<true, true, true, true>(path.polyline.points, prev_layer_boundaries[current_object], path.width, -1,
-                                                               smallest_distance_with_lower_speed);
+                                                               smallest_distance_with_lower_speed, calculate_speed);
         const auto width_inv = 1.0f / path.width;
         std::vector<ProcessedPoint> processed_points;
         processed_points.reserve(extended_points.size());
@@ -423,25 +548,6 @@ public:
                 }
             }	
 
-            auto calculate_speed = [&speed_sections, &original_speed](float distance) {
-                float final_speed;
-                if (distance <= speed_sections.front().first) {
-                    final_speed = original_speed;
-                } else if (distance >= speed_sections.back().first) {
-                    final_speed = speed_sections.back().second;
-                } else {
-                    size_t section_idx = 0;
-                    while (distance > speed_sections[section_idx + 1].first) {
-                        section_idx++;
-                    }
-                    float t = (distance - speed_sections[section_idx].first) /
-                              (speed_sections[section_idx + 1].first - speed_sections[section_idx].first);
-                    t           = std::clamp(t, 0.0f, 1.0f);
-                    final_speed = (1.0f - t) * speed_sections[section_idx].second + t * speed_sections[section_idx + 1].second;
-                }
-                return round(final_speed);
-            };
-            
             float extrusion_speed = std::min(calculate_speed(curr.distance), calculate_speed(next.distance));
             // ORCA: Clamp resulting speed to lowest of calculated speed based on the overhang values and the current speed
             // Fixes bug where resulting overhang speed is higher than the current speed due to (for example) volumetric flow limits.

src/libslic3r/GCode/GCodeProcessor.cpp

@@ -298,6 +298,7 @@ void GCodeProcessor::TimeMachine::State::reset()
     //BBS
     enter_direction = { 0.0f, 0.0f, 0.0f };
     exit_direction = { 0.0f, 0.0f, 0.0f };
+    jd_unit_vec = { 0.0f, 0.0f, 0.0f, 0.0f };
 }
 
 void GCodeProcessor::TimeMachine::CustomGCodeTime::reset()
@@ -5107,6 +5108,10 @@ void GCodeProcessor::process_G1(const std::array<std::optional<double>, 4>& axes
         if (!is_extrusion_only_move(delta_pos))
             curr.enter_direction = curr.enter_direction / norm;
         curr.exit_direction = curr.enter_direction;
+        curr.jd_unit_vec = Vec4f(static_cast<float>(delta_pos[X]),
+                                 static_cast<float>(delta_pos[Y]),
+                                 static_cast<float>(delta_pos[Z]),
+                                 static_cast<float>(delta_pos[E])).normalized();
 
         TimeBlock block;
         block.move_type = type;
@@ -5189,22 +5194,32 @@ void GCodeProcessor::process_G1(const std::array<std::optional<double>, 4>& axes
 
         block.acceleration = acceleration;
 
-        // calculates block exit feedrate
-        curr.safe_feedrate = block.feedrate_profile.cruise;
+        static const float PREVIOUS_FEEDRATE_THRESHOLD = 0.0001f;
+        const bool has_prev_move = !blocks.empty() && prev.feedrate > PREVIOUS_FEEDRATE_THRESHOLD;
 
-        for (unsigned char a = X; a <= E; ++a) {
-            float axis_max_jerk = get_axis_max_jerk(static_cast<PrintEstimatedStatistics::ETimeMode>(i), static_cast<Axis>(a));
-            if (curr.abs_axis_feedrate[a] > axis_max_jerk)
-                curr.safe_feedrate = std::min(curr.safe_feedrate, axis_max_jerk);
+        // Orca: junction deviation where the firmware uses it (Klipper always, Marlin 2 with M205 J).
+        // Negative leaves the classic jerk path below unchanged.
+        const float vmax_junction_jd = calc_vmax_junction_deviation(block, prev, curr, has_prev_move,
+                                                                    static_cast<PrintEstimatedStatistics::ETimeMode>(i));
+        const bool use_junction_deviation = vmax_junction_jd >= 0.0f;
+
+        // calculates block exit feedrate. Junction deviation has no per axis jerk floor, so a move is
+        // free to start from rest.
+        curr.safe_feedrate = use_junction_deviation ? 0.0f : block.feedrate_profile.cruise;
+
+        if (!use_junction_deviation) {
+            for (unsigned char a = X; a <= E; ++a) {
+                float axis_max_jerk = get_axis_max_jerk(static_cast<PrintEstimatedStatistics::ETimeMode>(i), static_cast<Axis>(a));
+                if (curr.abs_axis_feedrate[a] > axis_max_jerk)
+                    curr.safe_feedrate = std::min(curr.safe_feedrate, axis_max_jerk);
+            }
         }
 
         block.feedrate_profile.exit = curr.safe_feedrate;
 
-        static const float PREVIOUS_FEEDRATE_THRESHOLD = 0.0001f;
-
         // calculates block entry feedrate
-        float vmax_junction = curr.safe_feedrate;
-        if (!blocks.empty() && prev.feedrate > PREVIOUS_FEEDRATE_THRESHOLD) {
+        float vmax_junction = use_junction_deviation ? vmax_junction_jd : curr.safe_feedrate;
+        if (!use_junction_deviation && has_prev_move) {
             bool prev_speed_larger = prev.feedrate > block.feedrate_profile.cruise;
             float smaller_speed_factor = prev_speed_larger ? (block.feedrate_profile.cruise / prev.feedrate) : (prev.feedrate / block.feedrate_profile.cruise);
             // Pick the smaller of the nominal speeds. Higher speed shall not be achieved at the junction during coasting.
@@ -5471,6 +5486,10 @@ void GCodeProcessor::process_VG1(const GCodeReader::GCodeLine& line)
         if (!is_extrusion_only_move(delta_pos))
             curr.enter_direction = curr.enter_direction / norm;
         curr.exit_direction = curr.enter_direction;
+        curr.jd_unit_vec = Vec4f(static_cast<float>(delta_pos[X]),
+                                 static_cast<float>(delta_pos[Y]),
+                                 static_cast<float>(delta_pos[Z]),
+                                 static_cast<float>(delta_pos[E])).normalized();
 
         TimeBlock block;
         block.move_type = type;
@@ -5551,22 +5570,32 @@ void GCodeProcessor::process_VG1(const GCodeReader::GCodeLine& line)
 
         block.acceleration = acceleration;
 
-        // calculates block exit feedrate
-        curr.safe_feedrate = block.feedrate_profile.cruise;
+        static const float PREVIOUS_FEEDRATE_THRESHOLD = 0.0001f;
+        const bool has_prev_move = !blocks.empty() && prev.feedrate > PREVIOUS_FEEDRATE_THRESHOLD;
 
-        for (unsigned char a = X; a <= E; ++a) {
-            float axis_max_jerk = get_axis_max_jerk(static_cast<PrintEstimatedStatistics::ETimeMode>(i), static_cast<Axis>(a));
-            if (curr.abs_axis_feedrate[a] > axis_max_jerk)
-                curr.safe_feedrate = std::min(curr.safe_feedrate, axis_max_jerk);
+        // Orca: junction deviation where the firmware uses it (Klipper always, Marlin 2 with M205 J).
+        // Negative leaves the classic jerk path below unchanged.
+        const float vmax_junction_jd = calc_vmax_junction_deviation(block, prev, curr, has_prev_move,
+                                                                    static_cast<PrintEstimatedStatistics::ETimeMode>(i));
+        const bool use_junction_deviation = vmax_junction_jd >= 0.0f;
+
+        // calculates block exit feedrate. Junction deviation has no per axis jerk floor, so a move is
+        // free to start from rest.
+        curr.safe_feedrate = use_junction_deviation ? 0.0f : block.feedrate_profile.cruise;
+
+        if (!use_junction_deviation) {
+            for (unsigned char a = X; a <= E; ++a) {
+                float axis_max_jerk = get_axis_max_jerk(static_cast<PrintEstimatedStatistics::ETimeMode>(i), static_cast<Axis>(a));
+                if (curr.abs_axis_feedrate[a] > axis_max_jerk)
+                    curr.safe_feedrate = std::min(curr.safe_feedrate, axis_max_jerk);
+            }
         }
 
         block.feedrate_profile.exit = curr.safe_feedrate;
 
-        static const float PREVIOUS_FEEDRATE_THRESHOLD = 0.0001f;
-
         // calculates block entry feedrate
-        float vmax_junction = curr.safe_feedrate;
-        if (!blocks.empty() && prev.feedrate > PREVIOUS_FEEDRATE_THRESHOLD) {
+        float vmax_junction = use_junction_deviation ? vmax_junction_jd : curr.safe_feedrate;
+        if (!use_junction_deviation && has_prev_move) {
             bool prev_speed_larger = prev.feedrate > block.feedrate_profile.cruise;
             float smaller_speed_factor = prev_speed_larger ? (block.feedrate_profile.cruise / prev.feedrate) : (prev.feedrate / block.feedrate_profile.cruise);
             // Pick the smaller of the nominal speeds. Higher speed shall not be achieved at the junction during coasting.
@@ -5997,8 +6026,11 @@ void GCodeProcessor::process_G10(const GCodeReader::GCodeLine& line)
     GCodeReader::GCodeLine g10;
     g10.set(Axis::E, -this->m_parser.config().retraction_length.get_at(m_extruder_id));
     g10.set(Axis::F,  this->m_parser.config().retraction_speed.get_at(m_extruder_id) * 60);
+    //Orca: Firmware retract emulation must not change the modal G1 feedrate.
+    const float feedrate = m_feedrate;
     --m_g1_line_id;
     process_G1(g10);
+    m_feedrate = feedrate;
 }
 
 void GCodeProcessor::process_G11(const GCodeReader::GCodeLine& line)
@@ -6007,8 +6039,11 @@ void GCodeProcessor::process_G11(const GCodeReader::GCodeLine& line)
     GCodeReader::GCodeLine g11;
     g11.set(Axis::E, this->m_parser.config().retraction_length.get_at(m_extruder_id) + this->m_parser.config().retract_restart_extra.get_at(m_extruder_id));
     g11.set(Axis::F, this->m_parser.config().deretraction_speed.get_at(m_extruder_id) * 60);
+    // Orca: Firmware unretract emulation must not change the modal G1 feedrate.
+    const float feedrate = m_feedrate;
     --m_g1_line_id;
     process_G1(g11);
+    m_feedrate = feedrate;
 }
 
 void GCodeProcessor::process_G20(const GCodeReader::GCodeLine& line)
@@ -7256,6 +7291,91 @@ float GCodeProcessor::get_axis_max_jerk_with_jd(PrintEstimatedStatistics::ETimeM
     return get_axis_max_jerk_with_jd(mode, axis, get_acceleration(mode));
 }
 
+float GCodeProcessor::get_junction_deviation(PrintEstimatedStatistics::ETimeMode mode, float acceleration) const
+{
+    const size_t id = static_cast<size_t>(mode);
+
+    // Klipper has no classic jerk: jd = scv^2 * (sqrt(2) - 1) / max_accel
+    // (toolhead.py::_calc_junction_deviation). Passing the block acceleration back in makes it cancel
+    // in calc_vmax_junction_deviation(), leaving the identity v == scv at a 90 degree corner.
+    if (m_flavor == gcfKlipper) {
+        // machine_max_jerk_x holds the square corner velocity; process_SET_VELOCITY_LIMIT() writes it.
+        const float scv = get_option_value(m_time_processor.machine_limits.machine_max_jerk_x, id);
+        if (scv <= 0.0f || acceleration <= 0.0f)
+            return 0.0f;
+        return sqr(scv) * (std::sqrt(2.0f) - 1.0f) / acceleration;
+    }
+
+    // Marlin 2 plans with junction deviation only when M205 J > 0; classic jerk leaves it at 0.
+    if (m_flavor == gcfMarlinFirmware)
+        return get_option_value(m_time_processor.machine_limits.machine_max_junction_deviation, id);
+
+    return 0.0f;
+}
+
+float GCodeProcessor::calc_junction_acceleration(const TimeBlock& block, const Vec4f& junction_unit_vec,
+                                                 PrintEstimatedStatistics::ETimeMode mode) const
+{
+    float junction_acceleration = block.acceleration;
+    for (unsigned char a = X; a <= E; ++a) {
+        if (junction_unit_vec[a] == 0.0f)
+            continue;
+        const float axis_max_acceleration = get_axis_max_acceleration(mode, static_cast<Axis>(a), m_machine_config_idx);
+        if (axis_max_acceleration > 0.0f)
+            junction_acceleration = std::min(junction_acceleration, std::abs(axis_max_acceleration / junction_unit_vec[a]));
+    }
+    return junction_acceleration;
+}
+
+// Ported from PrusaSlicer (src/libslic3r/GCode/GCodeProcessor.cpp).
+float GCodeProcessor::calc_vmax_junction_deviation(const TimeBlock& block, const TimeMachine::State& prev,
+                                                   const TimeMachine::State& curr, bool has_prev_move,
+                                                   PrintEstimatedStatistics::ETimeMode mode) const
+{
+    const float junction_deviation = get_junction_deviation(mode, block.acceleration);
+    if (junction_deviation <= 0.0f)
+        return -1.0f; // classic jerk machine, the caller keeps its own computation
+    if (!has_prev_move)
+        return 0.0f;  // starts from rest, the planner raises this on the reverse pass
+
+    // -1 for a straight continuation, +1 for a full reversal. Half angle identity, no acos()/sin().
+    // Both vectors are unit length over XYZE, so this really is a cosine: scaling by 1 / distance
+    // instead, as PrusaSlicer does, leaves an E term that makes extruding corners look straighter
+    // than they are. Marlin normalizes over XYZE for any extruding move (planner.cpp, esteps > 0)
+    // and Klipper keeps E out of the cosine entirely (toolhead.py::Move.calc_junction); both agree
+    // that the corner is planned by its geometry, and normalizing matches them to within 1e-5.
+    float junction_cos_theta = (-prev.jd_unit_vec).dot(curr.jd_unit_vec);
+    if (junction_cos_theta > 0.999999f)
+        return 0.0f; // the path doubles back, the machine has to stop
+    junction_cos_theta = std::max(junction_cos_theta, -0.999999f); // guards the division below
+
+    const float sin_theta_d2 = std::sqrt(0.5f * (1.0f - junction_cos_theta)); // always positive
+    const Vec4f junction_vec = curr.jd_unit_vec - prev.jd_unit_vec;
+    const float junction_vec_norm = junction_vec.norm();
+    const Vec4f junction_unit_vec = (junction_vec_norm > 0.0f) ? Vec4f(junction_vec / junction_vec_norm)
+                                                               : Vec4f(0.0f, 0.0f, 0.0f, 0.0f);
+    const float junction_acceleration = calc_junction_acceleration(block, junction_unit_vec, mode);
+
+    float vmax_junction_sqr = (junction_acceleration * junction_deviation * sin_theta_d2) / (1.0f - sin_theta_d2);
+
+    // Marlin's JD_HANDLE_SMALL_SEGMENTS: a short move through a shallow corner is treated as an arc and
+    // capped by the centripetal acceleration it needs. Klipper has no equivalent.
+    if (m_flavor != gcfKlipper && block.distance < 1.0f && junction_cos_theta < -0.7071067812f) {
+        // Fast acos(-t), max. error +-0.033rad. MinMax polynomial by W. Randolph Franklin:
+        // https://wrf.ecse.rpi.edu/Research/Short_Notes/arcsin/onlyelem.html
+        const float neg = junction_cos_theta < 0.0f ? -1.0f : 1.0f;
+        const float t = neg * junction_cos_theta;
+        const float asinx = 0.032843707f + t * (-1.451838349f + t * (29.66153956f + t * (-131.1123477f +
+                            t * (262.8130562f + t * (-242.7199627f + t * (84.31466202f))))));
+        const float junction_theta = float(0.5 * M_PI) + neg * asinx; // acos(-t), bottoms out at 0.033
+        vmax_junction_sqr = std::min(vmax_junction_sqr, (block.distance * junction_acceleration) / junction_theta);
+    }
+
+    // Never faster than either of the two moves the junction joins.
+    vmax_junction_sqr = std::min(vmax_junction_sqr, std::min(sqr(block.feedrate_profile.cruise), sqr(prev.feedrate)));
+    return std::sqrt(vmax_junction_sqr);
+}
+
 float GCodeProcessor::get_axis_max_jerk(PrintEstimatedStatistics::ETimeMode mode, Axis axis) const
 {
     const size_t id = static_cast<size_t>(mode);

src/libslic3r/GCode/GCodeProcessor.hpp

@@ -660,6 +660,9 @@ class Print;
                 //For line move, there are same. For arc move, there are different.
                 Vec3f enter_direction;
                 Vec3f exit_direction;
+                // Orca: move direction over all four axes, unit length. Used by
+                // calc_vmax_junction_deviation(); see there for why E is normalized in.
+                Vec4f jd_unit_vec;
 
                 void reset();
             };
@@ -1517,6 +1520,16 @@ class Print;
         float get_axis_max_acceleration(PrintEstimatedStatistics::ETimeMode mode, Axis axis, int machine_idx) const;
         float get_axis_max_jerk_with_jd(PrintEstimatedStatistics::ETimeMode mode, Axis axis, float acceleration) const;
         float get_axis_max_jerk_with_jd(PrintEstimatedStatistics::ETimeMode mode, Axis axis) const;
+        // Orca: junction deviation for a block at the given acceleration, 0 for a classic jerk machine.
+        float get_junction_deviation(PrintEstimatedStatistics::ETimeMode mode, float acceleration) const;
+        // Orca: acceleration along the junction direction, clamped by the per axis limits.
+        float calc_junction_acceleration(const TimeBlock& block, const Vec4f& junction_unit_vec,
+                                         PrintEstimatedStatistics::ETimeMode mode) const;
+        // Orca: entry speed from the junction deviation model, which limits a corner by its angle alone
+        // and is therefore isotropic, unlike per axis jerk. Negative means classic jerk applies instead.
+        float calc_vmax_junction_deviation(const TimeBlock& block, const TimeMachine::State& prev,
+                                           const TimeMachine::State& curr, bool has_prev_move,
+                                           PrintEstimatedStatistics::ETimeMode mode) const;
         float get_axis_max_jerk(PrintEstimatedStatistics::ETimeMode mode, Axis axis) const;
         Vec3f get_xyz_max_jerk(PrintEstimatedStatistics::ETimeMode mode) const;
         float get_retract_acceleration(PrintEstimatedStatistics::ETimeMode mode) const;

src/libslic3r/GCode/ThumbnailData.hpp

@@ -32,7 +32,7 @@ using ThumbnailsList = std::vector<ThumbnailData>;
 
 struct ThumbnailsParams
 {
-	const Vec2ds 	sizes;
+	const Vec2ds 	sizes{};
 	bool 			printable_only;
 	bool 			parts_only;
 	bool 			show_bed;

src/libslic3r/GCode/WipeTower.cpp

@@ -617,6 +617,18 @@ Polygon generate_rectange_polygon(const Vec2f &wt_box_min ,const Vec2f & wt_box_
     return res;
 }
 
+const char* flush_planner_queue_command(GCodeFlavor flavor)
+{
+    return flavor == gcfKlipper ? "M400\n" : "G4 S0\n";
+}
+
+std::string wait_command(GCodeFlavor flavor, float seconds)
+{
+    if (flavor == gcfKlipper)
+        return "G4 P" + std::to_string(std::lround(seconds * 1000.f)) + "\n";
+    return "G4 S" + Slic3r::float_to_string_decimal_point(seconds, 3) + "\n";
+}
+
 class WipeTowerWriter
 {
 public:
@@ -1145,7 +1157,7 @@ public:
 	{
         if (time==0.f)
             return *this;
-        m_gcode += "G4 S" + Slic3r::float_to_string_decimal_point(time, 3) + "\n";
+        m_gcode += wait_command(m_gcode_flavor, time);
 		return *this;
     }
 
@@ -1190,7 +1202,7 @@ public:
 
 	WipeTowerWriter& flush_planner_queue()
 	{
-		m_gcode += "G4 S0\n";
+		m_gcode += flush_planner_queue_command(m_gcode_flavor);
 		return *this;
 	}
 
@@ -1333,6 +1345,8 @@ public:
     {
         std::string buffer;
         if (wait_for_moves)
+            // Not flush_planner_queue_command(): this BBL precool path wants M400, which every
+            // flavor it reaches understands, not the zero dwell the other flavors flush with.
             buffer += "M400\n";
         buffer += "M104";
         if (target_extruder != -1)
@@ -1616,25 +1630,56 @@ float WipeTower::get_auto_brim_by_height(float max_height) {
     return 8.f;
 }
 
-Vec2f WipeTower::move_box_inside_box(const BoundingBox &box1, const BoundingBox &box2,int scaled_offset)
+Vec2f WipeTower::move_box_inside_polygon(const BoundingBox &box, const Polygons &polygons, coord_t offset)
 {
-    Vec2f res{0, 0};
-    if (box1.size()[0] >= box2.size()[0]- 2*scaled_offset || box1.size()[1] >= box2.size()[1]-2*scaled_offset) return res;
+    if (polygons.empty()) return Vec2f{0.f, 0.f};
 
-    if (box1.max[0] > box2.max[0] - scaled_offset) {
-        res[0] = unscaled<float>((box2.max[0] - scaled_offset) - box1.max[0]);
-    }
-    else if (box1.min[0] < box2.min[0] + scaled_offset) {
-        res[0] = unscaled<float>((box2.min[0] + scaled_offset) - box1.min[0]);
+    const BoundingBox bed = get_extents(polygons);
+    // No position fits the footprint.
+    if (box.size().x() >= bed.size().x() - 2 * offset || box.size().y() >= bed.size().y() - 2 * offset)
+        return Vec2f{0.f, 0.f};
+
+    // Clamp against the bounding box first, moving only along the axis that is violated so a dragged
+    // prime tower slides along the bed edge instead of jumping inwards.
+    Point shift(0, 0);
+    for (int axis = 0; axis < 2; ++axis) {
+        if (box.max[axis] > bed.max[axis] - offset)
+            shift[axis] = (bed.max[axis] - offset) - box.max[axis];
+        else if (box.min[axis] < bed.min[axis] + offset)
+            shift[axis] = (bed.min[axis] + offset) - box.min[axis];
     }
 
-    if (box1.max[1] > box2.max[1] - scaled_offset) {
-        res[1] = unscaled<float>((box2.max[1] - scaled_offset) - box1.max[1]);
+    // A bed that fills its own bounding box is fully clamped by that, so every rectangular bed — all
+    // but the delta-style profiles — stops here and keeps its historic placement, including when a
+    // negative margin lets the footprint hang over the edge. The tolerance is relative because an
+    // exact rectangle loses a few ulps once the areas are squared world coordinates.
+    double area = 0.;
+    for (const Polygon &poly : polygons) area += std::abs(poly.area());
+    const double bed_area = double(bed.size().x()) * double(bed.size().y());
+    if (area >= bed_area * (1. - EPSILON)) return unscaled<float>(shift);
+
+    // Clamp a negative margin (an auto brim width that has not been resolved yet) to zero: padding by
+    // it would shrink the footprint and hand back a position the validation still rejects. The
+    // epsilon lets the move's round trip through millimeters land on the outline without counting as
+    // a violation.
+    BoundingBox padded = box.inflated(std::max<coord_t>(offset, 0) - SCALED_EPSILON);
+    padded.translate(shift);
+    auto fits = [&padded, &polygons](const Point &move) {
+        BoundingBox moved = padded;
+        moved.translate(move);
+        return diff(Polygons{moved.polygon()}, polygons).empty();
+    };
+    if (fits(Point(0, 0))) return unscaled<float>(shift);
+
+    // Walk towards the middle of the bed. On every non-rectangular bed we ship, the fitting positions
+    // form a convex region around it, so bisecting stops just inside the outline.
+    Point lo(0, 0), hi = bed.center() - padded.center();
+    if (!fits(hi)) return unscaled<float>(shift);
+    for (int i = 0; i < 12; ++i) {
+        const Point mid = (lo + hi) / 2;
+        if (fits(mid)) hi = mid; else lo = mid;
     }
-    else if (box1.min[1] < box2.min[1] + scaled_offset) {
-        res[1] = unscaled<float>((box2.min[1] + scaled_offset) - box1.min[1]);
-    }
-    return res;
+    return unscaled<float>(Point(shift + hi));
 }
 
 Polygon WipeTower::rib_section(float width, float depth, float rib_length, float rib_width,bool fillet_wall)

src/libslic3r/GCode/WipeTower.hpp

@@ -26,6 +26,12 @@ enum GCodeFlavor : unsigned char;
 Polylines construct_gap_for_skip_points(
     const Polygon& polygon, const std::vector<Vec2f>& skip_points, float wt_width, float gap_length, Polygon& insert_skip_polygon);
 
+// Klipper acts on commands the instant it parses them, and its G4 reads only P (milliseconds),
+// so the zero-second and seconds-valued dwells every other flavor uses neither synchronize nor
+// pause there. Both defined in WipeTower.cpp, shared by WipeTower and WipeTower2.
+const char* flush_planner_queue_command(GCodeFlavor flavor); // finish queued moves, e.g. around M104/M109
+std::string wait_command(GCodeFlavor flavor, float seconds);  // pause for `seconds`
+
 class WipeTower
 {
 public:
@@ -39,7 +45,11 @@ public:
     static TriangleMesh                 its_make_rib_tower(float width, float depth, float height, float rib_length, float rib_width, bool fillet_wall);
     static TriangleMesh                 its_make_rib_brim(const Polygon& brim, float layer_height);
     static Polygon                      rib_section(float width, float depth, float rib_length, float rib_width, bool fillet_wall);
-    static Vec2f                        move_box_inside_box(const BoundingBox &box1, const BoundingBox &box2, int offset = 0);
+    // Translation that brings a footprint inside the printable outline, padded by offset. The prime
+    // tower is validated against the real outline (see layered_print_cleareance_valid), so clamping
+    // against the bounding box alone would leave it off a delta or hexagonal bed. box and polygons
+    // must share one scaled coordinate frame; the translation comes back in millimeters.
+    static Vec2f                        move_box_inside_polygon(const BoundingBox &box, const Polygons &polygons, coord_t offset = 0);
     static Polygon                      rounding_polygon(Polygon &polygon, double rounding = 2., double angle_tol = 30. / 180. * PI);
     struct Extrusion
     {

src/libslic3r/GCode/WipeTower2.cpp

@@ -386,7 +386,8 @@ public:
     }
 
     WipeTowerWriter2& switch_filament_monitoring(bool enable) {
-        m_gcode += std::string("G4 S0\n") + "M591 " + (enable ? "R" : "S0") + "\n";
+        flush_planner_queue();
+        m_gcode += enable ? "M591 R\n" : "M591 S0\n";
         return *this;
     }
 
@@ -412,6 +413,7 @@ public:
 	const Vec2f& 		 pos()   const { return m_current_pos; }
 	const Vec2f	 		 start_pos_rotated() const { return m_start_pos; }
 	const Vec2f  		 pos_rotated() const { return this->rotate(m_current_pos); }
+	const Vec2f  		 rotated(const Vec2f &pt) const { return this->rotate(pt); }
 	float 				 elapsed_time() const { return m_elapsed_time; }
     float                get_and_reset_used_filament_length() { float temp = m_used_filament_length; m_used_filament_length = 0.f; return temp; }
 
@@ -623,10 +625,13 @@ public:
 	}
 
 	// Set extruder temperature, don't wait by default.
-	WipeTowerWriter2& set_extruder_temp(int temperature, bool wait = false)
+	WipeTowerWriter2& set_extruder_temp(int temperature, bool wait = false, const std::string& comment = std::string())
 	{
-        m_gcode += "G4 S0\n"; // to flush planner queue
-        m_gcode += "M" + std::to_string(wait ? 109 : 104) + " S" + std::to_string(temperature) + "\n";
+        flush_planner_queue();
+        m_gcode += "M" + std::to_string(wait ? 109 : 104) + " S" + std::to_string(temperature);
+        if (!comment.empty())
+            m_gcode += " " + comment;
+        m_gcode += "\n";
         return *this;
     }
 
@@ -635,7 +640,7 @@ public:
 	{
         if (time==0.f)
             return *this;
-        m_gcode += "G4 S" + Slic3r::float_to_string_decimal_point(time, 3) + "\n";
+        m_gcode += wait_command(m_gcode_flavor, time);
 		return *this;
     }
 
@@ -677,8 +682,8 @@ public:
     }
 
 	WipeTowerWriter2& flush_planner_queue()
-	{ 
-		m_gcode += "G4 S0\n"; 
+	{
+		m_gcode += flush_planner_queue_command(m_gcode_flavor);
 		return *this;
 	}
 
@@ -1005,6 +1010,13 @@ bool WipeTower2::use_gap_wall(const PrintConfig& config)
     return config.prime_tower_skip_points.value && config.wipe_tower_wall_type.value != wtwCone;
 }
 
+bool WipeTower2::wait_for_temp_enabled(const PrintConfig& config)
+{
+    // SEMM runs its own unload/load temperature sequence; the GUI hides the option
+    // there but a profile may still carry it set.
+    return config.wait_for_temp_on_wipe_tower.value && !config.single_extruder_multi_material.value;
+}
+
 WipeTower2::WipeTower2(const PrintConfig& config, const PrintRegionConfig& default_region_config,int plate_idx, Vec3d plate_origin, const std::vector<std::vector<float>>& wiping_matrix, size_t initial_tool) :
     m_semm(config.single_extruder_multi_material.value),
     m_enable_filament_ramming(config.enable_filament_ramming.value),
@@ -1034,7 +1046,8 @@ WipeTower2::WipeTower2(const PrintConfig& config, const PrintRegionConfig& defau
     m_wall_type((int)config.wipe_tower_wall_type),
     m_use_gap_wall(use_gap_wall(config)),
     m_enable_tower_interface_features(config.enable_tower_interface_features.value),
-    m_enable_tower_interface_cooldown_during_tower(config.enable_tower_interface_cooldown_during_tower.value)
+    m_enable_tower_interface_cooldown_during_tower(config.enable_tower_interface_cooldown_during_tower.value),
+    m_wait_for_temp_on_wipe_tower(wait_for_temp_enabled(config))
 {
     // Read absolute value of first layer speed, if given as percentage,
     // it is taken over following default. Speeds from config are not
@@ -1084,6 +1097,7 @@ WipeTower2::WipeTower2(const PrintConfig& config, const PrintRegionConfig& defau
     m_bed_bottom_left = m_bed_shape == RectangularBed
                   ? Vec2f(bed_points.front().x(), bed_points.front().y())
                   : Vec2f::Zero();
+    m_bed_polygon = Polygon::new_scale(bed_points);
 }
 
 
@@ -1235,7 +1249,7 @@ std::vector<WipeTower::ToolChangeResult> WipeTower2::prime(
 
         unsigned int tool = tools[idx_tool];
         m_left_to_right = true;
-        toolchange_Change(writer, tool, m_filpar[tool].material); // Select the tool, set a speed override for soluble and flex materials.
+        toolchange_Change(writer, tool, m_filpar[tool].material, m_filpar[tool].first_layer_temperature, false); // Select the tool, set a speed override for soluble and flex materials.
         toolchange_Load(writer, cleaning_box); // Prime the tool.
         if (idx_tool + 1 == tools.size()) {
             // Last tool should not be unloaded, but it should be wiped enough to become of a pure color.
@@ -1354,13 +1368,19 @@ WipeTower::ToolChangeResult WipeTower2::tool_change(size_t tool)
         toolchange_Unload(writer, cleaning_box, m_filpar[m_current_tool].material,
                           (is_first_layer() ? m_filpar[m_current_tool].first_layer_temperature : m_filpar[m_current_tool].temperature),
                           new_tool_temp);
-        toolchange_Change(writer, tool, m_filpar[tool].material); // Change the tool, set a speed override for soluble and flex materials.
+        // Wait-at-tower target: the interface temp when an interface boost applies on this layer,
+        // otherwise the print temp (nozzle_temperature == 0 means "use the first layer temp").
+        int wait_for_temp = interface_layer && m_filpar[tool].interface_print_temperature > 0 ?
+                                m_filpar[tool].interface_print_temperature :
+                                (is_first_layer() || m_filpar[tool].temperature == 0 ? m_filpar[tool].first_layer_temperature : m_filpar[tool].temperature);
+        toolchange_Change(writer, tool, m_filpar[tool].material, wait_for_temp, true); // Change the tool, set a speed override for soluble and flex materials.
         toolchange_Load(writer, cleaning_box);
         writer.travel(writer.x(), writer.y()-m_perimeter_width); // cooling and loading were done a bit down the road
         int base_temp = is_first_layer() ? m_filpar[tool].first_layer_temperature : m_filpar[tool].temperature;
         if (interface_layer) {
             int interface_temp = m_filpar[tool].interface_print_temperature;
-            if (interface_temp > 0 && interface_temp != base_temp)
+            // With wait-for-temp-on-wipe-tower the toolchange already blocked for the interface temp.
+            if (interface_temp > 0 && interface_temp != base_temp && !m_wait_for_temp_on_wipe_tower)
                 writer.set_extruder_temp(interface_temp, true);
             if (m_enable_tower_interface_cooldown_during_tower && interface_temp > 0 && interface_temp != base_temp)
                 writer.set_extruder_temp(base_temp, false);
@@ -1670,7 +1690,9 @@ void WipeTower2::toolchange_Unload(
 void WipeTower2::toolchange_Change(
 	WipeTowerWriter2 &writer,
     const size_t 	new_tool,
-    const std::string&  new_material)
+    const std::string&  new_material,
+    const int       wait_for_temp,
+    const bool      wait_beside_tower)
 {
     // Ask the writer about how much of the old filament we consumed:
     if (m_current_tool < m_used_filament_length.size())
@@ -1684,6 +1706,90 @@ void WipeTower2::toolchange_Change(
     if (m_is_mk4mmu3)
         writer.switch_filament_monitoring(true);
 
+    const bool wait_for_temp_here = m_wait_for_temp_on_wipe_tower && wait_for_temp > 0;
+
+    // The Tn above was issued without a blocking temperature wait (GCode::set_extruder only raises
+    // the target, ahead of the Tn); block here, before the deretraction below, which must not
+    // extrude on a cold nozzle. Like the Bambu H2C, park beside the tower for the heat-up so drool lands
+    // next to it instead of on its top surface — nearest x side first, then that side clamped
+    // toward the bed edge, then the far side, in place if all would leave the bed. Raw
+    // pre-rotated moves (see the repositioning move below) keep the writer's tracked position
+    // at the tower entry. The tag keeps the
+    // interface-temp deduplication pass in append_tcr2 from stripping the M109.
+    if (wait_for_temp_here && wait_beside_tower) {
+        // The rib wall and the stabilization cone bulge past the nominal width rectangle
+        // (widest near the bottom), and the first-layer brim is printed around the wall later
+        // in the layer — clear the widest of them, not just the rectangle, so the park point
+        // and its drool stay off the tower.
+        float min_x = 0.f, max_x = m_wipe_tower_width;
+        if (m_wall_type == (int)wtwRib) {
+            WipeTower::box_coordinates wt_box(Vec2f(0.f, 0.f), m_wipe_tower_width, m_layer_info->depth + m_perimeter_width);
+            const BoundingBox rib_bbox = get_extents(generate_rib_polygon(wt_box)); // the fillet stays within this bbox
+            min_x = std::min(min_x, unscaled<float>(rib_bbox.min.x()));
+            max_x = std::max(max_x, unscaled<float>(rib_bbox.max.x()));
+        } else if (m_wall_type == (int)wtwCone) {
+            const double support_scale = get_wipe_tower_cone_base(m_wipe_tower_width, m_wipe_tower_height, m_wipe_tower_depth,
+                                                                  m_wipe_tower_cone_angle).second;
+            const double z = m_no_sparse_layers ? (m_current_height + m_layer_info->height) : m_layer_info->z;
+            const double r = std::tan(Geometry::deg2rad(m_wipe_tower_cone_angle / 2.f)) * (m_wipe_tower_height - z);
+            const double w = m_layer_info->depth + m_perimeter_width;
+            if (r > 0.5 * w + 0.01) { // same guard as generate_support_cone_wall
+                const float bulge = float(std::sqrt(r * r - 0.25 * w * w) / support_scale);
+                min_x = std::min(min_x, m_wipe_tower_width / 2.f - bulge);
+                max_x = std::max(max_x, m_wipe_tower_width / 2.f + bulge);
+            }
+        }
+        if (is_first_layer()) {
+            const float brim = m_wipe_tower_brim_width < 0.f ? WipeTower::get_auto_brim_by_height(m_wipe_tower_height) :
+                                                               m_wipe_tower_brim_width;
+            min_x -= brim;
+            max_x += brim;
+        }
+        constexpr float gap     = 2.f;
+        constexpr float min_gap = 0.5f;
+        const bool      on_left = writer.x() < m_wipe_tower_width / 2.f;
+        const float     near_x  = on_left ? min_x - gap : max_x + gap;
+        const float     far_x   = on_left ? max_x + gap : min_x - gap;
+        const Eigen::Rotation2Df to_bed(float(Geometry::deg2rad(m_wipe_tower_rotation_angle)));
+        auto park_pt_on_bed = [this, &writer, to_bed](float side_x) {
+            const Vec2f bed_pt = to_bed * (writer.rotated(Vec2f(side_x, writer.y())) + m_rib_offset) + m_wipe_tower_pos;
+            return m_bed_polygon.contains(Point::new_scale(bed_pt.x(), bed_pt.y()));
+        };
+        float park_x    = near_x;
+        bool  have_park = park_pt_on_bed(near_x);
+        if (!have_park) {
+            // The ideal near point hangs off the bed: pull it back to the bed edge as long
+            // as that still clears the tower envelope by min_gap (the BBL tower clamps its
+            // stop_pos against the bed the same way in append_tcr). Bisection, because with
+            // tower rotation and non-rectangular beds the bed edge is not axis-aligned.
+            const float limit_x = on_left ? min_x - min_gap : max_x + min_gap;
+            if (park_pt_on_bed(limit_x)) {
+                float on = limit_x, off = near_x;
+                for (int i = 0; i < 8; ++i) {
+                    const float mid = 0.5f * (on + off);
+                    if (park_pt_on_bed(mid))
+                        on = mid;
+                    else
+                        off = mid;
+                }
+                park_x    = on;
+                have_park = true;
+            }
+        }
+        if (!have_park && park_pt_on_bed(far_x)) {
+            park_x    = far_x;
+            have_park = true;
+        }
+        if (have_park) {
+            const Vec2f stop = writer.rotated(Vec2f(park_x, writer.y()));
+            writer.feedrate(m_travel_speed * 60.f)
+                  .append(std::string("G1 X") + Slic3r::float_to_string_decimal_point(stop.x())
+                                     +  " Y"  + Slic3r::float_to_string_decimal_point(stop.y())
+                                     + never_skip_tag() + "\n");
+        }
+        writer.set_extruder_temp(wait_for_temp, true, wait_for_temp_tag());
+    }
+
     // Travel to where we assume we are. Custom toolchange or some special T code handling (parking extruder etc)
     // gcode could have left the extruder somewhere, we cannot just start extruding. We should also inform the
     // postprocessor that we absolutely want to have this in the gcode, even if it thought it is the same as before.
@@ -1694,6 +1800,10 @@ void WipeTower2::toolchange_Change(
                              + never_skip_tag() + "\n"
     );
 
+    // Priming has no tower to park beside — wait right at the priming line instead.
+    if (wait_for_temp_here && !wait_beside_tower)
+        writer.set_extruder_temp(wait_for_temp, true, wait_for_temp_tag());
+
     writer.append("[deretraction_from_wipe_tower_generator]");
 
     // The toolchange Tn command will be inserted later, only in case that the user does
@@ -2020,31 +2130,68 @@ std::pair<double, double> WipeTower2::get_wipe_tower_cone_base(double width, dou
 }
 
 // Static method to extract wipe_volumes[from][to] from the configuration.
-std::vector<std::vector<float>> WipeTower2::extract_wipe_volumes(const PrintConfig& config)
+// Takes a ConfigBase so the GUI's wipe tower size estimate can pass the plate's
+// DynamicPrintConfig directly instead of materializing a full PrintConfig per call.
+std::vector<std::vector<float>> WipeTower2::extract_wipe_volumes(const ConfigBase& config)
 {
-    // Get wiping matrix to get number of extruders and convert vector<double> to vector<float>:
-    std::vector<float> wiping_matrix(cast<float>(config.flush_volumes_matrix.values));
-    auto scale = config.flush_multiplier.get_at(0);
+    // flush_volumes_matrix holds one filaments x filaments block per nozzle (written by
+    // PresetBundle::update_multi_material_filament_presets), so the filament count is
+    // sqrt(size / nozzles). One tower serves every nozzle and the filament to nozzle assignment is
+    // only decided later by ToolOrdering, so fold the blocks with std::max: the depth reserved here
+    // has to cover the worst nozzle. With a single nozzle the fold has one term.
+    const std::vector<double> &raw_matrix      = config.option<ConfigOptionFloats>("flush_volumes_matrix")->values;
+    const auto                *nozzle_diameter = config.option<ConfigOptionFloats>("nozzle_diameter");
+    size_t       nozzle_nums         = (nozzle_diameter == nullptr || nozzle_diameter->values.empty()) ? 1 : nozzle_diameter->values.size();
+    unsigned int number_of_extruders = (unsigned int)(sqrt(raw_matrix.size() / nozzle_nums) + EPSILON);
+    if (size_t(number_of_extruders) * number_of_extruders * nozzle_nums != raw_matrix.size()) {
+        // Saved for a different nozzle count (older project, or the printer was just switched):
+        // fall back to reading the whole option as one block, as this did before.
+        nozzle_nums         = 1;
+        number_of_extruders = (unsigned int)(sqrt(raw_matrix.size()) + EPSILON);
+    }
 
     // The values shall only be used when SEMM is enabled. The purging for other printers
     // is determined by filament_minimal_purge_on_wipe_tower.
-    if (! config.purge_in_prime_tower.value || ! config.single_extruder_multi_material.value)
-        std::fill(wiping_matrix.begin(), wiping_matrix.end(), 0.f);
+    const bool purge = config.option<ConfigOptionBool>("purge_in_prime_tower")->value
+                    && config.option<ConfigOptionBool>("single_extruder_multi_material")->value;
 
-    // Extract purging volumes for each extruder pair:
-    std::vector<std::vector<float>> wipe_volumes;
-    const unsigned int number_of_extruders = (unsigned int)(sqrt(wiping_matrix.size())+EPSILON);
-    for (size_t i = 0; i<number_of_extruders; ++i)
-        wipe_volumes.push_back(std::vector<float>(wiping_matrix.begin()+i*number_of_extruders, wiping_matrix.begin()+(i+1)*number_of_extruders));
+    // Extract purging volumes for each extruder pair, each nozzle's block scaled by its own multiplier:
+    std::vector<std::vector<float>> wipe_volumes(number_of_extruders, std::vector<float>(number_of_extruders, 0.f));
+    if (purge) {
+        const auto *multiplier = config.option<ConfigOptionFloats>("flush_multiplier");
+        for (size_t nozzle_id = 0; nozzle_id < nozzle_nums; ++nozzle_id) {
+            const std::vector<double> block = get_flush_volumes_matrix(raw_matrix, nozzle_id, nozzle_nums);
+            const double              scale = multiplier->get_at(nozzle_id);
+            for (unsigned int i = 0; i<number_of_extruders; ++i)
+                for (unsigned int j = 0; j<number_of_extruders; ++j)
+                    wipe_volumes[i][j] = std::max<float>(wipe_volumes[i][j], float(block[size_t(i) * number_of_extruders + j]) * scale);
+        }
+    }
 
     // Also include filament_minimal_purge_on_wipe_tower. This is needed for the preview.
+    const auto *minimal_purge = config.option<ConfigOptionFloats>("filament_minimal_purge_on_wipe_tower");
     for (unsigned int i = 0; i<number_of_extruders; ++i)
         for (unsigned int j = 0; j<number_of_extruders; ++j)
-            wipe_volumes[i][j] = std::max<float>(wipe_volumes[i][j] * scale, config.filament_minimal_purge_on_wipe_tower.get_at(j));
+            wipe_volumes[i][j] = std::max<float>(wipe_volumes[i][j], minimal_purge->get_at(j));
 
     return wipe_volumes;
 }
 
+float WipeTower2::estimate_semm_flush_volume(const ConfigBase& config, size_t filaments_cnt)
+{
+    const std::vector<std::vector<float>> wipe_volumes = extract_wipe_volumes(config);
+    if (wipe_volumes.empty()) // an empty flush matrix would make the average below 0/0
+        return 0.f;
+    float maximum = 0.f;
+    for (const std::vector<float> &v : wipe_volumes)
+        maximum += *std::max_element(v.begin(), v.end());
+    maximum = maximum * filaments_cnt / wipe_volumes.size();
+
+    // Orca: it's overshooting a bit, so let's reduce it a bit
+    maximum *= 0.6;
+    return maximum;
+}
+
 static float get_wipe_depth(float volume, float layer_height, float perimeter_width, float extra_flow, float extra_spacing, float width)
 {
     float length_to_extrude = (volume_to_length(volume, perimeter_width, layer_height)) / extra_flow;

src/libslic3r/GCode/WipeTower2.hpp

@@ -17,13 +17,20 @@ namespace Slic3r
 
 class WipeTowerWriter2;
 class PrintRegionConfig;
+class ConfigBase;
 
 class WipeTower2
 {
 public:
     static const std::string never_skip_tag() { return "_GCODE_WIPE_TOWER_NEVER_SKIP_TAG"; }
+    // Marks the wait-for-temp-on-wipe-tower M109 so the interface-temp deduplication pass
+    // in WipeTowerIntegration::append_tcr2 does not strip it.
+    static const std::string wait_for_temp_tag() { return ";_WAIT_FOR_TEMP_ON_WIPE_TOWER"; }
 	static std::pair<double, double> get_wipe_tower_cone_base(double width, double height, double depth, double angle_deg);
-	static std::vector<std::vector<float>> extract_wipe_volumes(const PrintConfig& config);
+	static std::vector<std::vector<float>> extract_wipe_volumes(const ConfigBase& config);
+	// Estimated total flush volume of a SEMM print with the given number of filaments,
+	// used to reserve wipe tower space before the tower is generated.
+	static float estimate_semm_flush_volume(const ConfigBase& config, size_t filaments_cnt);
 
     
     // Construct ToolChangeResult from current state of WipeTower2 and WipeTowerWriter2.
@@ -38,6 +45,11 @@ public:
     // Shared with the entry routing in GCode.cpp so the router and the tower agree.
     static bool use_gap_wall(const PrintConfig& config);
 
+    // Whether the blocking toolchange temperature wait moves onto the wipe tower.
+    // Shared with the defer flag in GCode.cpp append_tcr2 so the deferral and the
+    // tower's tagged M109 can never disagree.
+    static bool wait_for_temp_enabled(const PrintConfig& config);
+
 	// x			-- x coordinates of wipe tower in mm ( left bottom corner )
 	// y			-- y coordinates of wipe tower in mm ( left bottom corner )
 	// width		-- width of wipe tower in mm ( default 60 mm - leave as it is )
@@ -227,6 +239,7 @@ private:
     size_t m_first_layer_idx    = size_t(-1);
     bool   m_enable_tower_interface_features = false;
     bool   m_enable_tower_interface_cooldown_during_tower = false;
+    bool   m_wait_for_temp_on_wipe_tower = false;
     bool   m_prev_layer_had_interface = false;
     bool   m_current_layer_has_interface = false;
 
@@ -263,6 +276,7 @@ private:
     } m_bed_shape;
     float m_bed_width; // width of the bed bounding box
     Vec2f m_bed_bottom_left; // bottom-left corner coordinates (for rectangular beds)
+    Polygon m_bed_polygon; // printable_area contour (scaled)
 
 	float m_perimeter_width = 0.4f * Width_To_Nozzle_Ratio; // Width of an extrusion line, also a perimeter spacing for 100% infill.
 	float m_extrusion_flow = 0.038f; //0.029f;// Extrusion flow is derived from m_perimeter_width, layer height and filament diameter.
@@ -385,7 +399,9 @@ private:
 	void toolchange_Change(
 		WipeTowerWriter2 &writer,
         const size_t		new_tool,
-		const std::string& 		new_material);
+		const std::string& 		new_material,
+		const int 				wait_for_temp,
+		const bool 				wait_beside_tower);
 	
 	void toolchange_Load(
 		WipeTowerWriter2 &writer,

src/libslic3r/GCodeWriter.cpp

@@ -4,6 +4,7 @@
 #include "I18N.hpp"
 #include "PrintConfig.hpp"
 #include "ClipperUtils.hpp"
+#include "Geometry/ArcWelder.hpp"
 #include "Line.hpp"
 #include <algorithm>
 #include <iomanip>
@@ -1086,45 +1087,48 @@ std::string GCodeWriter::_spiral_travel_to_z(double z, const Vec2d &ij_offset, c
     }
 
     if (!this->config.enable_arc_fitting) { // Orca: if arc fitting is disabled, approximate the arc with small linear segments
-        std::ostringstream oss;
         const double z_start = m_pos(2); // starting Z height
 
-        // --------------------------------------------------------------------
-        // Determine number of segments based on Resolution
-        // --------------------------------------------------------------------
-        const double ref_resolution = 0.01; // reference resolution in mm
-        const double ref_segments  = 8.0;  // reference number of segments at reference resolution
-        
-        // number of linear segments to use for approximating the arc, clamp between 4 and 16
-        const int segments = std::clamp(int(std::round(ref_segments * (ref_resolution / m_resolution))), 4, 16);
-        // --------------------------------------------------------------------
-
         const double px = m_pos(0) - m_x_offset;        // take plate offset into consideration
         const double py = m_pos(1) - m_y_offset;        // take plate offset into consideration
         const double cx = px + ij_offset(0);            // center x
         const double cy = py + ij_offset(1);            // center y
         const double radius = ij_offset.norm();         // radius
+
+        // Number of linear segments approximating the circle, chosen so that a chord never deviates
+        // from the true arc by more than the slicing resolution. A resolution of 0 means "no
+        // simplification", which has no finite segment count, so it takes the upper bound.
+        constexpr size_t min_segments = 8;              // keep a small spiral visibly round
+        constexpr size_t max_segments = 128;            // bound the emitted G-code
+        const int segments = int(m_resolution > 0. ?
+            std::clamp(Geometry::ArcWelder::arc_discretization_steps(radius, 2. * M_PI, m_resolution), min_segments, max_segments) :
+            max_segments);
+
         const double a0 = std::atan2(py - cy, px - cx); // start angle
-        const double delta = 2.0 * M_PI;                // CCW full circle
 
-        if (full_gcode_comment)
-            oss << ";" << comment << "\n";
+        auto emit_point = [&output](const Vec3d &point) {
+            GCodeG1Formatter w;
+            w.emit_xyz(point);
+            output += w.string();
+        };
 
-        oss << "G1 F" << (speed * 60.0) << "\n";  // set feedrate
+        output.reserve(size_t(segments) * 40);          // ~40 characters per emitted G1 line
+
+        GCodeG1Formatter w;                             // set feedrate
+        w.emit_f(speed * 60.0);
+        w.emit_comment(GCodeWriter::full_gcode_comment, comment);
+        output += w.string();
 
         // approximate the arc with small linear segments (without the last point which is added later to ensure exactness)
         for (int i = 1; i < segments; ++i) {
-            double t = double(i) / segments;            // parametric position along arc
-            double a = a0 + delta * t;                  // CCW arc param
-            double x = cx + radius * std::cos(a);       // point on circle
-            double y = cy + radius * std::sin(a);       // point on circle
-            double zz = z_start + (z - z_start) * t;    // interpolated Z height
-
-            oss << "G1 X" << x << " Y" << y << " Z" << zz << "\n";
+            const double t = double(i) / segments;      // parametric position along arc
+            const double a = a0 + 2. * M_PI * t;        // CCW arc param, full circle
+            emit_point(Vec3d(cx + radius * std::cos(a), // point on circle
+                             cy + radius * std::sin(a),
+                             z_start + (z - z_start) * t)); // interpolated Z height
         }
 
-        oss << "G1 X" << px << " Y" << py << " Z" << z << "\n";  // final point to ensure exactness
-        output = oss.str();
+        emit_point(Vec3d(px, py, z));                   // final point to ensure exactness
     } else { // Orca: if arc fitting is enabled emit a G2/G3 command for the spiral lift
         output = std::string("G17") + (full_gcode_comment ? " ; XY plane for arc\n" : "\n");
 

src/libslic3r/Measure.hpp

@@ -94,7 +94,7 @@ public:
 
     void* volume{nullptr};
     std::vector<int>*    plane_indices{nullptr};
-    Transform3d                  world_tran;
+    Transform3d                  world_tran = Transform3d::Identity();
     std::shared_ptr<std::vector<SurfaceFeature>> world_plane_features{nullptr};
     std::shared_ptr<SurfaceFeature> origin_surface_feature{nullptr};
 

src/libslic3r/Model.cpp

@@ -3243,9 +3243,9 @@ double Model::findMaxSpeed(const ModelObject* object) {
         if (objectKey == "outer_wall_speed")
             externalPerimeterSpeedObj = object->config.get().opt_float_nullable(objectKey, 0);
         if (objectKey == "small_perimeter_speed")
-            smallPerimeterSpeedObj = object->config.get().opt_float_nullable(objectKey, 0);
+            smallPerimeterSpeedObj = object->config.get().opt_float_or_percent_nullable(objectKey, 0).get_abs_value(externalPerimeterSpeedObj);
         if (objectKey == "small_support_perimeter_speed")
-            smallSupportPerimeterSpeedObj = object->config.get().opt_float_nullable(objectKey, 0);
+            smallSupportPerimeterSpeedObj = object->config.get().opt_float_or_percent_nullable(objectKey, 0).get_abs_value(supportSpeedObj);
     }
     objMaxSpeed = std::max(perimeterSpeedObj, std::max(externalPerimeterSpeedObj, std::max(infillSpeedObj, std::max(solidInfillSpeedObj, std::max(topSolidInfillSpeedObj, std::max(supportSpeedObj, std::max(smallPerimeterSpeedObj, std::max(smallSupportPerimeterSpeedObj, objMaxSpeed))))))));
     if (objMaxSpeed <= 0) objMaxSpeed = 250.;

src/libslic3r/OpenVDBUtils.cpp

@@ -1,4 +1,6 @@
+#ifndef NOMINMAX
 #define NOMINMAX
+#endif
 #include "OpenVDBUtils.hpp"
 
 #ifdef _MSC_VER

src/libslic3r/Orient.hpp

@@ -48,100 +48,50 @@ struct OrientMesh {
 
 };
 
-// params for minimizing support area
-struct OrientParamsArea {
-    float TAR_A = 0.015f;
-    float TAR_B = 0.177f;
-    float RELATIVE_F = 20;
-    float CONTOUR_F = 0.5f;
-    float BOTTOM_F = 2.5f;
-    float BOTTOM_HULL_F = 0.1f;
-    float TAR_C = 0.1f;
-    float TAR_D = 1;
-    float TAR_E = 0.0115f;
-    float FIRST_LAY_H = 0.2f;//0.0475;
-    float VECTOR_TOL = -0.00083f;
-    float NEGL_FACE_SIZE = 0.01f;
-    float ASCENT = -0.5f;
-    float PLAFOND_ADV = 0.0599f;
-    float CONTOUR_AMOUNT = 0.0182427f;
-    float OV_H = 2.574f;
-    float height_offset = 2.3728f;
-    float height_log = 0.041375f;
-    float height_log_k = 1.9325457f;
-    float LAF_MAX = 0.999f; // cos(1.4\degree) for low angle face 0.9997f
-    float LAF_MIN = 0.97f;  // cos(14\degree) 0.9703f
-    float TAR_LAF = 0.001f; //0.01f
-    float TAR_PROJ_AREA = 0.1f;
-    float BOTTOM_MIN = 0.1f;  // min bottom area. If lower than it the object may be unstable
-    float BOTTOM_MAX = 2000;  // max bottom area. If get to it the object is stable enough (further increase bottom area won't do more help)
-    float height_to_bottom_hull_ratio_MIN = 1;
-    float BOTTOM_HULL_MAX = 2000;// max bottom hull area
-    float APPERANCE_FACE_SUPP=3; // penalty of generating supports on appearance face
-
-    float overhang_angle = 60.f;
-    bool use_low_angle_face = true;
-    bool min_volume = false;
-    Eigen::Vector3f fun_dir;
-
-    /// Allow parallel execution.
-    bool parallel = true;
-
-    /// Progress indicator callback called when an object gets packed.
-    /// The unsigned argument is the number of items remaining to pack.
-    std::function<void(unsigned, std::string)> progressind = {};
-
-    /// A predicate returning true if abort is needed.
-    std::function<bool(void)>     stopcondition = {};
-
-    OrientParamsArea() = default;
-};
-
 struct OrientParams {
-    float TAR_A = 0.01f;//0.128f;
-    float TAR_B = 0.177f;
-    float RELATIVE_F= 6.610621027964314f;
-    float CONTOUR_F = 0.23228623269775997f;
-    float BOTTOM_F = 1.167152017941474f;
-    float BOTTOM_HULL_F = 0.1f;
-    float TAR_C = 0.24308070476924726f;
-    float TAR_D = 0.6284515508160871f;
-    float TAR_E = 0;//0.032157292647062234;
-    float FIRST_LAY_H = 0.2f;//0.029;
-    float VECTOR_TOL = -0.0011163303070972383f;
-    float NEGL_FACE_SIZE = 0.1f;
-    float ASCENT= -0.5f;
-    float PLAFOND_ADV = 0.04079208948120519f;
-    float CONTOUR_AMOUNT = 0.0101472219892684f;
-    float OV_H = 1.0370178217794535f;
-    float height_offset = 2.7417608343142073f;
-    float height_log = 0.06442030687034085f;
-    float height_log_k = 0.3933594673063997f;
-    float LAF_MAX = 0.999f; // cos(1.4\degree) for low angle face //0.9997f;
-    float LAF_MIN= 0.9703f;  // cos(14\degree) 0.9703f;
-    float TAR_LAF = 0.01f; //0.1f
-    float TAR_PROJ_AREA = 0.1f;
-    float BOTTOM_MIN = 0.1f;  // min bottom area. If lower than it the objects may be unstable
-    float BOTTOM_MAX = 2000; //400
-    float height_to_bottom_hull_ratio_MIN = 1;
-    float BOTTOM_HULL_MAX = 2000;// max bottom hull area to clip //600
-    float APPERANCE_FACE_SUPP=3; // penalty of generating supports on appearance face
-
-    float overhang_angle = 60.f;
-    bool use_low_angle_face = true;
-    bool min_volume = false;
-    Eigen::Vector3f fun_dir;
+    float TAR_A               { 0.01f };     // 0.128f;
+    float TAR_B               { 0.177f };
+    float RELATIVE_F          { 6.610621027964314f };
+    float CONTOUR_F           { 0.23228623269775997f };
+    float BOTTOM_F            { 1.167152017941474f };
+    float BOTTOM_HULL_F       { 0.1f };
+    float TAR_C               { 0.24308070476924726f };
+    float TAR_D               { 0.6284515508160871f };
+    float TAR_E               { 0};         // 0.032157292647062234;
+    float FIRST_LAY_H         { 0.2f};      // 0.029;
+    float VECTOR_TOL          { -0.0011163303070972383f };
+    float NEGL_FACE_SIZE      { 0.1f };
+    float ASCENT              { -0.5f };
+    float PLAFOND_ADV         { 0.04079208948120519f };
+    float CONTOUR_AMOUNT      { 0.0101472219892684f };
+    float OV_H                { 1.0370178217794535f };
+    float height_offset       { 2.7417608343142073f };
+    float height_log          { 0.06442030687034085f };
+    float height_log_k        { 0.3933594673063997f };
+    float LAF_MAX             { 0.999f };    // cos(1.4\degree) for low angle face //0.9997f;
+    float LAF_MIN             { 0.9703f };   // cos(14\degree) 0.9703f;
+    float TAR_LAF             { 0.01f };     // 0.1f
+    float TAR_PROJ_AREA       { 0.1f };
+    float BOTTOM_MIN          { 0.1f };      // min bottom area. If lower than it the objects may be unstable
+    float BOTTOM_MAX          { 2000 };      // 400
+    float height_to_bottom_hull_ratio_MIN { 1 };
+    float BOTTOM_HULL_MAX     { 2000 };      // max bottom hull area to clip //600
+    float APPERANCE_FACE_SUPP { 3 };         // penalty of generating supports on appearance face
 
+    float overhang_angle     { 60.f };
+    bool  use_low_angle_face { true };
+    bool  min_volume         { false };
+    Eigen::Vector3f fun_dir  {};
 
     /// Allow parallel execution.
-    bool parallel = false;
+    bool parallel { false };
 
     /// Progress indicator callback called when an object gets packed.
     /// The unsigned argument is the number of items remaining to pack.
-    std::function<void(unsigned, std::string)> progressind = {};
+    std::function<void(unsigned, std::string)> progressind {};
 
     /// A predicate returning true if abort is needed.
-    std::function<bool(void)>     stopcondition = {};
+    std::function<bool(void)> stopcondition {};
 
     OrientParams() = default;
 };

src/libslic3r/PerimeterGenerator.cpp

@@ -229,6 +229,22 @@ static ExtrusionEntityCollection traverse_loops(const PerimeterGenerator &perime
 
     // Append thin walls to the nearest-neighbor search (only for first iteration)
     if (! thin_walls.empty()) {
+        // Orca: apply fuzzy skin to thin walls as well
+        for (auto& thin_wall : thin_walls) {
+            // First, we convert the ThickPolyline into Arachne::ExtrusionLine so we could reuse our existing fuzzy code
+            Arachne::ExtrusionLine el(0, true);
+            el.junctions.reserve(thin_wall.points.size());
+            for (int i = 0; i < thin_wall.points.size(); i++) {
+                el.junctions.emplace_back(thin_wall.points[i], thin_wall.width[i], 0);
+            }
+
+            // Then we fuzzy it
+            apply_fuzzy_skin(&el, perimeter_generator, true, thin_wall.is_closed());
+
+            // Then convert the result back to ThickPolyline
+            thin_wall = Arachne::to_thick_polyline(el);
+        }
+
         variable_width(thin_walls, erExternalPerimeter, perimeter_generator.ext_perimeter_flow, coll.entities);
         thin_walls.clear();
     }
@@ -1977,7 +1993,7 @@ void PerimeterGenerator::process_no_bridge(Surfaces& all_surfaces, coord_t perim
             ExPolygons unsupported = diff_ex(last, *this->lower_slices, ApplySafetyOffset::Yes);
             if (!unsupported.empty()) {
                 //remove small overhangs
-                ExPolygons unsupported_filtered = offset2_ex(unsupported, double(-perimeter_spacing), double(perimeter_spacing));
+                ExPolygons unsupported_filtered = opening_ex(unsupported, perimeter_spacing);
 
                 if (!unsupported_filtered.empty()) {
                     //to_draw.insert(to_draw.end(), last.begin(), last.end());
@@ -2090,35 +2106,40 @@ void PerimeterGenerator::process_no_bridge(Surfaces& all_surfaces, coord_t perim
                                 //TODO: add other polys as holes inside this one (-margin)
                             } else { // if(this->config->counterbore_hole_bridging.value == chbBridges)
                                 // Orca: Partial counterbore bridging is mask-based. Preserve the supported
-                                // remainder (`last`) and use simplified BridgeDetector coverage to derive the
+                                // remainder and use simplified BridgeDetector coverage to derive the
                                 // bridgeable counterbore span. The span is grown from supported material,
-                                // shrunk back, stripped from `last`, and expanded back. It is then prevented
-                                // from intruding deeper into `last` than the explicit anchor overlap.
-                                // Finally, add the allowed anchor band from `last` then remove the
+                                // shrunk back, stripped from the remaining normal surface, and expanded back.
+                                // It is then prevented from intruding deeper into it than the explicit anchor overlap.
+                                // Finally, add the allowed anchor band from it then remove the
                                 // narrow hole-side wall contact, which must remain unbridgeable.
 
-                                last = diff_ex(last, unsupported_filtered, ApplySafetyOffset::Yes);
+                                const ExPolygons remaining = diff_ex(last, unsupported_filtered, ApplySafetyOffset::Yes);
 
                                 ExPolygons bridgeable_filtered;
+
                                 for (ExPolygon& poly : bridgeable) {
                                     poly.simplify(perimeter_spacing, &bridgeable_filtered);
                                 }
                                 bridgeable_filtered = opening_ex(bridgeable_filtered, ext_perimeter_width);
 
                                 // Get rid of coarseness of the resulted bridgeable area by using the original supported area as reference.
-                                // This is to avoid keeping tiny bridgeable areas that are far from the supported area, or protrude into it. 
-                                bridgeable_filtered = union_ex(offset_ex(last, perimeter_spacing), bridgeable_filtered);
+                                // This is to avoid keeping tiny bridgeable areas that are far from the supported area, or protrude into it.
+                                bridgeable_filtered = union_ex(offset_ex(remaining, perimeter_spacing), bridgeable_filtered);
                                 bridgeable_filtered = offset_ex(bridgeable_filtered, -perimeter_spacing);
-                                bridgeable_filtered = diff_ex(bridgeable_filtered, last, ApplySafetyOffset::Yes);
+                                bridgeable_filtered = diff_ex(bridgeable_filtered, remaining, ApplySafetyOffset::Yes);
                                 bridgeable_filtered = opening_ex(bridgeable_filtered, perimeter_spacing); // filter noise from the diff_ex
                                 bridgeable_filtered = offset_ex(bridgeable_filtered, perimeter_spacing);  // restore the size to the original bridgeable area
                                 // Safety measure: Keep the bridge mask from intruding deeper into the
-                                // supported anchor region (`last`) than the explicit anchor overlap.
-                                bridgeable_filtered = diff_ex(bridgeable_filtered, offset_ex(last, -bridge_anchor_offset));
+                                // supported anchor region than the explicit anchor overlap.
+                                bridgeable_filtered = diff_ex(bridgeable_filtered, offset_ex(remaining, -bridge_anchor_offset));
 
-                                ExPolygons bridge_anchor_areas = intersection_ex(last, offset_ex(unsupported_filtered, bridge_anchor_offset));
+                                ExPolygons bridge_anchor_areas = intersection_ex(remaining, offset_ex(unsupported_filtered, bridge_anchor_offset));
                                 unsupported_filtered = union_ex(bridgeable_filtered, bridge_anchor_areas); // add bridge anchor
                                 unsupported_filtered = opening_ex(unsupported_filtered, bridge_anchor_offset); // remove anchor area from hole-side walls, it must remain unbridgeable
+
+                                // update 'last' only if we have a valid bridgeable area, otherwise we will lose the original unsupported area
+                                if (!unsupported_filtered.empty())
+                                    last = remaining;
                                 // TODO: Fix the case with thin outer walls around the bridge (1~2 walls) where classic wall
                                 // might generate two walls in a tiny space or non at all if "Detect thin walls" is not activated
                             }

src/libslic3r/PlaceholderParser.cpp

@@ -1791,6 +1791,8 @@ namespace client
             // from UTF8 to UTF16 don't bail out.
             msg += boost::nowide::narrow(boost::nowide::widen(error_line));
             msg += '\n';
+            // The error dialog (MsgDialog.cpp) renders this excerpt monospaced. It recognizes a source
+            // line directly above a caret line of spaces and a single '^'.
             for (size_t i = 0; i < error_pos; ++ i)
                 msg += ' ';
             msg += "^\n";

src/libslic3r/Preset.cpp

@@ -8,7 +8,9 @@
 
 #ifdef _MSC_VER
     #define WIN32_LEAN_AND_MEAN
+    #ifndef NOMINMAX
     #define NOMINMAX
+    #endif
     #include <Windows.h>
 #endif /* _MSC_VER */
 
@@ -147,6 +149,9 @@ Semver get_version_from_json(std::string file_path)
         return Semver();
         //throw ConfigurationError(format("Failed loading configuration file \"%1%\": %2%", file_path, err.what()));
     }
+    catch(...) {
+        return Semver();
+    }
 }
 
 //BBS: add a function to load the key-values from xxx.json
@@ -261,18 +266,28 @@ void extend_default_config_length(DynamicPrintConfig& config, const bool set_nil
         }
     };
 
+    // The four variant sets are immutable after static init and probed for every
+    // key of every preset loaded; one merged map makes that a single lookup.
+    // emplace keeps the first insertion, preserving the first-set-wins priority
+    // of the else-if chain this replaces.
+    static const std::unordered_map<std::string, int> variant_class = [] {
+        std::unordered_map<std::string, int> m;
+        for (const std::string& k : print_options_with_variant)     m.emplace(k, 0);
+        for (const std::string& k : filament_options_with_variant)  m.emplace(k, 1);
+        for (const std::string& k : printer_options_with_variant_1) m.emplace(k, 2);
+        for (const std::string& k : printer_options_with_variant_2) m.emplace(k, 3);
+        return m;
+    }();
+
     for(auto& key :config.keys()){
-        if(auto iter = print_options_with_variant.find(key); iter != print_options_with_variant.end()){
-            replace_nil_and_resize(key, process_variant_length);
-        }
-        else if(auto iter = filament_options_with_variant.find(key); iter != filament_options_with_variant.end()){
-            replace_nil_and_resize(key, filament_variant_length);
-        }
-        else if(auto iter = printer_options_with_variant_1.find(key); iter != printer_options_with_variant_1.end()){
-            replace_nil_and_resize(key, machine_variant_length);
-        }
-        else if(auto iter = printer_options_with_variant_2.find(key); iter != printer_options_with_variant_2.end()){
-            replace_nil_and_resize(key, machine_variant_length * 2);
+        auto iter = variant_class.find(key);
+        if (iter == variant_class.end())
+            continue;
+        switch (iter->second) {
+        case 0: replace_nil_and_resize(key, process_variant_length); break;
+        case 1: replace_nil_and_resize(key, filament_variant_length); break;
+        case 2: replace_nil_and_resize(key, machine_variant_length); break;
+        case 3: replace_nil_and_resize(key, machine_variant_length * 2); break;
         }
     }
 }
@@ -1037,6 +1052,7 @@ static std::vector<std::string> s_Preset_print_options{
     "fill_multiline",
     "gyroid_optimized",
     "sparse_infill_pattern",
+    "sparse_infill_smooth_factor",
     "lateral_lattice_angle_1",
     "lateral_lattice_angle_2",
     "infill_overhang_angle",
@@ -1090,7 +1106,7 @@ static std::vector<std::string> s_Preset_print_options{
     "top_surface_speed", "support_speed", "support_object_xy_distance", "support_object_first_layer_gap", "support_interface_speed",
     "bridge_speed", "internal_bridge_speed", "gap_infill_speed", "travel_speed", "travel_speed_z", "initial_layer_speed",
     "outer_wall_acceleration", "initial_layer_acceleration", "top_surface_acceleration", "default_acceleration", "skirt_type", "skirt_loops", "skirt_speed","min_skirt_length", "skirt_distance", "skirt_start_angle", "skirt_height","single_loop_draft_shield", "draft_shield",
-    "brim_width", "leading_brim_length", "extra_brim_width", "brim_object_gap", "brim_flow_ratio", "brim_use_efc_outline", "combine_brims", "brim_type", "brim_ears_max_angle", "brim_ears_detection_length", "enable_support", "support_type", "support_threshold_angle", "support_threshold_overlap","enforce_support_layers",
+    "brim_width", "leading_brim_length", "extra_brim_width", "brim_object_gap", "brim_flow_ratio", "brim_use_efc_outline", "combine_brims", "brim_type", "brim_ears_max_angle", "brim_ears_detection_length", "brim_ears_outer_only", "enable_support", "support_type", "support_threshold_angle", "support_threshold_overlap","enforce_support_layers",
     "raft_layers", "raft_first_layer_density", "raft_first_layer_expansion", "raft_contact_distance", "raft_expansion",
     "support_base_pattern", "support_base_pattern_spacing", "support_expansion", "support_style",
     // BBS
@@ -1352,6 +1368,8 @@ static std::vector<std::string> s_Preset_filament_options {/*"filament_colour",
     "filament_retraction_length",
     "filament_retraction_minimum_travel",
     "filament_retraction_speed",
+    "filament_retract_length_toolchange",
+    "filament_retract_restart_extra_toolchange",
     "filament_wipe",
     "filament_z_hop",
     "filament_z_hop_types",
@@ -1413,7 +1431,7 @@ static std::vector<std::string> s_Preset_printer_options {
     "first_layer_plane", "first_layer_plane_offset", "first_layer_plane_thickness",
     "belt_support_floor_offset", "belt_support_floor_mode", "belt_support_z_offset_mode",
     "enable_belt_purge_tower",
-    "gcode_flavor",
+    "gcode_flavor", "gcode_skip_config_block",
     "fan_kickstart", "part_cooling_fan_min_pwm", "fan_speedup_time", "fan_speedup_overhangs",
     "single_extruder_multi_material", "manual_filament_change", "file_start_gcode", "machine_start_gcode", "machine_end_gcode", "before_layer_change_gcode", "printing_by_object_gcode", "layer_change_gcode", "time_lapse_gcode", "wrapping_detection_gcode", "change_filament_gcode", "change_extrusion_role_gcode",
     "printer_model", "printer_variant", "printer_extruder_id", "printer_extruder_variant", "extruder_variant_list", "default_nozzle_volume_type",
@@ -1431,7 +1449,7 @@ static std::vector<std::string> s_Preset_printer_options {
     "use_relative_e_distances", "extruder_type", "use_firmware_retraction", "printer_notes",
     "grab_length", "support_object_skip_flush", "physical_extruder_map",
     "cooling_tube_retraction",
-    "cooling_tube_length", "high_current_on_filament_swap", "parking_pos_retraction", "extra_loading_move", "wipe_tower_type", "purge_in_prime_tower", "enable_filament_ramming", "tool_change_on_wipe_tower",
+    "cooling_tube_length", "high_current_on_filament_swap", "parking_pos_retraction", "extra_loading_move", "wipe_tower_type", "purge_in_prime_tower", "enable_filament_ramming", "tool_change_on_wipe_tower", "wait_for_temp_on_wipe_tower",
     "z_offset",
     "disable_m73", "preferred_orientation", "emit_machine_limits_to_gcode", "pellet_modded_printer", "support_multi_bed_types", "use_3mf", "default_bed_type", "bed_mesh_min","bed_mesh_max","bed_mesh_probe_distance", "adaptive_bed_mesh_margin", "enable_long_retraction_when_cut","long_retractions_when_cut","retraction_distances_when_cut",
     "bed_temperature_formula", "nozzle_flush_dataset",
@@ -3794,12 +3812,14 @@ void PresetCollection::update_library_profile_excluded_from()
     }
 
     // Check all presets that has the same alias as the filament presets with empty compatible_printers in Orca Filament Library.
+    // A printer specific profile supersedes the generic one, no matter whether it lives in a vendor bundle or in the
+    // library itself.
     for (const Preset& preset : m_presets) {
-        if (preset.vendor == nullptr || preset.vendor->name == PresetBundle::ORCA_FILAMENT_LIBRARY)
+        if (preset.vendor == nullptr)
             continue;
 
         const auto* compatible_printers = dynamic_cast<const ConfigOptionStrings*>(preset.config.option("compatible_printers"));
-        // All profiles in concrete vendor profile shouldn't have empty compatible_printers, but here we check it for safety.
+        // Profiles with empty compatible_printers are the generic ones, they never supersede anything.
         if (compatible_printers == nullptr || compatible_printers->values.empty())
             continue;
         auto itr = excluded_froms.find(preset.alias);

src/libslic3r/Preset.hpp

@@ -131,6 +131,10 @@ public:
         PrinterVariant() {}
         PrinterVariant(const std::string &name) : name(name) {}
         std::string                 name;
+
+        // All fields, declaration order — keep in sync; bump CACHE_VERSION on change.
+        template<class Archive>
+        void serialize(Archive& ar) { ar(name); }                       // PrinterVariant
     };
 
     struct PrinterModel {
@@ -139,7 +143,7 @@ public:
         std::string                 name;
         //BBS: this is internal id for the printer. Currently only used for searching in database
         std::string                 model_id;
-        PrinterTechnology           technology;
+        PrinterTechnology           technology = ptFFF;
         std::string                 family;
         std::vector<PrinterVariant> variants;
         std::vector<std::string>	default_materials;
@@ -162,6 +166,17 @@ public:
         }
 
         const PrinterVariant* variant(const std::string &name) const { return const_cast<PrinterModel*>(this)->variant(name); }
+
+        // All fields, declaration order — keep in sync; bump CACHE_VERSION on change.
+        template<class Archive>
+        void serialize(Archive& ar)                                     // PrinterModel
+        {
+            ar(id, name, model_id, technology, family, variants, default_materials,
+               not_support_bed_types, bed_model, bed_texture, image_bed_type,
+               bottom_texture_end_name, use_double_extruder_default_texture,
+               bottom_texture_rect, bottom_texture_rect_longer, middle_texture_rect,
+               hotend_model);
+        }
     };
     std::vector<PrinterModel>          models;
 
@@ -173,6 +188,14 @@ public:
 
     bool 		valid() const { return ! name.empty() && ! id.empty() && config_version.valid(); }
 
+    // All fields, declaration order — keep in sync; bump CACHE_VERSION on change.
+    template<class Archive>
+    void serialize(Archive& ar)                                         // VendorProfile
+    {
+        ar(name, id, config_version, config_update_url, changelog_url,
+           models, default_filaments, default_sla_materials);
+    }
+
     // Load VendorProfile from an ini file.
     // If `load_all` is false, only the header with basic info (name, version, URLs) is loaded.
     static VendorProfile from_ini(const boost::filesystem::path &path, bool load_all=true);
@@ -427,10 +450,10 @@ public:
     Preset(Type type, const std::string &name, bool is_default = false) : type(type), is_default(is_default), name(name) {}
 
 protected:
-    Preset() = default;
-
     friend class        PresetCollection;
     friend class        PresetBundle;
+
+    Preset() = default;
 };
 
 bool is_compatible_with_print  (const PresetWithVendorProfile &preset, const PresetWithVendorProfile &active_print, const PresetWithVendorProfile &active_printer);

src/libslic3r/PresetBundle.hpp

@@ -2,10 +2,12 @@
 #define slic3r_PresetBundle_hpp_
 
 #include "Preset.hpp"
+#include "PresetCacheFormat.hpp"
 #include "AppConfig.hpp"
 #include "enum_bitmask.hpp"
 
 #include <memory>
+#include <set>
 #include <shared_mutex>
 #include <unordered_map>
 #include <optional>
@@ -170,6 +172,31 @@ struct PresetBundleMetadata
 class PresetBundle
 {
 public:
+    // ---- Per-vendor preset cache --------------------------------------------
+    // One cache file per vendor (plus the Orca filament library), stamped with
+    // the vendor's own profile version rather than a directory scan. The bytes
+    // on disk are VendorCacheFile's business (PresetCacheFormat.hpp); what
+    // lives here is how a cache's contents install into a bundle.
+
+    // The cache is not something a caller loads from: a vendor is loaded with
+    // load_vendor_configs_from_json, which comes from the cache whenever one covers
+    // it. What is public here is what the cache's own tests drive directly.
+
+    // Load a per-vendor cache into this bundle by installing its entries, with
+    // base_bundle's filament library as the inheritance base. Rejects (returns
+    // false, with this bundle left clean) unless VendorCacheFile::load accepts
+    // the file — see its contract for the version and identity checks — and
+    // every entry installs. Options this build no longer defines are dropped,
+    // not fatal — the payload names its own keys.
+    bool load_vendor_cache(const std::string& cache_path, const std::string& expected_vendor_name,
+                          const Semver& expected_vendor_version, const PresetBundle* base_bundle = nullptr);
+
+    // Enable writing a per-vendor cache after a JSON parse (off by default). Cache
+    // content is pure parse output, so the guard is policy, not correctness: only
+    // the deliberate generators (load_system_presets_from_json, the cache build
+    // tool) write files, not every incidental load a dialog performs.
+    void set_generate_vendor_caches(bool enable) { m_generate_vendor_caches = enable; }
+
     static DynamicPrintConfig construct_full_config(Preset                         &in_printer_preset,
                                                     Preset                         &in_print_preset,
                                                     const DynamicPrintConfig       &project_config,
@@ -444,8 +471,12 @@ public:
     /*std::pair<PresetsConfigSubstitutions, size_t> load_configbundle(
         const std::string &path, LoadConfigBundleAttributes flags, ForwardCompatibilitySubstitutionRule compatibility_rule);*/
     //Orca: load config bundle from json, pass the base bundle to support cross vendor inheritance
+    // Orca: `dir` is where the vendor is looked for — its own directory, whether or
+    // not the profile JSONs are still there. A whole-vendor load comes from the
+    // vendor's preset cache whenever one covers the profile on disk, and is parsed
+    // from the JSONs in `dir` only when none does. Nothing here reads resources.
     std::pair<PresetsConfigSubstitutions, size_t> load_vendor_configs_from_json(
-        const std::string &path, const std::string &vendor_name, LoadConfigBundleAttributes flags, ForwardCompatibilitySubstitutionRule compatibility_rule, const PresetBundle* base_bundle = nullptr);
+        const std::string &dir, const std::string &vendor_name, LoadConfigBundleAttributes flags, ForwardCompatibilitySubstitutionRule compatibility_rule, const PresetBundle* base_bundle = nullptr);
 
     // Export a config bundle file containing all the presets and the names of the active presets.
     //void                        export_configbundle(const std::string &path, bool export_system_settings = false, bool export_physical_printers = false);
@@ -517,11 +548,49 @@ public:
     // Orca: for validation only.
     bool has_errors(bool check_duplicate_filament_subtypes = false) const;
 
+    // Errors the last load recorded. What the cache's error accounting promises —
+    // a cache-served vendor reports what its parse would — is pinned against this.
+    int error_count() const { return m_errors; }
+
     // Orca: for validation only. Flag any system preset whose inherits / compatible_printers /
     // compatible_prints references a deleted (unknown) or renamed (old) preset name.
     bool check_preset_references() const;
 
+    // Merge one vendor's presets with the other vendor's presets, report duplicates.
+    // Public so per-vendor-cache consumers (e.g. the setup wizard) can assemble a
+    // bundle out of several per-vendor caches loaded into separate PresetBundle instances.
+    std::vector<std::string>    merge_presets(PresetBundle &&other);
+
 private:
+    // Load one vendor from the preset cache installed in `dir`, judged against
+    // the vendor profile there. False, with this bundle left clean, when there
+    // is no usable cache and the vendor has to be parsed. This is how
+    // load_vendor_configs_from_json reads a cache.
+    bool load_vendor_cache(const boost::filesystem::path& dir, const std::string& vendor_name, const PresetBundle* base_bundle);
+
+    // Load one source-form preset entry into this bundle: resolve `inherits`,
+    // flatten, validate and register the preset. Returns the reason loading
+    // failed, empty on success. See the definition for the sharing contract
+    // between the JSON parse and the cache load.
+    // retain_configs, when non-null, names the only presets registered into
+    // config_maps (a full config copy each). The cache load passes the names its
+    // entries inherit — the only ones ever looked up again; the JSON parse
+    // retains all, not knowing what later subfiles inherit.
+    std::string load_vendor_preset(const CachedPreset& entry,
+        const std::string& path, const std::string& vendor_name,
+        const PresetBundle* base_bundle,
+        LoadConfigBundleAttributes flags,
+        ConfigSubstitutionContext& substitution_context, PresetsConfigSubstitutions& substitutions,
+        std::map<std::string, DynamicPrintConfig>& config_maps, std::map<std::string, std::string>& filament_id_maps,
+        PresetCollection* presets_collection, size_t& count, bool is_from_lib,
+        const std::set<std::string>* retain_configs = nullptr);
+
+    // Clear every collection's m_printer_hold_alias, which reset() leaves alone.
+    void clear_printer_hold_aliases();
+
+    // Whether to (re)write a per-vendor cache after a JSON parse.
+    bool m_generate_vendor_caches { false };
+
     // Orca: validation only - flag any printer with two or more compatible
     // filament presets sharing one filament_id (ambiguous AMS subtype match).
     bool check_duplicate_filament_subtypes() const;
@@ -529,8 +598,6 @@ private:
     //std::pair<PresetsConfigSubstitutions, std::string> load_system_presets(ForwardCompatibilitySubstitutionRule compatibility_rule);
     //BBS: add json related logic
     std::pair<PresetsConfigSubstitutions, std::string> load_system_presets_from_json(ForwardCompatibilitySubstitutionRule compatibility_rule);
-    // Merge one vendor's presets with the other vendor's presets, report duplicates.
-    std::vector<std::string>    merge_presets(PresetBundle &&other);
     // Update the multicolor information for filaments.
     void update_filament_multi_color();
     // Update renamed_from and alias maps of system profiles.

src/libslic3r/PresetCacheFormat.cpp

@@ -0,0 +1,588 @@
+#include "libslic3r/PresetCacheFormat.hpp"
+
+#include <algorithm>
+#include <memory>
+#include <sstream>
+#include <stdexcept>
+#include <utility>
+
+#include <boost/crc.hpp>
+#include <boost/filesystem.hpp>
+#include <boost/iostreams/device/array.hpp>
+#include <boost/iostreams/stream.hpp>
+#include <boost/log/trivial.hpp>
+#include <boost/nowide/fstream.hpp>
+#include <cereal/types/map.hpp>
+#include <cereal/types/set.hpp>
+
+#include "libslic3r/Utils.hpp"
+
+namespace Slic3r {
+
+CacheDictionary::CacheDictionary()
+{
+    // ENUM_UNNAMED is index 0 and always the empty name.
+    m_enum_values.emplace_back();
+}
+
+// The ints an enum option holds — one for a coEnum, the whole vector for coEnums.
+static std::vector<int> enum_ints(const ConfigOptionDef& def, const ConfigOption* opt)
+{
+    if (def.type == coEnum)
+        return { opt->getInt() };
+    return static_cast<const ConfigOptionInts*>(opt)->values;
+}
+
+// The name this build gives one of those ints, empty where it has none — a
+// nullable option's nil, or a definition carrying no enum_keys_map. Enums are
+// written by name so a build that reorders an enum's values still reads it right.
+static std::string enum_name_of(const ConfigOptionDef& def, int value)
+{
+    if (def.enum_keys_map != nullptr)
+        for (const auto& kvp : *def.enum_keys_map)
+            if (kvp.second == value)
+                return kvp.first;
+    return {};
+}
+
+void CacheDictionary::collect(const DynamicPrintConfig& config)
+{
+    for (auto it = config.cbegin(); it != config.cend(); ++ it) {
+        const ConfigOptionDef* def = print_config_def.get(it->first);
+        if (def == nullptr)
+            continue;   // save_config does not write it either
+        if (m_key_index.try_emplace(it->first, uint16_t(m_keys.size())).second) {
+            m_keys.push_back(it->first);
+            m_types.push_back(uint16_t(def->type));
+        }
+        if (def->type != coEnum && def->type != coEnums)
+            continue;
+        for (int value : enum_ints(*def, it->second.get())) {
+            std::string name = enum_name_of(*def, value);
+            if (! name.empty() && m_enum_index.try_emplace(name, uint16_t(m_enum_values.size())).second)
+                m_enum_values.push_back(std::move(name));
+        }
+    }
+}
+
+uint16_t CacheDictionary::key_index(const t_config_option_key& key) const
+{
+    auto it = m_key_index.find(key);
+    if (it == m_key_index.end())
+        throw std::runtime_error("preset cache: option " + key + " was never collected into the dictionary");
+    return it->second;
+}
+
+uint16_t CacheDictionary::enum_index(const std::string& name) const
+{
+    if (name.empty())
+        return ENUM_UNNAMED;
+    auto it = m_enum_index.find(name);
+    return it == m_enum_index.end() ? ENUM_UNNAMED : it->second;
+}
+
+void CacheDictionary::save(cereal::BinaryOutputArchive& ar) const
+{
+    // Checked here rather than left to the caller: an index that wrapped would
+    // be written silently, and nothing downstream could tell.
+    if (m_keys.size() > MAX_ENTRIES || m_enum_values.size() > MAX_ENTRIES)
+        throw std::runtime_error("preset cache: the option dictionary outgrew the uint16 it is indexed with");
+    ar(m_keys, m_types, m_enum_values);
+}
+
+void CacheDictionary::load(cereal::BinaryInputArchive& ar)
+{
+    ar(m_keys, m_types, m_enum_values);
+    if (m_keys.size() != m_types.size())
+        throw std::runtime_error("preset cache: dictionary key and type tables differ in length");
+    if (m_keys.size() > MAX_ENTRIES || m_enum_values.size() > MAX_ENTRIES)
+        throw std::runtime_error("preset cache: dictionary is larger than the uint16 it is indexed with");
+    if (m_enum_values.empty() || ! m_enum_values.front().empty())
+        throw std::runtime_error("preset cache: dictionary is missing its unnamed-enum slot");
+    // Resolved once per file: every option read after this is a vector index.
+    m_defs.resize(m_keys.size());
+    for (size_t i = 0; i < m_keys.size(); ++ i) {
+        const ConfigOptionDef* def = print_config_def.get(m_keys[i]);
+        m_defs[i] = (def != nullptr && uint16_t(def->type) == m_types[i]) ? def : nullptr;
+    }
+}
+
+// ---- one config -----------------------------------------------------------
+
+static void save_enum_option(cereal::BinaryOutputArchive& ar, const ConfigOptionDef& def,
+                             const ConfigOption* opt, const CacheDictionary& dict)
+{
+    const std::vector<int> values = enum_ints(def, opt);
+    ar(uint32_t(values.size()));
+    for (int value : values) {
+        const uint16_t idx = dict.enum_index(enum_name_of(def, value));
+        ar(idx);
+        if (idx == CacheDictionary::ENUM_UNNAMED)
+            ar(int32_t(value));
+    }
+}
+
+// `config` may be null, in which case the option is read and dropped.
+static void load_enum_option(cereal::BinaryInputArchive& ar, ConfigOptionType type,
+                             const ConfigOptionDef* def, DynamicPrintConfig* config,
+                             const CacheDictionary& dict)
+{
+    uint32_t cnt = 0;
+    ar(cnt);
+    if (type == coEnum && cnt != 1)
+        throw std::runtime_error("preset cache: a scalar enum carrying more than one value");
+    // Every element is read whatever happens, so the stream stays in sync and
+    // whatever follows this option still loads.
+    bool usable = def != nullptr && config != nullptr;
+    std::vector<int> values;
+    values.reserve(cnt);
+    for (uint32_t i = 0; i < cnt; ++ i) {
+        uint16_t idx = 0;
+        ar(idx);
+        if (! dict.valid_enum_index(idx))
+            throw std::runtime_error("preset cache: enum value index past the end of the dictionary");
+        if (idx == CacheDictionary::ENUM_UNNAMED) {
+            // An int the writer could not name — a nil, or an option whose
+            // definition carried no enum_keys_map. It travels verbatim.
+            int32_t raw = 0;
+            ar(raw);
+            values.push_back(int(raw));
+            continue;
+        }
+        if (! usable)
+            continue;             // the index above was this element's whole payload
+        if (def->enum_keys_map == nullptr) {
+            usable = false;       // this build no longer maps this option's names
+            continue;
+        }
+        const auto it = def->enum_keys_map->find(dict.enum_name_at(idx));
+        if (it == def->enum_keys_map->end()) {
+            usable = false;       // a value this build dropped: the option goes with it
+            continue;
+        }
+        values.push_back(it->second);
+    }
+    if (! usable)
+        return;
+    if (type == coEnum) {
+        config->set_key_value(def->opt_key, new ConfigOptionEnumGeneric(def->enum_keys_map, values.front()));
+    } else {
+        auto* opt = def->nullable ? static_cast<ConfigOptionInts*>(new ConfigOptionEnumsGenericNullable(def->enum_keys_map))
+                                  : static_cast<ConfigOptionInts*>(new ConfigOptionEnumsGeneric(def->enum_keys_map));
+        opt->values = std::move(values);
+        config->set_key_value(def->opt_key, opt);
+    }
+}
+
+void save_config(cereal::BinaryOutputArchive& ar, const DynamicPrintConfig& config, const CacheDictionary& dict)
+{
+    struct Written { uint16_t idx; const ConfigOptionDef* def; const ConfigOption* opt; };
+    std::vector<Written> written;
+    written.reserve(config.size());
+    for (auto it = config.cbegin(); it != config.cend(); ++ it)
+        if (const ConfigOptionDef* def = print_config_def.get(it->first))
+            written.push_back({ dict.key_index(it->first), def, it->second.get() });
+
+    ar(uint32_t(written.size()));
+    for (const Written& w : written) {
+        ar(w.idx);
+        if (w.def->type == coEnum || w.def->type == coEnums)
+            save_enum_option(ar, *w.def, w.opt, dict);
+        else
+            w.def->save_option_to_archive(ar, w.opt);
+    }
+}
+
+// `config` null means: read everything, keep nothing.
+static void read_config(cereal::BinaryInputArchive& ar, DynamicPrintConfig* config, const CacheDictionary& dict)
+{
+    uint32_t cnt = 0;
+    ar(cnt);
+    if (config != nullptr)
+        config->clear();
+    // Reused across the loop: constructing a ConfigOptionDef per dropped option
+    // would allocate its strings and vectors for nothing.
+    ConfigOptionDef scratch;
+    for (uint32_t i = 0; i < cnt; ++ i) {
+        uint16_t idx = 0;
+        ar(idx);
+        if (! dict.valid_key_index(idx))
+            throw std::runtime_error("preset cache: option index past the end of the dictionary");
+        const ConfigOptionType type = dict.type_at(idx);
+        const ConfigOptionDef* def  = dict.def_at(idx);
+        if (type == coEnum || type == coEnums) {
+            load_enum_option(ar, type, def, config, dict);
+        } else if (def != nullptr && config != nullptr) {
+            config->set_key_value(def->opt_key, def->load_option_from_archive(ar));
+        } else {
+            // Read by the type the writer recorded, then drop: the same outcome
+            // a JSON profile gets for an option this build no longer has.
+            scratch.type = type;
+            std::unique_ptr<ConfigOption> discard(scratch.load_option_from_archive(ar));
+        }
+    }
+}
+
+void load_config(cereal::BinaryInputArchive& ar, DynamicPrintConfig& config, const CacheDictionary& dict)
+{
+    read_config(ar, &config, dict);
+}
+
+void skip_config(cereal::BinaryInputArchive& ar, const CacheDictionary& dict)
+{
+    read_config(ar, nullptr, dict);
+}
+
+// ---- The per-vendor cache file (<vendor>.opc) -----------------------------
+
+namespace {
+
+#pragma pack(push, 1)
+struct CacheFileHeader {
+    uint32_t magic;
+    uint32_t version;
+    uint64_t data_size;
+    uint32_t crc32;
+};
+#pragma pack(pop)
+static_assert(sizeof(CacheFileHeader) == 20, "CacheFileHeader must be 20 bytes");
+
+constexpr uint32_t CACHE_MAGIC   = 0x4F52435A; // "ORCZ"
+// Bump when the wire format changes in a way the payload cannot describe
+// itself out of: reordering, removing or retyping a field of a hand-written
+// serialize() (VendorProfile and its nested types, CachedPreset via
+// save_entries below), or a change to the cache's own layout or the
+// meaning of its stamps. Option-schema drift is NOT such a change — the
+// dictionary handles it, which is why this no longer moves every release.
+constexpr uint32_t CACHE_VERSION = 1;
+
+// A stamp-string read that refuses an absurd length before allocating anything.
+// The stamps are read from files named from the outside (peek_version is
+// pointed at whatever <vendor>.opc a directory holds), so the length word may
+// be arbitrary bytes — and a resize to a garbage 64-bit length does not fail as
+// a catchable bad_alloc here, it takes the app down through the out-of-memory
+// handler. A vendor name or profile version is a short token; anything longer
+// is not a cache this build wrote.
+std::string read_bounded_string(cereal::BinaryInputArchive& ar)
+{
+    constexpr uint64_t MAX_STAMP_LEN = 1024;
+    cereal::size_type len = 0;
+    ar(cereal::make_size_tag(len));
+    if (uint64_t(len) > MAX_STAMP_LEN)
+        throw std::runtime_error("preset cache: string length out of bounds");
+    std::string s(size_t(len), '\0');
+    ar(cereal::binary_data(s.data(), size_t(len)));
+    return s;
+}
+
+// The prologue every cache reader starts with: the format version, then the
+// vendor's identity. Returns the vendor version stamped on a body this build can
+// read, empty on anything else — which is the same answer as "not this vendor".
+std::string read_cache_stamps(cereal::BinaryInputArchive& ar, const std::string& expected_vendor_name)
+{
+    // The version is judged before anything variable-length is read: on a body
+    // that is not a per-vendor cache of this version, the bytes where a string
+    // length would sit may be arbitrary framing.
+    uint32_t cache_version = 0;
+    ar(cache_version);
+    if (cache_version != CACHE_VERSION)
+        return {};
+    const std::string vendor_name    = read_bounded_string(ar);
+    const std::string vendor_version = read_bounded_string(ar);
+    if (vendor_name != expected_vendor_name)
+        return {};
+    return vendor_version;
+}
+
+// A cache stays usable as long as it was built from a vendor profile at least
+// as new as the one now on disk. Profiles whose version is invalid cannot be
+// judged this way and are never served from cache; where no profile sits
+// beside the cache at all, nothing can be newer than it — that state is passed
+// as Semver::inf(), which no real profile can carry (an invalid version could
+// not say it apart from "profile there but unjudgeable", and zero would
+// collide with a genuine "0.0.0"). This is the serve rule; the install rule
+// (cache_covers in PresetBundle.cpp) deliberately reads an unjudgeable profile
+// the other way, so the two are not one function.
+bool cache_covers_version(const std::string& cached, const Semver& on_disk)
+{
+    if (on_disk == Semver::inf())
+        return true;    // before parsing `cached`: nothing exists that the stamp must cover
+    if (! on_disk.valid())
+        return false;
+    const auto cached_ver = Semver::parse(cached);
+    return cached_ver && *cached_ver >= on_disk;
+}
+
+// CachedPreset on the wire: all fields, declaration order, in one place.
+// `config` writes, reads or skips the config sitting in the middle of that
+// order — the three things a reader can want to do with it — so save, load and
+// the name peek below cannot drift apart. Keep in sync with the struct in
+// PresetCacheFormat.hpp and bump CACHE_VERSION on change. Written here rather
+// than as a serialize() member because the config needs the file's dictionary,
+// which cereal cannot thread through one.
+template<class Archive, class Entry, class ConfigFn>
+void visit_entry(Archive& ar, Entry& e, ConfigFn&& config)
+{
+    ar(e.name, e.sub_path);
+    config();
+    ar(e.inherits, e.description, e.instantiation, e.setting_id, e.filament_id, e.renamed_from);
+}
+
+// The count comes from a file that has already passed magic and CRC, but a
+// reserve is a promise to allocate: cap it and let push_back grow the rest.
+constexpr uint32_t MAX_RESERVED_ENTRIES = 4096;
+
+void save_entries(cereal::BinaryOutputArchive& ar,
+                  const std::vector<CachedPreset>& entries,
+                  const CacheDictionary& dict)
+{
+    ar(uint32_t(entries.size()));
+    for (const CachedPreset& e : entries)
+        visit_entry(ar, e, [&] { save_config(ar, e.config_src, dict); });
+}
+
+void load_entries(cereal::BinaryInputArchive& ar,
+                  std::vector<CachedPreset>& entries,
+                  const CacheDictionary& dict)
+{
+    uint32_t cnt = 0;
+    ar(cnt);
+    entries.clear();
+    entries.reserve(std::min(cnt, MAX_RESERVED_ENTRIES));
+    for (uint32_t i = 0; i < cnt; ++ i) {
+        CachedPreset e;
+        visit_entry(ar, e, [&] { load_config(ar, e.config_src, dict); });
+        entries.push_back(std::move(e));
+    }
+}
+
+// Read a raw cache body: verify magic, size, CRC.
+bool read_cache_blob(const std::string& path, std::string& out_blob)
+{
+    try {
+        boost::nowide::ifstream ifs(path, std::ios::binary);
+        if (!ifs.is_open())
+            return false;
+        CacheFileHeader fhdr;
+        if (!ifs.read(reinterpret_cast<char*>(&fhdr), sizeof(fhdr)))
+            return false;
+        if (fhdr.magic != CACHE_MAGIC)
+            return false;
+        // data_size is 8 bytes from a file nothing has authenticated yet, and
+        // it is about to size an allocation. The body is the whole of the file
+        // behind the header — anything else is not a cache this build wrote.
+        ifs.seekg(0, std::ios::end);
+        const std::streamoff file_size = ifs.tellg();
+        if (file_size < std::streamoff(sizeof(fhdr)) ||
+            fhdr.data_size == 0 ||
+            fhdr.data_size != uint64_t(file_size) - sizeof(fhdr))
+            return false;
+        ifs.seekg(sizeof(fhdr), std::ios::beg);
+        out_blob.assign(fhdr.data_size, '\0');
+        if (!ifs.read(&out_blob[0], static_cast<std::streamsize>(fhdr.data_size)))
+            return false;
+        boost::crc_32_type crc;
+        crc.process_bytes(out_blob.data(), out_blob.size());
+        if (crc.checksum() != fhdr.crc32) {
+            BOOST_LOG_TRIVIAL(warning) << "VendorCacheFile: CRC mismatch: " << path;
+            return false;
+        }
+        return true;
+    } catch (const std::exception& e) {
+        BOOST_LOG_TRIVIAL(warning) << "VendorCacheFile: read failed (" << path << "): " << e.what();
+        return false;
+    }
+}
+
+// Write a cache body behind the standard 20-byte file header. False when the
+// file could not be opened or written whole.
+bool write_cache_blob(const std::string& path, const std::string& blob)
+{
+    boost::crc_32_type crc;
+    crc.process_bytes(blob.data(), blob.size());
+    // Written beside the target and moved into place, as AppConfig::save does:
+    // a cache is truncated and rewritten in full, so a write that dies partway
+    // would otherwise leave a header claiming more body than the file holds.
+    // The PID suffix also keeps two instances writing the same vendor from
+    // interleaving.
+    const std::string tmp_path = path + "." + std::to_string(get_current_pid()) + ".tmp";
+    try {
+        boost::filesystem::create_directories(boost::filesystem::path(path).parent_path());
+        {
+            boost::nowide::ofstream ofs(tmp_path, std::ios::binary | std::ios::trunc);
+            if (!ofs.is_open()) {
+                BOOST_LOG_TRIVIAL(warning) << "VendorCacheFile: cannot open for writing: " << tmp_path;
+                return false;
+            }
+            CacheFileHeader fhdr;
+            fhdr.magic     = CACHE_MAGIC;
+            fhdr.version   = CACHE_VERSION;
+            fhdr.data_size = static_cast<uint64_t>(blob.size());
+            fhdr.crc32     = crc.checksum();
+            ofs.write(reinterpret_cast<const char*>(&fhdr), sizeof(fhdr));
+            ofs.write(blob.data(), static_cast<std::streamsize>(blob.size()));
+            ofs.close();   // flush; close() raises failbit on error
+            if (! ofs.good()) {
+                BOOST_LOG_TRIVIAL(warning) << "VendorCacheFile: write failed (" << tmp_path << ")";
+                boost::system::error_code ec;
+                boost::filesystem::remove(tmp_path, ec);
+                return false;
+            }
+        }
+        if (const std::error_code ec = rename_file(tmp_path, path)) {
+            BOOST_LOG_TRIVIAL(warning) << "VendorCacheFile: could not move " << tmp_path << " into place: " << ec.message();
+            boost::system::error_code rm;
+            boost::filesystem::remove(tmp_path, rm);
+            return false;
+        }
+        return true;
+    } catch (const std::exception& e) {
+        BOOST_LOG_TRIVIAL(warning) << "VendorCacheFile: write failed (" << path << "): " << e.what();
+        boost::system::error_code ec;
+        boost::filesystem::remove(tmp_path, ec);
+        return false;
+    }
+}
+
+} // anonymous namespace
+
+// static
+bool VendorCacheFile::save(const std::string& path, const std::string& vendor_name,
+                           const std::string& vendor_version, const VendorCacheData& data)
+{
+    try {
+        // Collected before anything is written: the dictionary sits ahead of the
+        // entries so a reader resolves it once and then indexes.
+        CacheDictionary dict;
+        for (const std::vector<CachedPreset>* entries : { &data.process_entries, &data.filament_entries, &data.machine_entries })
+            for (const CachedPreset& e : *entries)
+                dict.collect(e.config_src);
+
+        std::ostringstream body(std::ios::binary);
+        {
+            cereal::BinaryOutputArchive ar(body);
+            ar(CACHE_VERSION);
+            ar(vendor_name, vendor_version);
+            dict.save(ar);
+            ar(data.vendors);
+            save_entries(ar, data.process_entries, dict);
+            save_entries(ar, data.filament_entries, dict);
+            save_entries(ar, data.machine_entries, dict);
+            ar(data.parse_errors);
+        }
+        return write_cache_blob(path, body.str());
+    } catch (const std::exception& e) {
+        BOOST_LOG_TRIVIAL(warning) << "VendorCacheFile: failed to save vendor cache " << path << ": " << e.what();
+        return false;
+    }
+}
+
+// static
+bool VendorCacheFile::load(const std::string& path, const std::string& expected_vendor_name,
+                           const Semver& expected_vendor_version, VendorCacheData& data)
+{
+    std::string blob;
+    if (! read_cache_blob(path, blob))
+        return false;
+    try {
+        // Read in place: an istringstream would copy the blob once more just to
+        // stream over it.
+        boost::iostreams::stream<boost::iostreams::array_source> body(blob.data(), blob.size());
+        cereal::BinaryInputArchive ar(body);
+        const std::string vendor_version = read_cache_stamps(ar, expected_vendor_name);
+        if (vendor_version.empty() || ! cache_covers_version(vendor_version, expected_vendor_version))
+            return false;
+        CacheDictionary dict;
+        dict.load(ar);
+        ar(data.vendors);
+        load_entries(ar, data.process_entries, dict);
+        load_entries(ar, data.filament_entries, dict);
+        load_entries(ar, data.machine_entries, dict);
+        ar(data.parse_errors);
+        if (data.vendors.find(expected_vendor_name) == data.vendors.end())
+            throw std::runtime_error("vendor cache does not carry its own vendor profile");
+        return true;
+    } catch (const std::exception& e) {
+        BOOST_LOG_TRIVIAL(warning) << "VendorCacheFile: rejecting vendor cache " << path << ": " << e.what();
+        return false;
+    }
+}
+
+// static
+std::string VendorCacheFile::peek_version(const std::string& path, const std::string& expected_vendor_name)
+{
+    try {
+        boost::nowide::ifstream ifs(path, std::ios::binary);
+        CacheFileHeader fhdr;
+        if (! ifs.read(reinterpret_cast<char*>(&fhdr), sizeof(fhdr)) || fhdr.magic != CACHE_MAGIC)
+            return {};
+        // Only the head of the body is read, and its CRC left unverified: the
+        // stamps sit at the front, and this answers "what version is this?"
+        // without paying for tens of megabytes. Callers that need to know the
+        // file is whole use usable_version instead.
+        std::string head(static_cast<size_t>(std::min<uint64_t>(fhdr.data_size, 1024)), '\0');
+        if (! ifs.read(&head[0], static_cast<std::streamsize>(head.size())))
+            return {};
+        std::istringstream body(head, std::ios::binary);
+        cereal::BinaryInputArchive ar(body);
+        return read_cache_stamps(ar, expected_vendor_name);
+    } catch (const std::exception&) {
+        return {};
+    }
+}
+
+// static
+Semver VendorCacheFile::usable_version(const std::string& path, const std::string& expected_vendor_name)
+{
+    std::string blob;
+    if (! read_cache_blob(path, blob))
+        return Semver::invalid();
+    try {
+        boost::iostreams::stream<boost::iostreams::array_source> body(blob.data(), blob.size());
+        cereal::BinaryInputArchive ar(body);
+        const auto ver = Semver::parse(read_cache_stamps(ar, expected_vendor_name));
+        return ver ? *ver : Semver::invalid();
+    } catch (const std::exception&) {
+        return Semver::invalid();
+    }
+}
+
+// static
+bool VendorCacheFile::carries_preset(const std::string& path, const std::string& vendor_name,
+                                     Preset::Type type, const std::string& preset_name)
+{
+    std::string blob;
+    if (! read_cache_blob(path, blob))
+        return false;
+    try {
+        boost::iostreams::stream<boost::iostreams::array_source> body(blob.data(), blob.size());
+        cereal::BinaryInputArchive ar(body);
+        if (read_cache_stamps(ar, vendor_name).empty())
+            return false;
+        CacheDictionary dict;
+        dict.load(ar);
+        VendorMap vendors;
+        ar(vendors);
+        // Reused: every entry overwrites it, and only its name is ever looked at.
+        CachedPreset entry;
+        // Written in this order by save. The list that could carry the preset
+        // is the last one worth reading.
+        for (Preset::Type kind : { Preset::TYPE_PRINT, Preset::TYPE_FILAMENT, Preset::TYPE_PRINTER }) {
+            uint32_t cnt = 0;
+            ar(cnt);
+            for (uint32_t i = 0; i < cnt; ++ i) {
+                visit_entry(ar, entry, [&] { skip_config(ar, dict); });
+                if (kind == type && entry.name == preset_name)
+                    return true;
+            }
+            if (kind == type)
+                return false;
+        }
+        return false;
+    } catch (const std::exception& e) {
+        BOOST_LOG_TRIVIAL(warning) << "VendorCacheFile: could not read preset names from " << path << ": " << e.what();
+        return false;
+    }
+}
+
+} // namespace Slic3r

src/libslic3r/PresetCacheFormat.hpp

@@ -0,0 +1,192 @@
+#ifndef slic3r_PresetCacheFormat_hpp_
+#define slic3r_PresetCacheFormat_hpp_
+
+#include <cstdint>
+#include <string>
+#include <unordered_map>
+#include <vector>
+
+#include <cereal/archives/binary.hpp>
+#include <cereal/types/string.hpp>
+#include <cereal/types/vector.hpp>
+
+#include "libslic3r/Config.hpp"
+#include "libslic3r/Preset.hpp"
+#include "libslic3r/PrintConfig.hpp"
+#include "libslic3r/Semver.hpp"
+
+namespace Slic3r {
+
+// How the preset cache writes a DynamicPrintConfig.
+//
+// Not through the global cereal hooks in PrintConfig.hpp: those key an option by
+// its serialization_key_ordinal, which ConfigDef::add assigns by declaration
+// order at static-init time. Inserting one option into the middle of
+// PrintConfig.cpp shifts every later ordinal, and the lookup on the way back in
+// then SUCCEEDS on the wrong option — where the two share a type, and hundreds
+// of coFloat/coBool/coInt options do, the bytes deserialize cleanly into the
+// wrong key. Silently wrong print settings, no error. Those hooks are also the
+// undo/redo wire format, where the process cannot change underneath them, so
+// they stay as they are and the cache keys by name instead.
+//
+// Names are not repeated per preset. Each cache file carries one dictionary of
+// the distinct opt_keys it uses, the type each was written as, and the distinct
+// enum value names; an option on the wire is then a uint16 index into it plus
+// its value. The dictionary is resolved to this build's option definitions once
+// per file, after which reading an option is a vector index.
+class CacheDictionary
+{
+public:
+    CacheDictionary();
+
+    // Index reserved in the enum table for an int the writing build could not
+    // name — a nullable option's nil, or a definition carrying no
+    // enum_keys_map. The raw int32 follows it on the wire and is loaded
+    // verbatim, so those values survive too.
+    static constexpr uint16_t ENUM_UNNAMED = 0;
+
+    // ---- writing ----
+
+    // Record every key and enum value `config` uses. Call for every config that
+    // will be written, before writing the dictionary.
+    void collect(const DynamicPrintConfig& config);
+
+    uint16_t key_index(const t_config_option_key& key) const;
+    // ENUM_UNNAMED for an empty name or one that was never collected.
+    uint16_t enum_index(const std::string& name) const;
+
+    // ---- reading ----
+
+    // The definition an index resolves to in THIS build, or nullptr where the
+    // key is unknown here or is now defined with a different type. A nullptr
+    // entry's value is still read — using type_at(idx), the type the writer
+    // recorded — and then dropped, which is what a JSON profile gets for an
+    // option this build no longer has.
+    const ConfigOptionDef* def_at(uint16_t idx) const { return m_defs[idx]; }
+    ConfigOptionType       type_at(uint16_t idx) const { return ConfigOptionType(m_types[idx]); }
+    const std::string&     enum_name_at(uint16_t idx) const { return m_enum_values[idx]; }
+    // m_defs, not m_keys: only load() sizes it, so this is false for every index
+    // on a dictionary that was collected rather than read.
+    bool valid_key_index(uint16_t idx) const { return size_t(idx) < m_defs.size(); }
+    bool valid_enum_index(uint16_t idx) const { return size_t(idx) < m_enum_values.size(); }
+
+    // The layout these two agree on is covered by CACHE_VERSION (PresetCacheFormat.cpp);
+    // bump it when they change.
+    // Throws when either table outgrew the uint16 the wire format indexes it
+    // with. Both are bounded by the option count (912 at the time of writing), so
+    // that is a build-time failure in CI, not a runtime one.
+    void save(cereal::BinaryOutputArchive& ar) const;
+    // Throws on a dictionary that cannot be indexed as written.
+    void load(cereal::BinaryInputArchive& ar);
+
+private:
+    // Indices are uint16, so a table may hold at most this many entries.
+    static constexpr size_t MAX_ENTRIES = 0xFFFF;
+
+    std::vector<std::string> m_keys;
+    // ConfigOptionType, as written. Sixteen bits, not eight: coVectorType is
+    // 0x4000, so every vector type — coFloats, coEnums, coStrings — is above
+    // 255, and a byte would fold each one onto its scalar counterpart.
+    std::vector<uint16_t>    m_types;
+    std::vector<std::string> m_enum_values;  // [ENUM_UNNAMED] is always empty
+
+    // Writing.
+    std::unordered_map<std::string, uint16_t> m_key_index;
+    std::unordered_map<std::string, uint16_t> m_enum_index;
+    // Reading, resolved once by load().
+    std::vector<const ConfigOptionDef*> m_defs;
+};
+
+// One config, keyed through `dict`. Options print_config_def does not know are
+// not written: nothing could give them a type on the way back in.
+void save_config(cereal::BinaryOutputArchive& ar, const DynamicPrintConfig& config, const CacheDictionary& dict);
+// Throws only on a payload that cannot be indexed; an option this build cannot
+// place is dropped, not fatal.
+void load_config(cereal::BinaryInputArchive& ar, DynamicPrintConfig& config, const CacheDictionary& dict);
+// Consume one config without building it, for a reader that only wants what
+// comes after.
+void skip_config(cereal::BinaryInputArchive& ar, const CacheDictionary& dict);
+
+// One preset as its JSON subfile states it: the config diff, the name of the
+// preset it inherits, and the parse metadata — everything the parse phase of
+// load_vendor_configs_from_json extracts and nothing it derives. Inheritance
+// is resolved when the entry is installed, against whatever filament library
+// is loaded then, so a cache carries no other vendor's values and no other
+// vendor's update can make it stale.
+// Written and read by visit_entry in PresetCacheFormat.cpp, which lists every
+// field below in this order — once, for the save, the load and the name peek alike.
+struct CachedPreset
+{
+    std::string              name;
+    std::string              sub_path;       // path under the vendor's directory
+    DynamicPrintConfig       config_src;     // the preset's own diff, nothing inherited
+    std::string              inherits;
+    std::string              description;
+    std::string              instantiation;  // "true"/"false" as stated; anything else was already counted as a parse error
+    std::string              setting_id;
+    std::string              filament_id;
+    std::vector<std::string> renamed_from;
+};
+
+// What one per-vendor cache file carries besides its stamps: the vendor profile
+// map, the presets in source form, and how many errors their parse counted.
+struct VendorCacheData
+{
+    VendorMap                 vendors;
+    std::vector<CachedPreset> process_entries;
+    std::vector<CachedPreset> filament_entries;
+    std::vector<CachedPreset> machine_entries;
+    uint64_t                  parse_errors = 0;
+};
+
+// A per-vendor preset cache file (<vendor>.opc): a 20-byte header (magic, format
+// version, body size, CRC) framing one cereal body — stamps (format version,
+// vendor name, vendor profile version), the option dictionary, then the
+// VendorCacheData. Everything about those bytes lives here; when a vendor is
+// served from its cache, and how entries install into a bundle, is
+// PresetBundle's business.
+class VendorCacheFile
+{
+public:
+    // Save one vendor (vendor_name at vendor_version). False when the file
+    // could not be written whole.
+    static bool save(const std::string& path, const std::string& vendor_name,
+                     const std::string& vendor_version, const VendorCacheData& data);
+
+    // Read a whole cache into `data`. False — with `data` in an unspecified
+    // state — unless the file is a cache this build wrote, its CRC holds, it
+    // names this vendor, it was built from a vendor profile at least as new as
+    // `expected_vendor_version`, and it carries its own vendor profile. An
+    // invalid expected version (a profile whose version
+    // cannot be judged) is never served from cache; Semver::inf() (no profile
+    // beside the cache at all) accepts whatever is cached.
+    static bool load(const std::string& path, const std::string& expected_vendor_name,
+                     const Semver& expected_vendor_version, VendorCacheData& data);
+
+    // Read the profile version a cache was stamped with, without deserializing
+    // its presets. Empty if the file is unreadable, not a cache this build
+    // understands, or not this vendor's. This is how an installed vendor's
+    // version is known when only its cache is installed.
+    static std::string peek_version(const std::string& path, const std::string& expected_vendor_name);
+
+    // The profile version an installed cache can actually be served at, or an
+    // invalid Semver when the file is not a cache this build can read. Unlike
+    // peek_version this verifies the body's CRC, at the cost of reading the
+    // whole file: where the cache is the vendor's whole installation, "a file
+    // is there" is not enough to call it installed, and a vendor wrongly
+    // believed installed is never repaired.
+    static Semver usable_version(const std::string& path, const std::string& expected_vendor_name);
+
+    // Whether a cache carries a preset of `type` under `preset_name`, without
+    // installing any of them. False when the file is not a cache this build can
+    // read. The three kinds are written in one stream, so reaching the machines
+    // means reading past the processes and filaments — their configs are consumed
+    // and dropped rather than built. This is how a build that ships caches instead
+    // of preset JSONs answers "which vendor carries this preset?".
+    static bool carries_preset(const std::string& path, const std::string& vendor_name,
+                               Preset::Type type, const std::string& preset_name);
+};
+
+} // namespace Slic3r
+
+#endif // slic3r_PresetCacheFormat_hpp_

src/libslic3r/Print.cpp

@@ -292,6 +292,14 @@ bool Print::invalidate_state_by_config_options(const ConfigOptionResolver & /* n
             || opt_key == "wipe_tower_x"
             || opt_key == "wipe_tower_y"
             || opt_key == "wipe_tower_rotation_angle") {
+            // The tower gcode itself is position-independent (position and rotation are applied
+            // at export), except that the wait_for_temp_on_wipe_tower park bakes a bed-relative
+            // side choice into it (WipeTower2::toolchange_Change) — regenerate it when the tower
+            // moves. Gating on the old config is safe: both inputs of wait_for_temp_enabled
+            // invalidate psWipeTower themselves when they are part of the same diff.
+            if ((opt_key == "wipe_tower_x" || opt_key == "wipe_tower_y" || opt_key == "wipe_tower_rotation_angle")
+                && WipeTower2::wait_for_temp_enabled(m_config))
+                steps.emplace_back(psWipeTower);
             steps.emplace_back(psSkirtBrim);
         } else if (
                opt_key == "slicing_pipeline_plugin"
@@ -412,6 +420,7 @@ bool Print::invalidate_state_by_config_options(const ConfigOptionResolver & /* n
             || opt_key == "wiping_volumes_extruders"
             || opt_key == "enable_filament_ramming"
             || opt_key == "tool_change_on_wipe_tower"
+            || opt_key == "wait_for_temp_on_wipe_tower"
             || opt_key == "purge_in_prime_tower"
             || opt_key == "z_offset"
             || opt_key == "support_multi_bed_types"
@@ -1093,13 +1102,14 @@ static StringObjectException layered_print_cleareance_valid(const Print &print,
             wipe_tower_convex_hull.points.emplace_back(scale_(x + width), scale_(y));
             wipe_tower_convex_hull.points.emplace_back(scale_(x + width), scale_(y + depth));
             wipe_tower_convex_hull.points.emplace_back(scale_(x), scale_(y + depth));
-            wipe_tower_convex_hull.rotate(a);
+            wipe_tower_convex_hull.rotate(Geometry::deg2rad(a), Point(scale_(x), scale_(y)));
             convex_hulls_temp.push_back(wipe_tower_convex_hull);
         } else {
             //here, wipe_tower_polygon is not always convex.
             Polygon wipe_tower_polygon;
             if (print.wipe_tower_data().wipe_tower_mesh_data)
                 wipe_tower_polygon = print.wipe_tower_data().wipe_tower_mesh_data->bottom;
+            wipe_tower_polygon.rotate(Geometry::deg2rad(a));
             wipe_tower_polygon.translate(Point(scale_(x), scale_(y)));
             convex_hulls_temp.push_back(wipe_tower_polygon);
         }
@@ -1118,6 +1128,22 @@ static StringObjectException layered_print_cleareance_valid(const Print &print,
     if (print_config.enable_wrapping_detection.value && !intersection({wrapping_poly}, convex_hulls_temp).empty()) {
         return {L("Prime Tower") + L(" is too close to clumping detection area, and collisions will be caused.\n")};
     }
+    // Skip the containment check for towers that will never be printed (single-filament
+    // prints without smooth timelapse keep the config's tower position but emit nothing).
+    // Pre-generation only the body square is tested — the auto-brim estimate can overshoot
+    // the generated brim by several mm and must not hard-fail a print that physically fits.
+    // Post-generation the mesh bottom already includes the real brim, so the exact
+    // footprint is tested.
+    if (filaments_count > 1 || print.enable_timelapse_print()) {
+        // The shared printable polygon is plate-local, while the tower polygons above are
+        // already shifted by the plate origin.
+        Polygons    printable_polys = print.get_extruder_shared_printable_polygon();
+        const Point plate_shift(scale_(plate_origin.x()), scale_(plate_origin.y()));
+        for (Polygon &p : printable_polys)
+            p.translate(plate_shift);
+        if (!diff(convex_hulls_temp, printable_polys).empty())
+            return {L("Prime Tower") + L(" is partially outside the printable area, and it cannot be printed.\n")};
+    }
     return {};
 }
 
@@ -4175,6 +4201,12 @@ const WipeTowerData &Print::wipe_tower_data(size_t filaments_cnt) const
         double volume = wipe_volume * filament_depth_count;
         if (m_config.nozzle_diameter.values.size() == 2) volume += filament_change_volume * (int) (filaments_cnt / 2);
 
+        // Sizing should take into account currently set wiping volumes.
+        // For a long time, the initial preview would just use 900/width per toolchange (15mm on a 60mm wide tower)
+        // and it worked well enough. Let's try to do slightly better by accounting for the purging volumes.
+        const bool semm_flush = m_config.purge_in_prime_tower && m_config.single_extruder_multi_material;
+        if (semm_flush) volume = WipeTower2::estimate_semm_flush_volume(m_config, filaments_cnt);
+
         if (m_config.wipe_tower_wall_type.value == WipeTowerWallType::wtwRib) {
             double depth = std::sqrt(volume / layer_height * extra_spacing);
             if (need_wipe_tower || filaments_cnt > 1) {
@@ -4186,30 +4218,16 @@ const WipeTowerData &Print::wipe_tower_data(size_t filaments_cnt) const
             }
         }
         else {
-        double width        = m_config.prime_tower_width;
-        if (m_config.purge_in_prime_tower && m_config.single_extruder_multi_material) {
-            // Calculating depth should take into account currently set wiping volumes.
-            // For a long time, the initial preview would just use 900/width per toolchange (15mm on a 60mm wide tower)
-            // and it worked well enough. Let's try to do slightly better by accounting for the purging volumes.
-            std::vector<std::vector<float>> wipe_volumes = WipeTower2::extract_wipe_volumes(m_config);
-            std::vector<float>              max_wipe_volumes;
-            for (const std::vector<float> &v : wipe_volumes)
-                max_wipe_volumes.emplace_back(*std::max_element(v.begin(), v.end()));
-            float maximum = std::accumulate(max_wipe_volumes.begin(), max_wipe_volumes.end(), 0.f);
-            maximum       = maximum * filaments_cnt / max_wipe_volumes.size();
-            
-            // Orca: it's overshooting a bit, so let's reduce it a bit
-            maximum *= 0.6; 
-            const_cast<Print *>(this)->m_wipe_tower_data.depth = maximum / (layer_height * width);
-        } else {
-            double depth = volume / (layer_height * width) * extra_spacing;
-            if (need_wipe_tower || m_wipe_tower_data.depth > EPSILON) {
+            double width = m_config.prime_tower_width;
+            double depth = volume / (layer_height * width);
+            // The flush volumes already hold the spacing between wipes.
+            if (!semm_flush) depth *= extra_spacing;
+            if (need_wipe_tower || depth > EPSILON) {
                 float min_wipe_tower_depth = WipeTower::get_limit_depth_by_height(max_height);
                 depth = std::max((double) min_wipe_tower_depth, depth);
             }
             const_cast<Print *>(this)->m_wipe_tower_data.depth = depth;
-        }
-        const_cast<Print *>(this)->m_wipe_tower_data.brim_width = m_config.prime_tower_brim_width;
+            const_cast<Print *>(this)->m_wipe_tower_data.brim_width = m_config.prime_tower_brim_width;
         }
         if (m_config.prime_tower_brim_width < 0) const_cast<Print *>(this)->m_wipe_tower_data.brim_width = WipeTower::get_auto_brim_by_height(max_height);
     }
@@ -6067,7 +6085,7 @@ BoundingBoxf3 PrintInstance::get_bounding_box() const {
 
 Polygon PrintInstance::get_convex_hull_2d() {
     Polygon poly = print_object->model_object()->convex_hull_2d(model_instance->get_matrix());
-    poly.douglas_peucker(0.1);
+    poly.douglas_peucker(scale_(0.1));
     return poly;
 }
 

src/libslic3r/Print.hpp

@@ -1001,8 +1001,8 @@ public:
     // If preview_data is not null, the preview_data is filled in for the G-code visualization (not used by the command line Slic3r).
     std::string         export_gcode(const std::string& path_template, GCodeProcessorResult* result, ThumbnailsGeneratorCallback thumbnail_cb = nullptr);
     //return 0 means successful
-    int                 export_cached_data(const std::string& dir_path, bool with_space=false);
-    int                 load_cached_data(const std::string& directory);
+    int                 export_cached_data(const std::string& dir_path, bool with_space=false) override;
+    int                 load_cached_data(const std::string& directory) override;
 
     // methods for handling state
     bool                is_step_done(PrintStep step) const { return Inherited::is_step_done(step); }

src/libslic3r/PrintConfig.cpp

@@ -74,6 +74,8 @@ const std::vector<std::string> filament_extruder_override_keys = {
     "filament_deretraction_speed",
     "filament_retract_restart_extra",  //not in filament_options_with_variant, added on 20250816
     "filament_retraction_minimum_travel",
+    "filament_retract_length_toolchange",
+    "filament_retract_restart_extra_toolchange",
     // BBS: floats
     "filament_wipe_distance",
     // bools
@@ -2029,6 +2031,13 @@ void PrintConfigDef::init_fff_params()
     def->mode = comAdvanced;
     def->set_default_value(new ConfigOptionFloat(1));
 
+    def = this->add("brim_ears_outer_only", coBool);
+    def->label = L("Brim ears outer only");
+    def->category = L("Support");
+    def->tooltip = L("Generate mouse ears only on the outer contour of the model, excluding holes and enclosed sections.");
+    def->mode = comAdvanced;
+    def->set_default_value(new ConfigOptionBool(false));
+
     def = this->add("compatible_printers", coStrings);
     def->label = L("Select printers");
     def->mode = comAdvanced;
@@ -3549,6 +3558,17 @@ void PrintConfigDef::init_fff_params()
     def->enum_labels.push_back(L("Octagram Spiral"));
     def->set_default_value(new ConfigOptionEnum<InfillPattern>(ipCrossHatch));
 
+    def = this->add("sparse_infill_smooth_factor", coPercent);
+    def->label = L("Sparse infill smooth factor");
+    def->category = L("Strength");
+    def->tooltip = L("Controls how strongly sparse infill corners are rounded. 0% keeps the original sharp path, "
+                     "while 100% produces the largest possible curves between adjacent infill lines.");
+    def->sidetext = "%";
+    def->min = 0;
+    def->max = 100;
+    def->mode = comAdvanced;
+    def->set_default_value(new ConfigOptionPercent(0));
+
     def = this->add("top_surface_acceleration", coFloats);
     def->label = L("Top surface");
     def->category = L("Speed");
@@ -4332,6 +4352,15 @@ void PrintConfigDef::init_fff_params()
     def->readonly = false;
     def->set_default_value(new ConfigOptionEnum<GCodeFlavor>(gcfMarlinLegacy));
 
+    def = this->add("gcode_skip_config_block", coBool);
+    def->label = L("Skip G-code config block");
+    def->tooltip = L("Do not write the CONFIG_BLOCK (slicer configuration key/value pairs) into the G-code file. "
+                   "This can help with printers whose firmware crashes when parsing these comment lines "
+                   "(e.g. Anycubic go-klipper). Note: the G-code file will no longer contain slicer settings, "
+                   "so importing it back into OrcaSlicer will not restore the configuration.");
+    def->mode = comAdvanced;
+    def->set_default_value(new ConfigOptionBool(false));
+
     def          = this->add("pellet_modded_printer", coBool);
     def->label   = L("Pellet Modded Printer");
     def->tooltip = L("Enable this option if your printer uses pellets instead of filaments.");
@@ -4365,7 +4394,7 @@ void PrintConfigDef::init_fff_params()
                    "slow down.");
     def->mode = comAdvanced;
     def->set_default_value(new ConfigOptionBool(0));
-    
+
     //BBS
     def = this->add("infill_combination", coBool);
     def->label = L("Infill combination");
@@ -5798,12 +5827,10 @@ void PrintConfigDef::init_fff_params()
     def->set_default_value(new ConfigOptionFloatsNullable{10});
 
     def = this->add("retract_length_toolchange", coFloats);
-    def->label = L("Length");
-    //def->full_label = L("Retraction Length (Toolchange)");
-    def->full_label = "Retraction Length (Toolchange)";
-    //def->tooltip = L("When retraction is triggered before changing tool, filament is pulled back "
-    //               "by the specified amount (the length is measured on raw filament, before it enters "
-    //               "the extruder).");
+    def->label = L("Retraction Length (Toolchange)");
+    def->tooltip = L("When retraction is triggered before changing tool, filament is pulled back "
+                  "by the specified amount (the length is measured on raw filament, before it enters "
+                  "the extruder).");
     def->sidetext = L("mm");	// millimeters, CIS languages need translation
     def->mode = comAdvanced;
     def->set_default_value(new ConfigOptionFloats { 10. });
@@ -6057,7 +6084,7 @@ void PrintConfigDef::init_fff_params()
     def->set_default_value(new ConfigOptionFloats { 0. });
 
     def = this->add("retract_restart_extra_toolchange", coFloats);
-    def->label = L("Extra length on restart");
+    def->label = L("Extra length on restart (Toolchange)");
     def->tooltip = L("When the retraction is compensated after changing tool, the extruder will push "
                   "this additional amount of filament.");
     def->sidetext = L("mm");	// millimeters, CIS languages need translation
@@ -6634,6 +6661,17 @@ void PrintConfigDef::init_fff_params()
     def->mode = comAdvanced;
     def->set_default_value(new ConfigOptionBool(false));
 
+    def = this->add("wait_for_temp_on_wipe_tower", coBool);
+    def->label = L("Wait for temperature on wipe tower");
+    def->tooltip = L("Pick up the new tool without waiting for it to reach printing temperature, travel to the wipe "
+                     "tower, and wait for the temperature there, right before purging. Ooze from the heat-up lands on "
+                     "the tower instead of the model, and the travel overlaps with the heating. "
+                     "Only relevant for multi-extruder (multi-toolhead) printers using a Type 2 wipe tower. "
+                     "The firmware or tool change macro must not wait for the temperature itself. "
+                     "When disabled, the temperature wait is issued right after the tool change command.");
+    def->mode = comAdvanced;
+    def->set_default_value(new ConfigOptionBool(false));
+
 
     def = this->add("wipe_tower_no_sparse_layers", coBool);
     def->label = L("No sparse layers (beta)");
@@ -8528,10 +8566,12 @@ void PrintConfigDef::init_extruder_option_keys()
         "long_retractions_when_cut",
         "retract_after_wipe",
         "retract_before_wipe",
+        "retract_length_toolchange",
         "retract_lift_above",
         "retract_lift_below",
         "retract_lift_enforce",
         "retract_restart_extra",
+        "retract_restart_extra_toolchange",
         "retract_when_changing_layer",
         "retraction_distances_when_cut",
         "retraction_length",
@@ -9619,6 +9659,8 @@ std::set<std::string> filament_options_with_variant = {
     "filament_retract_lift_below",
     "filament_retract_lift_enforce",
     "filament_retract_restart_extra",
+    "filament_retract_length_toolchange",
+    "filament_retract_restart_extra_toolchange",
     "filament_retraction_speed",
     "filament_deretraction_speed",
     "filament_retraction_minimum_travel",
@@ -10776,6 +10818,16 @@ int DynamicPrintConfig::update_values_from_multi_to_multi_2(const std::vector<st
 
 }
 
+void set_variant_override(ConfigOptionVectorBase &target, const ConfigOptionVectorBase &source,
+                          const std::vector<int> &variant_index, int stride)
+{
+    // A single-value object or region override applies to every nozzle variant.
+    std::vector<int> indices = variant_index;
+    if (source.size() == 1 && !source.is_nil(0))
+        std::fill(indices.begin(), indices.end(), 0);
+    target.set_to_index(&source, indices, stride);
+}
+
 
 //used for object/region config
 //use the smallest of multiple to single
@@ -11853,7 +11905,7 @@ void update_static_print_config_from_dynamic(ConfigBase& config, const DynamicPr
                 else {
                     ConfigOptionVectorBase* opt_vec_src = static_cast<ConfigOptionVectorBase*>(opt_src);
                     const ConfigOptionVectorBase* opt_vec_dest = static_cast<const ConfigOptionVectorBase*>(opt_dest);
-                    opt_vec_src->set_to_index(opt_vec_dest, variant_index, stride);
+                    set_variant_override(*opt_vec_src, *opt_vec_dest, variant_index, stride);
                 }
             }
         }

src/libslic3r/PrintConfig.hpp

@@ -146,6 +146,29 @@ inline bool is_separable_infill_pattern(InfillPattern pattern)
     }
 }
 
+// Orca: Infill patterns that round their corners by the "sparse_infill_smooth_factor" option.
+// Grid, Triangles and Tri-hexagon only do so in their trapezoidal form, which is generated with more
+// than one line per infill wall; a single line makes them plain crossing lines with nothing to round.
+inline bool is_smoothable_infill_pattern(InfillPattern pattern, int multiline = 1)
+{
+    switch (pattern) {
+    case ipHilbertCurve:
+    case ipOctagramSpiral:
+    case ipLightning:
+    case ipHoneycomb:
+    case ip3DHoneycomb:
+    case ipConcentric:
+    case ipCrossHatch:
+        return true;
+    case ipGrid:
+    case ipTriangles:
+    case ipStars:
+        return multiline > 1;
+    default:
+        return false;
+    }
+}
+
 enum class IroningType {
     NoIroning,
     TopSurfaces,
@@ -906,6 +929,9 @@ extern std::set<std::string> printer_options_with_variant_1;
 extern std::set<std::string> printer_options_with_variant_2;
 extern std::set<std::string> empty_options;
 
+void set_variant_override(ConfigOptionVectorBase &target, const ConfigOptionVectorBase &source,
+                          const std::vector<int> &variant_index, int stride = 1);
+
 extern std::set<std::string> filament_dev_options;
 
 extern void update_static_print_config_from_dynamic(ConfigBase& config, const DynamicPrintConfig& dest_config, std::vector<int> variant_index, std::set<std::string>& key_set1, int stride = 1);
@@ -1148,6 +1174,7 @@ PRINT_CONFIG_CLASS_DEFINE(
     ((ConfigOptionFloat,               extra_brim_width))
     ((ConfigOptionFloat,               brim_ears_detection_length))
     ((ConfigOptionFloat,               brim_ears_max_angle))
+    ((ConfigOptionBool,                brim_ears_outer_only))
     ((ConfigOptionFloat,               skirt_start_angle))
     ((ConfigOptionBool,                bridge_no_support))
     ((ConfigOptionFloat,               elefant_foot_compensation))
@@ -1333,6 +1360,7 @@ PRINT_CONFIG_CLASS_DEFINE(
     ((ConfigOptionString,               sparse_infill_rotate_template))
     ((ConfigOptionPercent,              sparse_infill_density))
     ((ConfigOptionEnum<InfillPattern>,  sparse_infill_pattern))
+    ((ConfigOptionPercent,              sparse_infill_smooth_factor))
     ((ConfigOptionFloat,                lateral_lattice_angle_1))
     ((ConfigOptionFloat,                lateral_lattice_angle_2))
     ((ConfigOptionFloat,                infill_overhang_angle))
@@ -1614,7 +1642,7 @@ PRINT_CONFIG_CLASS_DEFINE(
     ((ConfigOptionBool,                gcode_add_line_number))
     ((ConfigOptionBool,                bbl_bed_temperature_gcode))
     ((ConfigOptionEnum<GCodeFlavor>,   gcode_flavor))
-
+    ((ConfigOptionBool,                gcode_skip_config_block))
     ((ConfigOptionFloat,               time_cost)) 
     ((ConfigOptionString,              layer_change_gcode))
     ((ConfigOptionString,              time_lapse_gcode))
@@ -1727,6 +1755,7 @@ PRINT_CONFIG_CLASS_DEFINE(
     ((ConfigOptionBool,                purge_in_prime_tower))
     ((ConfigOptionBool,                enable_filament_ramming))
     ((ConfigOptionBool,                tool_change_on_wipe_tower))
+    ((ConfigOptionBool,                wait_for_temp_on_wipe_tower))
     ((ConfigOptionBool,                support_multi_bed_types))
     ((ConfigOptionBool,                use_3mf))
 
@@ -2499,6 +2528,55 @@ static void set_flush_volumes_matrix(std::vector<T> &out_matrix, const std::vect
     }
 }
 
+template<class T>
+static bool has_zero_flush_volume_for_used_filaments(const std::vector<T> &fv_matrix,
+                                                      const std::vector<T> &flush_multipliers,
+                                                      const std::vector<int> &used_filaments)
+{
+    if (used_filaments.size() < 2 || flush_multipliers.empty())
+        return false;
+
+    if (fv_matrix.size() % flush_multipliers.size() != 0)
+        return false;
+
+    const size_t matrix_len = fv_matrix.size() / flush_multipliers.size();
+    const size_t row_len    = size_t(std::sqrt(double(matrix_len)));
+    if (row_len < 2 || row_len * row_len != matrix_len)
+        return false;
+
+    std::vector<int> filtered_filaments;
+    filtered_filaments.reserve(used_filaments.size());
+    for (int filament_id : used_filaments) {
+        if (filament_id <= 0 || filament_id > int(row_len))
+            continue;
+        if (std::find(filtered_filaments.begin(), filtered_filaments.end(), filament_id) == filtered_filaments.end())
+            filtered_filaments.push_back(filament_id);
+    }
+    if (filtered_filaments.size() < 2)
+        return false;
+
+    for (T multiplier : flush_multipliers) {
+        if (multiplier == 0)
+            return true;
+    }
+
+    for (size_t nozzle_idx = 0; nozzle_idx < flush_multipliers.size(); nozzle_idx++) {
+        const size_t block_offset = nozzle_idx * matrix_len;
+        for (int from_id : filtered_filaments) {
+            for (int to_id : filtered_filaments) {
+                if (from_id == to_id)
+                    continue;
+
+                const size_t matrix_idx = block_offset + size_t(from_id - 1) * row_len + size_t(to_id - 1);
+                if (matrix_idx < fv_matrix.size() && fv_matrix[matrix_idx] == 0)
+                    return true;
+            }
+        }
+    }
+
+    return false;
+}
+
 size_t get_extruder_index(const GCodeConfig& config, unsigned int filament_id);
 
 } // namespace Slic3r
@@ -2518,7 +2596,8 @@ namespace cereal {
             archive(serialization_key_ordinal);
             assert(serialization_key_ordinal > 0);
             auto it = Slic3r::print_config_def.by_serialization_key_ordinal.find(serialization_key_ordinal);
-            assert(it != Slic3r::print_config_def.by_serialization_key_ordinal.end());
+            if (it == Slic3r::print_config_def.by_serialization_key_ordinal.end())
+                throw std::runtime_error("VendorCache: unknown serialization_key_ordinal " + std::to_string(serialization_key_ordinal) + " - cache is stale");
             config.set_key_value(it->second->opt_key, it->second->load_option_from_archive(archive));
         }
     }

src/libslic3r/PrintObject.cpp

@@ -1290,6 +1290,7 @@ bool PrintObject::invalidate_state_by_config_options(
             || opt_key == "brim_type"
             || opt_key == "brim_ears_max_angle"
             || opt_key == "brim_ears_detection_length"
+            || opt_key == "brim_ears_outer_only"
             // BBS: brim generation depends on printing speed
             || opt_key == "outer_wall_speed"
             || opt_key == "small_perimeter_speed"
@@ -1524,6 +1525,7 @@ bool PrintObject::invalidate_state_by_config_options(
             || opt_key == "infill_overhang_angle") {
             steps.emplace_back(posInfill);
         } else if (opt_key == "sparse_infill_pattern"
+                   || opt_key == "sparse_infill_smooth_factor"
                    || opt_key == "symmetric_infill_y_axis"
                    || opt_key == "infill_shift_step"
                    || opt_key == "sparse_infill_rotate_template"
@@ -3933,7 +3935,7 @@ static void apply_to_print_region_config(PrintRegionConfig &out, const DynamicPr
                         else {
                             ConfigOptionVectorBase* opt_vec_src = static_cast<ConfigOptionVectorBase*>(my_opt);
                             const ConfigOptionVectorBase* opt_vec_dest = static_cast<const ConfigOptionVectorBase*>(it->second.get());
-                            opt_vec_src->set_to_index(opt_vec_dest, variant_index, 1);
+                            set_variant_override(*opt_vec_src, *opt_vec_dest, variant_index);
                         }
                     }
                 }

src/libslic3r/SLA/IndexedMesh.cpp

@@ -56,12 +56,12 @@ public:
                             int &                        i,
                             Eigen::Matrix<double, 1, 3> &closest)
     {
-        size_t idx_unsigned = 0;
-        Vec3d  closest_vec3d(closest);
-        double dist =
+        size_t idx_unsigned { 0 };
+        Vec3d  closest_vec3d { Vec3d::Zero() };
+        const double dist {
             AABBTreeIndirect::squared_distance_to_indexed_triangle_set(
                 its.vertices, its.indices, m_tree, point, idx_unsigned,
-                closest_vec3d);
+                closest_vec3d) };
         i       = int(idx_unsigned);
         closest = closest_vec3d;
         return dist;

src/libslic3r/SLA/SupportTreeBuilder.cpp

@@ -1,4 +1,6 @@
+#ifndef NOMINMAX
 #define NOMINMAX
+#endif
 
 #include <libslic3r/SLA/SupportTreeBuilder.hpp>
 #include <libslic3r/SLA/SupportTreeBuildsteps.hpp>

src/libslic3r/Semver.hpp

@@ -190,6 +190,19 @@ public:
 		os << self.to_string();
 		return os;
 	}
+
+	// cereal: round-trip through the standard 3-part string (major.minor.patch).
+	// to_string() uses a BBS 4-part format that semver_parse() cannot read back.
+	template<class Archive>
+	std::string save_minimal(const Archive&) const { return to_string_sf(); }
+	template<class Archive>
+	void load_minimal(const Archive&, const std::string& s) {
+		auto v = Semver::parse(s);
+		if (! v)
+			throw std::runtime_error("Semver: cannot parse serialized version: " + s);
+		*this = std::move(*v);
+	}
+
 private:
 	semver_t ver;
 

src/libslic3r/Technologies.hpp

@@ -51,9 +51,4 @@
 // Enable extension of tool position imgui dialog to show actual speed profile
 #define ENABLE_ACTUAL_SPEED_DEBUG 1
 
-// Disable layout inspector for public release
-#if BBL_RELEASE_TO_PUBLIC
-#define WXINSPECTOR_DISABLE
-#endif
-
 #endif // _prusaslicer_technologies_h_

src/libslic3r/TriangleMeshSlicer.cpp

@@ -1499,6 +1499,13 @@ static std::vector<Polygons> make_loops(
                 Polygons &polygons = layers[line_idx];
                 polygons = make_loops(lines[line_idx]);
 
+                // Orca: A planar quad represented by two triangles contributes a point where the
+                // slicing plane crosses the shared diagonal. After rounding to coord_t this
+                // point may be very slightly off the otherwise straight contour edge. Apart
+                // from being redundant, such points make the subsequent contour
+                // simplification depend on the slice height (and may move seam candidates).
+                remove_collinear(polygons);
+
                 auto this_mode = line_idx < params.slicing_mode_normal_below_layer ? params.mode_below : params.mode;
                 if (! polygons.empty()) {
                     if (this_mode == MeshSlicingParams::SlicingMode::Positive) {

src/libslic3r/Utils.hpp

@@ -3,6 +3,7 @@
 
 #include <iomanip>
 #include <locale>
+#include <set>
 #include <utility>
 #include <functional>
 #include <type_traits>
@@ -18,6 +19,7 @@
 #include <openssl/md5.h>
 
 #include "libslic3r.h"
+#include "Semver.hpp"
 
 //define CLI errors
 
@@ -722,11 +724,42 @@ void copy_directory_recursively(const boost::filesystem::path& source,
                                 std::function<bool(const std::string)> filter = nullptr,
                                 bool merge_mode                               = false);
 
-// Install vendor bundles from resources directory to data directory
-// bundle_names: vector of vendor bundle names (without .json extension)
-// resource_subdir: subdirectory under resources_dir() (default: "profiles")
-// data_subdir: subdirectory under data_dir() (default: "system")
-// Returns: true if all bundles installed successfully, false otherwise
+// ---- Vendor installation on disk ------------------------------------------
+// How a vendor bundle is installed from resources into data_dir()/system: as
+// its profile and preset JSONs or, in a build that ships preset caches, as its
+// .opc preset cache alone. Loading what is installed is PresetBundle's business;
+// the cache file format itself is VendorCacheFile's (PresetCacheFormat.hpp).
+
+// True if `vendor` is installed in data_dir()/system. A build that ships preset
+// caches installs the cache alone, so it — not the profile — marks a vendor
+// installed; a cache this build cannot read marks nothing.
+bool is_vendor_installed(const std::string& vendor);
+
+// The version the installed vendor would be loaded at: its cache's stamp while
+// that covers the profile beside it, the profile's own version once it does not.
+// Invalid Semver if neither form is installed.
+Semver installed_vendor_version(const std::string& vendor);
+
+// Remove every form `vendor` can be installed as from data_dir()/system: its
+// profile, its preset cache, and its preset directory.
+void remove_installed_vendor(const std::string& vendor);
+
+// The vendors `dir` holds, sorted: one is named by its profile or, in a build that
+// ships preset caches instead of the raw profile JSONs, by its cache alone.
+std::set<std::string> vendor_names_in(const boost::filesystem::path& dir);
+
+// The version a build ships `vendor` at: whichever of its preset cache and its
+// profile is newer, that being the one installing lays down. Invalid Semver if the
+// build ships neither.
+Semver resource_vendor_version(const std::string& vendor);
+
+// Install vendors from the resources directory into the data directory, each as
+// its preset cache or as its profile and preset JSONs — whichever of the two the
+// build ships at the newer version. Anything the previous install of that vendor
+// left behind goes, so only the form just installed is there to be loaded.
+// bundle_names: vendor names, without extension.
+// Every bundle that can be installed is, whatever the others do. Returns false
+// if any named bundle could not be installed.
 bool install_vendor_bundles_from_resources(const std::vector<std::string>& bundle_names,
                                            const std::string& resource_subdir = "profiles",
                                            const std::string& data_subdir     = "system");

src/libslic3r/utils.cpp

@@ -17,6 +17,10 @@
 #include "Platform.hpp"
 #include "Time.hpp"
 #include "libslic3r.h"
+// For the vendor-installation helpers: the vendor profile version
+// (get_version_from_json) and the preset cache stamp (VendorCacheFile).
+#include "Preset.hpp"
+#include "PresetCacheFormat.hpp"
 
 #ifdef __APPLE__
 #include "MacUtils.hpp"
@@ -1724,6 +1728,85 @@ void copy_directory_recursively(const boost::filesystem::path& source,
     return;
 }
 
+// ---- Vendor installation on disk ------------------------------------------
+
+// Whether a cache stamped `cache_ver` still speaks for a vendor whose profile on
+// disk claims `profile_ver`: it does unless the profile has moved ahead of it. A
+// profile that is missing or carries no judgeable version cannot be ahead of
+// anything. The one rule behind both "which form gets installed" and "which form
+// is installed"; they must not drift apart. Deliberately NOT the serve rule
+// (VendorCacheFile::load), which refuses an unjudgeable profile instead.
+static bool cache_covers(const Semver& cache_ver, const Semver& profile_ver)
+{
+    return cache_ver.valid() && (! profile_ver.valid() || cache_ver >= profile_ver);
+}
+
+bool is_vendor_installed(const std::string& vendor)
+{
+    const boost::filesystem::path dir = boost::filesystem::path(data_dir()) / PRESET_SYSTEM_DIR;
+    // A cache is the whole of a cache-only installation, so a file this build
+    // cannot serve the vendor from is not an installation. Left counted as one,
+    // the updater would never lay a working copy down.
+    return boost::filesystem::exists(dir / (vendor + ".json"))
+        || VendorCacheFile::usable_version((dir / (vendor + ".opc")).string(), vendor).valid();
+}
+
+Semver installed_vendor_version(const std::string& vendor)
+{
+    const boost::filesystem::path dir  = boost::filesystem::path(data_dir()) / PRESET_SYSTEM_DIR;
+    const boost::filesystem::path json = dir / (vendor + ".json");
+    // Guarded: get_version_from_json logs an error and throws-and-catches its way
+    // to an invalid version on a file that is not there, and a cache-only vendor
+    // never has one.
+    const Semver from_json  = boost::filesystem::exists(json) ? get_version_from_json(json.string()) : Semver();
+    const Semver from_cache = VendorCacheFile::usable_version((dir / (vendor + ".opc")).string(), vendor);
+    // Whichever form a load would serve.
+    return cache_covers(from_cache, from_json) ? from_cache : from_json;
+}
+
+void remove_installed_vendor(const std::string& vendor)
+{
+    const boost::filesystem::path dir = boost::filesystem::path(data_dir()) / PRESET_SYSTEM_DIR;
+    boost::filesystem::remove(dir / (vendor + ".json"));
+    boost::filesystem::remove(dir / (vendor + ".opc"));
+    if (boost::filesystem::exists(dir / vendor))
+        boost::filesystem::remove_all(dir / vendor);
+}
+
+std::set<std::string> vendor_names_in(const boost::filesystem::path& dir)
+{
+    std::set<std::string> names;
+    for (auto& dir_entry : boost::filesystem::directory_iterator(dir)) {
+        const auto& path = dir_entry.path();
+        if (Slic3r::is_json_file(path.string()) || path.extension() == ".opc")
+            names.insert(path.stem().string());
+    }
+    return names;
+}
+
+// A vendor's preset cache is the whole of its installation: it carries the presets,
+// the vendor profile and the version they were built at, so where one ships nothing
+// else needs copying. Unless the profile beside it claims a newer version — a cache
+// generated before that profile was bumped is out of date, and a cache that cannot
+// be read is no installation at all — and the vendor is installed the way it was
+// before caches existed, as its profile and the preset JSONs it points at. Returns
+// the version the cache is stamped with, invalid when it is not the form to install.
+static Semver installable_cache_version(const boost::filesystem::path& dir, const std::string& vendor)
+{
+    const auto cache_ver = Semver::parse(VendorCacheFile::peek_version((dir / (vendor + ".opc")).string(), vendor));
+    if (! cache_ver)
+        return Semver::invalid();
+    const Semver profile_ver = get_version_from_json((dir / (vendor + ".json")).string());
+    return cache_covers(*cache_ver, profile_ver) ? *cache_ver : Semver::invalid();
+}
+
+Semver resource_vendor_version(const std::string& vendor)
+{
+    const boost::filesystem::path dir = boost::filesystem::path(resources_dir()) / "profiles";
+    const Semver ver = installable_cache_version(dir, vendor);
+    return ver.valid() ? ver : get_version_from_json((dir / (vendor + ".json")).string());
+}
+
 bool install_vendor_bundles_from_resources(
     const std::vector<std::string>& bundle_names,
     const std::string& resource_subdir,
@@ -1736,37 +1819,82 @@ bool install_vendor_bundles_from_resources(
 
     BOOST_LOG_TRIVIAL(info) << "Installing " << bundle_names.size() << " bundles from resources...";
 
+    // One vendor that cannot be installed is one vendor missing, not a reason to
+    // leave the rest uninstalled. The caller is told, and every bundle that can
+    // be laid down is.
+    bool all_installed = true;
+
     for (const auto &bundle : bundle_names) {
         try {
+            if (bundle.empty()) {
+                BOOST_LOG_TRIVIAL(warning) << "Refusing to install a bundle with no name";
+                all_installed = false;
+                continue;
+            }
+
             // Install the JSON file
             auto path_in_rsrc = (rsrc_path / bundle).replace_extension(".json");
             auto path_in_vendors = (vendor_path / bundle).replace_extension(".json");
+            auto cache_in_rsrc = (rsrc_path / bundle).replace_extension(".opc");
+            auto cache_in_vendors = (vendor_path / bundle).replace_extension(".opc");
 
-            if (!fs::exists(path_in_rsrc)) {
+            // Either form of the vendor will do: a build may ship it as a cache alone.
+            if (!fs::exists(path_in_rsrc) && !fs::exists(cache_in_rsrc)) {
                 BOOST_LOG_TRIVIAL(warning) << "Bundle not found in resources: " << bundle;
-                return false;
+                all_installed = false;
+                continue;
             }
 
             // Create target directory if needed
             if (!fs::exists(vendor_path))
                 fs::create_directories(vendor_path);
 
-            // Copy JSON file
             std::string error_message;
-            CopyFileResult cfr = copy_file(path_in_rsrc.string(), path_in_vendors.string(), error_message, false);
-            if (cfr != CopyFileResult::SUCCESS) {
-                BOOST_LOG_TRIVIAL(error) << "Failed to copy " << bundle << ".json: " << error_message;
-                return false;
+            bool installed_cache = false;
+            if (installable_cache_version(rsrc_path, bundle).valid()) {
+                installed_cache = copy_file(cache_in_rsrc.string(), cache_in_vendors.string(), error_message, false) == CopyFileResult::SUCCESS;
+                if (! installed_cache) {
+                    BOOST_LOG_TRIVIAL(warning) << "Failed to copy " << bundle << ".opc: " << error_message;
+                } else if (! VendorCacheFile::usable_version(cache_in_vendors.string(), bundle).valid()) {
+                    // The copy is what will be loaded, so it — not the kilobyte
+                    // peek that chose this form — decides whether the profile
+                    // beside it can go.
+                    BOOST_LOG_TRIVIAL(warning) << "Installed cache for " << bundle << " cannot be read; installing its profile instead";
+                    boost::system::error_code ec;
+                    fs::remove(cache_in_vendors, ec);
+                    installed_cache = false;
+                }
+            }
+
+            if (! installed_cache) {
+                CopyFileResult cfr = copy_file(path_in_rsrc.string(), path_in_vendors.string(), error_message, false);
+                if (cfr != CopyFileResult::SUCCESS) {
+                    BOOST_LOG_TRIVIAL(error) << "Failed to copy " << bundle << ".json: " << error_message;
+                    all_installed = false;
+                    continue;
+                }
+                // Only now: an earlier install's cache would shadow this profile,
+                // but removing it before the profile lands would leave neither.
+                boost::system::error_code ec;
+                fs::remove(cache_in_vendors, ec);
+            } else {
+                // Left in place, an earlier install's profile would shadow the cache.
+                boost::system::error_code ec;
+                fs::remove(path_in_vendors, ec);
+                if (ec)
+                    BOOST_LOG_TRIVIAL(warning) << "Could not remove the superseded profile " << path_in_vendors.string() << ": " << ec.message();
             }
 
             // Copy the vendor directory (if it exists)
             auto dir_in_rsrc = rsrc_path / bundle;
             auto dir_in_vendors = vendor_path / bundle;
 
-            if (fs::exists(dir_in_rsrc) && fs::is_directory(dir_in_rsrc)) {
-                // Remove existing directory
-                if (fs::exists(dir_in_vendors))
-                    fs::remove_all(dir_in_vendors);
+            // Whatever is installed came from an earlier version of this vendor and
+            // would be parsed in place of the one being installed now.
+            if (fs::exists(dir_in_vendors))
+                fs::remove_all(dir_in_vendors);
+
+            if (! installed_cache && fs::exists(dir_in_rsrc) && fs::is_directory(dir_in_rsrc)) {
                 fs::create_directories(dir_in_vendors);
 
                 // Copy with file filter (same as PresetUpdater::install_bundles_rsrc)
@@ -1787,11 +1915,11 @@ bool install_vendor_bundles_from_resources(
 
         } catch (const std::exception& e) {
             BOOST_LOG_TRIVIAL(error) << "Exception installing bundle " << bundle << ": " << e.what();
-            return false;
+            all_installed = false;
         }
     }
 
-    return true;
+    return all_installed;
 }
 
 void save_string_file(const boost::filesystem::path& p, const std::string& str)