Files
OrcaSlicer/tests/fff_print/test_skirt_brim.cpp
harrierpigeon a453cb1eba tests: cover belt-brim first-contact emission, tool selection, inner/leading-edge, and predicate (E)
Deterministic tests for: coincident brim at first belt contact not dropped
(C), single- and multi-extruder brim tool selection with no doubling (B),
multi-object apron ordering, inner-only+leading-only not rejecting prime
tower/spiral (D), and inner/holed + leading-edge-only geometry.
2026-08-06 15:40:04 -05:00

1037 lines
43 KiB
C++

#include <catch2/catch_all.hpp>
#include "libslic3r/ClipperUtils.hpp"
#include "libslic3r/GCodeReader.hpp"
#include "libslic3r/Layer.hpp"
#include "libslic3r/Config.hpp"
#include "libslic3r/Geometry.hpp"
#include "libslic3r/Geometry/ConvexHull.hpp"
#include <boost/algorithm/string.hpp>
#include <cctype>
#include <cmath>
#include <limits>
#include <map>
#include <set>
#include <string>
#include "test_helpers.hpp" // get access to init_print, etc
using namespace Slic3r::Test;
using namespace Slic3r;
// Distinct brim regions (combine_brims merges touching brims into one covering >1 object).
static int brim_count(const Print &print)
{
int n = 0;
for (const auto &group : print.skirt_brim_groups())
n += (int) group.brims.size();
return n;
}
// Total brim loops across all objects.
static size_t brim_loop_count(Print &print)
{
size_t n = 0;
for (const auto &kv : print.get_brimMap())
n += kv.second.items_count();
return n;
}
// The span is skirt_height layers, or every layer when a draft shield is on (forced even at
// height 0); per-object skirts are rejected in By object printing (no room between objects).
TEST_CASE("Skirt is emitted once per layer it spans", "[SkirtBrim]")
{
const int object_layers = 100; // 20mm cube at 0.2mm layers
const char *skirt_type = GENERATE("combined", "perobject");
const char *print_seq = GENERATE("by layer", "by object");
const char *draft_shield = GENERATE("disabled", "enabled");
const int skirt_height = GENERATE(0, 1, 3);
DYNAMIC_SECTION(skirt_type << " | " << print_seq << " | draft=" << draft_shield << " | height=" << skirt_height) {
auto do_slice = [&] {
return slice_two_cubes_arranged({
{ "skirt_loops", 1 },
{ "skirt_height", skirt_height },
{ "skirt_distance", 3 },
{ "skirt_type", skirt_type },
{ "draft_shield", draft_shield },
{ "print_sequence", print_seq },
{ "layer_height", 0.2 },
});
};
const bool draft = std::string(draft_shield) == "enabled";
const bool has_skirt = draft || skirt_height > 0;
const bool unsafe_by_object = std::string(skirt_type) == "perobject"
&& std::string(print_seq) == "by object" && has_skirt;
if (unsafe_by_object) {
REQUIRE_THROWS(do_slice());
} else {
const int expected_layers = draft ? object_layers : skirt_height;
CHECK(role_passes(do_slice(), "skirt") == expected_layers);
}
}
}
// Each per-object skirt prints right before its own object, so distant objects yield two
// non-contiguous skirt passes; close objects group into a single skirt.
TEST_CASE("Per-object skirts group when objects are close", "[SkirtBrim]")
{
auto [gap, expected_skirts] = GENERATE(table<double, int>({ { 5.0, 1 }, { 60.0, 2 } }));
DYNAMIC_SECTION("gap=" << gap) {
const std::string gcode = slice_two_cubes_apart(gap, {
{ "skirt_loops", 1 },
{ "skirt_height", 1 },
{ "skirt_distance", 3 },
{ "skirt_type", "perobject" },
{ "print_sequence", "by layer" },
{ "layer_height", 0.2 },
});
CHECK(role_passes(gcode, "skirt") == expected_skirts);
}
}
TEST_CASE("Per-object skirt is generated per instance", "[SkirtBrim]")
{
Print print;
Model model;
place_two_cube_instances_apart(60, {
{ "skirt_type", "perobject" },
{ "skirt_height", 1 },
{ "skirt_distance", 2 },
{ "skirt_loops", 1 },
{ "brim_type", "no_brim" },
}, print, model);
print.process();
REQUIRE(print.skirt_brim_groups().size() == 2);
REQUIRE(print.skirt().items_count() == 2);
for (const Print::SkirtBrimGroup &group : print.skirt_brim_groups()) {
REQUIRE(group.instances.size() == 1);
REQUIRE(group.instances.front().object_id == print.get_object(0)->id());
}
}
TEST_CASE("Combine brims merges touching brims", "[SkirtBrim]")
{
auto [gap, combine, expected_brims] = GENERATE(table<double, int, int>({
{ 5.0, 1, 1 }, // touching + combine -> one merged brim
{ 5.0, 0, 2 }, // touching, no combine -> separate
{ 60.0, 1, 2 }, // far apart -> nothing to merge
}));
DYNAMIC_SECTION("gap=" << gap << " combine_brims=" << combine) {
Print print;
Model model;
place_two_cubes_apart(gap, {
{ "skirt_loops", 1 },
{ "skirt_height", 1 },
{ "skirt_distance", 3 },
{ "skirt_type", "perobject" },
{ "print_sequence", "by layer" },
{ "brim_type", "outer_only" },
{ "brim_width", 5 },
{ "combine_brims", combine },
{ "layer_height", 0.2 },
}, print, model);
print.process();
CHECK(brim_count(print) == expected_brims);
}
}
TEST_CASE("Object brims are generated per instance", "[SkirtBrim]")
{
Print print;
Model model;
place_two_cube_instances_apart(60, {
{ "skirt_loops", 0 },
{ "brim_type", "outer_only" },
{ "brim_width", 5 },
{ "combine_brims", 0 },
}, print, model);
print.process();
REQUIRE(print.skirt_brim_groups().size() == 1);
REQUIRE(print.skirt_brim_groups().front().brims.size() == 2);
for (const Print::SkirtBrimGroup::Brim &brim : print.skirt_brim_groups().front().brims) {
REQUIRE(brim.instances.size() == 1);
REQUIRE(brim.instances.front().object_id == print.get_object(0)->id());
}
}
TEST_CASE("Uncombined neighboring brims precede their respective objects", "[SkirtBrim]")
{
Print print;
Model model;
place_two_cubes_apart(0, {
{ "skirt_loops", 0 },
{ "brim_type", "outer_only" },
{ "brim_width", 5 },
{ "combine_brims", 0 },
}, print, model);
print.process();
REQUIRE(print.skirt_brim_groups().size() == 1);
REQUIRE(print.skirt_brim_groups().front().brims.size() == 2);
CHECK(role_sequence(gcode(print), { "brim", "perimeter" }) ==
std::vector<std::string>{ "brim", "perimeter", "brim", "perimeter" });
}
TEST_CASE("Combine brims merges neighboring object instances", "[SkirtBrim]")
{
Print print;
Model model;
place_two_cube_instances_apart(5, {
{ "skirt_loops", 0 },
{ "brim_type", "outer_only" },
{ "brim_width", 5 },
{ "combine_brims", 1 },
}, print, model);
print.process();
REQUIRE(print.skirt_brim_groups().size() == 1);
REQUIRE(print.skirt_brim_groups().front().brims.size() == 1);
REQUIRE(print.skirt_brim_groups().front().brims.front().instances.size() == 2);
const std::vector<std::string> expected{ "brim", "perimeter" };
CHECK(role_sequence(gcode(print), { "brim", "perimeter" }) == expected);
}
// Each object's skirt and brim come right before that object, not all skirts then all brims first.
TEST_CASE("By-layer per-object skirt and brim precede each object", "[SkirtBrim]")
{
const std::string gcode = slice_two_cubes_apart(60, { // far apart: a skirt+brim per object
{ "skirt_loops", 1 },
{ "skirt_height", 1 },
{ "skirt_distance", 3 },
{ "skirt_type", "perobject" },
{ "print_sequence", "by layer" },
{ "brim_type", "outer_only" },
{ "brim_width", 5 },
{ "layer_height", 0.2 },
});
const std::vector<std::string> expected{ "skirt", "brim", "perimeter", "skirt", "brim", "perimeter" };
CHECK(role_sequence(gcode, { "skirt", "brim", "perimeter" }) == expected);
}
// A square's corners are 90 degrees, so they get ears only when brim_ears_max_angle is above 90.
TEST_CASE("Brim ears appear only at corners within the max angle", "[SkirtBrim]")
{
auto [max_angle, expect_ears] = GENERATE(table<int, bool>({ { 91, true }, { 90, false }, { 89, false } }));
DYNAMIC_SECTION("brim_ears_max_angle=" << max_angle) {
Print print;
init_and_process_print({ cube(20) }, print, {
{ "skirt_loops", 0 },
{ "brim_type", "brim_ears" },
{ "brim_width", 1 },
{ "brim_ears_max_angle", max_angle },
{ "initial_layer_line_width", 0.5 },
});
if (expect_ears) CHECK(brim_loop_count(print) > 0);
else CHECK(brim_loop_count(print) == 0);
}
}
SCENARIO("Skirt has the configured number of loops", "[SkirtBrim]") {
GIVEN("20mm cube and default config") {
WHEN("skirt_loops is set to 2") {
Print print;
init_and_process_print({cube(20)}, print, {
{ "skirt_height", 1 },
{ "skirt_distance", 1 },
{ "skirt_loops", 2 }
});
THEN("Skirt Extrusion collection has 2 loops in it") {
REQUIRE(print.skirt().items_count() == 2);
REQUIRE(print.skirt().flatten().entities.size() == 2);
}
}
}
}
SCENARIO("Brim has the configured number of loops", "[SkirtBrim]") {
GIVEN("20mm cube and default config, 1mm first layer width") {
WHEN("Brim is set to 6mm") {
Print print;
init_and_process_print({cube(20)}, print, {
{ "brim_type", "outer_only" },
{ "initial_layer_line_width", 1 },
{ "brim_width", 6 }
});
THEN("Brim Extrusion collection has 6 loops in it") {
REQUIRE(brim_loop_count(print) == 6);
}
}
WHEN("Brim is set to 6mm, extrusion width 0.5mm") {
Print print;
init_and_process_print({cube(20)}, print, {
{ "brim_type", "outer_only" },
{ "brim_width", 6 },
{ "initial_layer_line_width", 0.5 }
});
THEN("Brim Extrusion collection has 12 loops in it") {
REQUIRE(brim_loop_count(print) == 12);
}
}
}
}
static double first_extrusion_feedrate_for_feature(const std::string &gcode, const std::string_view feature)
{
double feedrate = 0.0;
bool feature_active = false;
GCodeReader parser;
parser.parse_buffer(gcode, [&feedrate, &feature_active, feature] (GCodeReader &self, const GCodeReader::GCodeLine &line) {
const std::string_view comment = line.comment();
if (comment.find("FEATURE:") != std::string_view::npos || comment.find("TYPE:") != std::string_view::npos)
feature_active = comment.find(feature) != std::string_view::npos;
if (feature_active && line.extruding(self) && line.dist_XY(self) > 0) {
feedrate = line.new_F(self);
self.quit_parsing();
}
});
return feedrate;
}
TEST_CASE("Skirt height is honored", "[SkirtBrim]") {
DynamicPrintConfig config = DynamicPrintConfig::full_print_config();
config.set_deserialize_strict({
{ "skirt_loops", 1 },
{ "skirt_height", 5 },
{ "wall_loops", 0 },
});
std::string gcode;
SECTION("printing a single object") {
gcode = slice({ cube(20) }, config);
}
SECTION("printing multiple objects") {
gcode = slice({ cube(20), cube(20) }, config);
}
REQUIRE(layers_with_role(gcode, "skirt").size() == (size_t) config.opt_int("skirt_height"));
}
TEST_CASE("Brim uses first layer speed", "[SkirtBrim]") {
DynamicPrintConfig config = Slic3r::DynamicPrintConfig::full_print_config();
config.set_deserialize_strict({
{ "brim_type", "outer_only" },
{ "brim_width", 5 },
{ "gcode_comments", true },
{ "initial_layer_speed", 10 },
{ "initial_layer_infill_speed", 20 },
{ "machine_start_gcode", "" },
{ "skirt_loops", 0 },
{ "slow_down_for_layer_cooling", false },
{ "z_hop", 0 }
});
const std::string gcode = Slic3r::Test::slice({cube(20)}, config);
const double brim_feedrate = first_extrusion_feedrate_for_feature(gcode, "Brim");
REQUIRE(brim_feedrate > 0.0);
REQUIRE_THAT(brim_feedrate, Catch::Matchers::WithinAbs(600.0, 1e-3));
const double bottom_surface_feedrate = first_extrusion_feedrate_for_feature(gcode, "Bottom surface");
REQUIRE(bottom_surface_feedrate > 0.0);
REQUIRE_THAT(bottom_surface_feedrate, Catch::Matchers::WithinAbs(1200.0, 1e-3));
}
SCENARIO("Skirt and brim generation", "[SkirtBrim]") {
GIVEN("A default configuration") {
DynamicPrintConfig config = DynamicPrintConfig::full_print_config();
config.set_num_extruders(4);
config.set_deserialize_strict({
{ "initial_layer_print_height", 0.3 },
// avoid altering speeds unexpectedly
{ "slow_down_for_layer_cooling", false },
{ "initial_layer_speed", "100%" },
// remove noise from top/solid layers
{ "top_shell_layers", 0 },
{ "bottom_shell_layers", 1 },
{ "machine_start_gcode", "T[initial_tool]\n" },
});
WHEN("Brim width is set to 5") {
config.set_deserialize_strict({
{ "wall_loops", 0 },
{ "skirt_loops", 0 },
{ "brim_type", "outer_only" },
{ "brim_width", 5 },
});
THEN("Brim is generated") {
std::string gcode = slice({ cube(20) }, config);
REQUIRE(! layers_with_role(gcode, "brim").empty());
}
}
WHEN("brim width to 1 with layer_width of 0.5") {
config.set_deserialize_strict({
{ "skirt_loops", 0 },
{ "initial_layer_line_width", 0.5 },
{ "brim_type", "outer_only" },
{ "brim_width", 1 },
});
THEN("2 brim lines") {
Print print;
init_and_process_print({ cube(20) }, print, config);
REQUIRE(brim_loop_count(print) == 2);
}
}
WHEN("Object is plated with overhang support and a brim") {
config.set_deserialize_strict({
{ "layer_height", 0.4 },
{ "initial_layer_print_height", 0.4 },
{ "skirt_loops", 1 },
{ "skirt_distance", 0 },
{ "enable_support", 1 },
{ "brim_type", "outer_only" },
{ "brim_width", 5 },
});
THEN("Support and brim are both emitted") {
std::string gcode = slice({ TestMesh::overhang }, config);
REQUIRE(! layers_with_role(gcode, "support").empty());
REQUIRE(! layers_with_role(gcode, "brim").empty());
}
}
WHEN("an object with support is surrounded by a skirt") {
config.set_deserialize_strict({
{ "enable_support", 1 },
{ "skirt_loops", 1 },
{ "skirt_distance", 2 },
{ "brim_type", "no_brim" },
{ "z_hop", 0 },
});
THEN("the skirt is long enough to enclose the object and its support") {
std::string gcode = slice({ TestMesh::overhang }, config);
const double first_layer_z = config.opt_float("initial_layer_print_height");
// On the first layer, accumulate the skirt loop length and collect the
// object + support extrusion points; the skirt must enclose them.
double skirt_length = 0.0;
Points footprint;
GCodeReader parser;
parser.parse_buffer(gcode, [&](GCodeReader &self, const GCodeReader::GCodeLine &line) {
if (! line.extruding(self) || line.dist_XY(self) <= 0 || std::abs(self.z() - first_layer_z) > 0.01)
return;
if (line.comment().find("skirt") != std::string_view::npos)
skirt_length += line.dist_XY(self);
else
footprint.push_back(Point::new_scale(line.new_X(self), line.new_Y(self)));
});
const double hull_perimeter = unscale<double>(Geometry::convex_hull(footprint).split_at_first_point().length());
REQUIRE(hull_perimeter > 0.0); // guard against an empty footprint passing trivially
REQUIRE(skirt_length > hull_perimeter);
}
}
WHEN("Large minimum skirt length is used.") {
// One skirt loop around a 20mm cube is ~88mm, so 500mm forces extra loops.
config.set_deserialize_strict({
{ "skirt_loops", 1 },
{ "min_skirt_length", 500 },
});
THEN("The skirt is extended to at least the minimum length") {
std::string gcode = slice({ cube(20) }, config);
double skirt_length = 0.0;
GCodeReader parser;
parser.parse_buffer(gcode, [&skirt_length](GCodeReader &self, const GCodeReader::GCodeLine &line) {
if (line.extruding(self) && line.comment().find("skirt") != std::string_view::npos)
skirt_length += line.dist_XY(self);
});
REQUIRE(skirt_length >= 500.0);
}
}
}
}
// Belt printers ---------------------------------------------------------------
//
// On a tilted belt the brim is laid onto the belt PLANE rather than into the Z=0
// bed plane, so it is spread across many layers instead of living on the first
// one. The discriminating measurement is the number of contiguous brim runs in
// the G-code: a flat plate brim gives a single run, a belt brim gives one per
// layer that carries a band. Distinct Z values are useless here, because the
// machine-frame transform couples Y into Z so every belt move has its own Z.
static DynamicPrintConfig belt_brim_config()
{
DynamicPrintConfig config = DynamicPrintConfig::full_print_config();
config.set_deserialize_strict({
{ "belt_printer", 1 },
{ "belt_slice_rotation", "x" },
{ "belt_slice_rotation_angle", 45 },
{ "belt_slice_rotation_global", 1 },
{ "gcode_remap_x", "rev_x" },
{ "gcode_remap_y", "pos_z" },
{ "gcode_remap_z", "pos_y" },
{ "layer_height", 0.2 },
{ "initial_layer_print_height", 0.2 },
{ "skirt_loops", 0 },
{ "top_shell_layers", 0 },
{ "bottom_shell_layers", 1 },
{ "machine_start_gcode", "T[initial_tool]\n" },
});
return config;
}
// Same belt as belt_brim_config(), but with `filaments` distinct filaments so the brim's
// tool selection can be observed. Kept separate from belt_brim_config() so the existing
// single-filament belt tests are untouched.
static DynamicPrintConfig belt_brim_multifilament_config(unsigned int filaments,
std::initializer_list<Slic3r::ConfigBase::SetDeserializeItem> extra = {})
{
DynamicPrintConfig config = multifilament_config(filaments);
config.set_deserialize_strict({
{ "belt_printer", 1 },
{ "belt_slice_rotation", "x" },
{ "belt_slice_rotation_angle", 45 },
{ "belt_slice_rotation_global", 1 },
{ "gcode_remap_x", "rev_x" },
{ "gcode_remap_y", "pos_z" },
{ "gcode_remap_z", "pos_y" },
{ "layer_height", 0.2 },
{ "initial_layer_print_height", 0.2 },
{ "skirt_loops", 0 },
{ "top_shell_layers", 0 },
{ "bottom_shell_layers", 1 },
{ "machine_start_gcode", "T[initial_tool]\n" },
});
if (extra.size() > 0)
config.set_deserialize_strict(extra);
return config;
}
// 0-based tool indices used by extrusions whose role comment contains `role` (needs
// gcode_comments). Mirrors tools_for_role in test_multifilament.cpp; statics do not cross
// translation units, so it is repeated here.
static std::set<int> belt_tools_for_role(const std::string &gcode, const std::string &role)
{
std::set<int> tools;
int current_tool = 0;
GCodeReader reader;
reader.parse_buffer(gcode, [&](GCodeReader &self, const GCodeReader::GCodeLine &line) {
const std::string cmd(line.cmd());
if (cmd.size() >= 2 && cmd[0] == 'T' && std::isdigit((unsigned char) cmd[1]))
current_tool = std::stoi(cmd.substr(1));
else if (line.extruding(self) && std::string(line.comment()).find(role) != std::string::npos)
tools.insert(current_tool);
});
return tools;
}
// Machine Z of the first extruding move whose role comment contains `role`, in file order;
// numeric_limits<double>::max() when the role never extrudes.
static double first_role_z(const std::string &gcode, const std::string &role)
{
double z = std::numeric_limits<double>::max();
GCodeReader parser;
parser.parse_buffer(gcode, [&z, &role](GCodeReader &self, const GCodeReader::GCodeLine &line) {
if (line.extruding(self) && line.comment().find(role) != std::string_view::npos) {
z = self.z();
self.quit_parsing();
}
});
return z;
}
// Number of object layers that carry a belt brim band. Each such band is emitted as one
// contiguous brim pass, so for a single object whose first-contact layer carries a band
// (the apron prologue folds into that layer's pass) this equals role_passes(gcode, "brim").
static int nonempty_belt_brim_layers(const PrintObject &object)
{
int n = 0;
for (const ExtrusionEntityCollection &band : object.belt_brim_by_layer())
if (! band.empty())
++ n;
return n;
}
// For each active tool, the ordinal (1-based, over extruding moves) of the FIRST move whose
// role comment contains `role`. Lets a per-object ordering check key off the object's
// unique wall filament.
static std::map<int, long> first_move_by_tool(const std::string &gcode, const std::string &role)
{
std::map<int, long> first;
int tool = 0;
long idx = 0;
GCodeReader reader;
reader.parse_buffer(gcode, [&](GCodeReader &self, const GCodeReader::GCodeLine &line) {
const std::string cmd(line.cmd());
if (cmd.size() >= 2 && cmd[0] == 'T' && std::isdigit((unsigned char) cmd[1])) {
tool = std::stoi(cmd.substr(1));
return;
}
if (! line.extruding(self))
return;
++ idx;
if (std::string(line.comment()).find(role) != std::string::npos && ! first.count(tool))
first[tool] = idx;
});
return first;
}
// C - the band coincident with the object's FIRST contact with the belt must not be dropped:
// a belt brim has to appear at or below the object's first perimeter. On the unfixed feature
// the first-contact band is dropped and the first brim then appears only at a later (higher)
// layer. Machine Z is meaningful and shared between roles under the belt remap, so the first
// brim's Z must not exceed the first perimeter's. Both with and without support.
TEST_CASE("Belt brim is laid at the object's first belt contact", "[SkirtBrim][belt]")
{
const bool support = GENERATE(false, true);
DYNAMIC_SECTION("enable_support=" << support) {
DynamicPrintConfig config = belt_brim_config();
config.set_deserialize_strict({
{ "brim_type", "outer_only" },
{ "brim_width", 4 },
{ "leading_brim_length", 0 },
{ "extra_brim_width", 0 },
{ "brim_object_gap", 0 },
{ "enable_support", support ? 1 : 0 },
});
const std::string gcode = slice({ cube(20) }, config);
const double brim_z = first_role_z(gcode, "brim");
const double peri_z = first_role_z(gcode, "perimeter");
REQUIRE(brim_z < std::numeric_limits<double>::max());
REQUIRE(peri_z < std::numeric_limits<double>::max());
CHECK(brim_z <= peri_z + EPSILON);
}
}
// C control - when the band's own object layer has extrusion (any interior layer of a solid
// cube), the band takes the ordinary process_layer() path and must be drawn immediately
// before that layer's perimeters, and exactly once: never dropped, never double-emitted.
TEST_CASE("Belt brim on an object layer precedes its perimeters, once", "[SkirtBrim][belt]")
{
DynamicPrintConfig config = belt_brim_config();
config.set_deserialize_strict({
{ "brim_type", "outer_only" },
{ "brim_width", 4 },
{ "brim_object_gap", 0 },
});
Print print;
Model model;
init_print({ cube(20) }, print, model, config);
const std::string gc = gcode(print);
// Ordering: the first thing extruded is brim, then perimeter.
const std::vector<std::string> seq = role_sequence(gc, { "brim", "perimeter" });
REQUIRE(seq.size() >= 2);
CHECK(seq[0] == "brim");
CHECK(seq[1] == "perimeter");
// Exactly once: every band is one contiguous pass (the apron prologue folds into the
// first layer's), so the pass count equals the number of layers carrying a band - not
// twice it, which double-emission would give, nor fewer, which a dropped band would.
const int bands = nonempty_belt_brim_layers(*print.objects().front());
REQUIRE(bands > 0);
CHECK(role_passes(gc, "brim") == bands);
}
// B - single extruder (filament id 1). Every band must survive the 1-based -> 0-based
// filament-id conversion the apron path performs: a wrong conversion drops all single-extruder
// bands, so the pass count would collapse. The expected count is derived from the sliced
// layers, not a ratio.
TEST_CASE("Belt brim on a single extruder emits every band once", "[SkirtBrim][belt]")
{
DynamicPrintConfig config = belt_brim_config();
config.set_deserialize_strict({
{ "brim_type", "outer_only" },
{ "brim_width", 4 },
{ "brim_object_gap", 0 },
});
Print print;
Model model;
init_print({ cube(20) }, print, model, config);
const std::string gc = gcode(print);
const int expected = nonempty_belt_brim_layers(*print.objects().front());
REQUIRE(expected > 0);
CHECK(role_passes(gc, "brim") == expected);
CHECK(belt_tools_for_role(gc, "brim") == std::set<int>{ 0 }); // filament 1 -> tool 0
}
// B - multi extruder (wall filament id 2). Every belt-brim line must print on the object's
// wall filament (index 2 -> tool 1), and the total number of passes must equal the
// single-extruder baseline: no per-filament doubling.
TEST_CASE("Belt brim on a multi-extruder object uses the wall filament, no doubling", "[SkirtBrim][belt]")
{
// Single-extruder baseline built the same way (same nozzle/flow), so the band geometry -
// and thus the band count - is identical and only the filament assignment differs.
DynamicPrintConfig base = belt_brim_multifilament_config(1, {
{ "brim_type", "outer_only" },
{ "brim_width", 4 },
{ "brim_object_gap", 0 },
});
const int baseline = role_passes(slice({ cube(20) }, base), "brim");
REQUIRE(baseline > 0);
DynamicPrintConfig config = belt_brim_multifilament_config(2, {
{ "brim_type", "outer_only" },
{ "brim_width", 4 },
{ "brim_object_gap", 0 },
{ "outer_wall_filament_id", 2 },
{ "inner_wall_filament_id", 2 },
});
const std::string gc = slice({ cube(20) }, config);
CHECK(belt_tools_for_role(gc, "brim") == std::set<int>{ 1 }); // filament 2 -> tool 1
CHECK(role_passes(gc, "brim") == baseline);
}
// B - two objects offset ALONG the belt (Y, since the tilt is about X), each with its own
// wall filament. Each object's brim/apron must print on that object's filament AND before
// that object's own perimeters. The object is identified by its unique tool.
TEST_CASE("Belt brim of each object precedes its perimeters on its own filament", "[SkirtBrim][belt]")
{
DynamicPrintConfig config = belt_brim_multifilament_config(2, {
{ "brim_type", "outer_only" },
{ "brim_width", 4 },
{ "leading_brim_length", 6 },
{ "brim_object_gap", 0 },
});
std::vector<TriangleMesh> meshes;
meshes.emplace_back(cube(20));
TriangleMesh second = cube(20);
second.translate(0.f, 40.f, 0.f); // offset along the belt so it lands well after the first
meshes.emplace_back(std::move(second));
const std::vector<std::vector<Slic3r::ConfigBase::SetDeserializeItem>> overrides {
{ { "outer_wall_filament_id", 1 }, { "inner_wall_filament_id", 1 } },
{ { "outer_wall_filament_id", 2 }, { "inner_wall_filament_id", 2 } },
};
Print print;
Model model;
init_print(std::move(meshes), print, model, config, &overrides, /*arrange=*/false);
print.process();
const std::string gc = gcode(print);
// Both brims appear, each on its object's wall filament (1 -> T0, 2 -> T1).
CHECK(belt_tools_for_role(gc, "brim") == std::set<int>{ 0, 1 });
const std::map<int, long> brim_first = first_move_by_tool(gc, "brim");
const std::map<int, long> peri_first = first_move_by_tool(gc, "perimeter");
for (int tool : { 0, 1 }) {
REQUIRE(brim_first.count(tool) == 1);
REQUIRE(peri_first.count(tool) == 1);
CHECK(brim_first.at(tool) < peri_first.at(tool));
}
}
// D - the belt-brim predicate must not fire on a request that produces no belt brim.
// leading_brim_length / extra_brim_width only feed the OUTER ring, so inner_only with zero
// brim_width yields nothing and must not claim the layers the prime tower / spiral vase need.
TEST_CASE("Belt inner-only leading brim does not reject the prime tower or spiral vase", "[SkirtBrim][belt]")
{
auto inner_leading = [](std::initializer_list<Slic3r::ConfigBase::SetDeserializeItem> extra) {
DynamicPrintConfig config = belt_brim_config();
config.set_deserialize_strict({
{ "brim_type", "inner_only" },
{ "brim_width", 0 },
{ "leading_brim_length", 6 },
{ "brim_object_gap", 0 },
});
config.set_deserialize_strict(extra);
return config;
};
SECTION("prime tower is left alone") {
Print print;
Model model;
init_print({ cube(20) }, print, model, inner_leading({ { "enable_prime_tower", 1 } }));
CHECK_FALSE(print.objects().front()->has_belt_brim());
CHECK(print.validate().string.empty());
}
SECTION("spiral vase is left alone") {
Print print;
Model model;
init_print({ cube(20) }, print, model, inner_leading({ { "spiral_mode", 1 } }));
CHECK_FALSE(print.objects().front()->has_belt_brim());
CHECK(print.validate().string.empty());
}
SECTION("a real inner brim still rejects the prime tower") {
DynamicPrintConfig config = belt_brim_config();
config.set_deserialize_strict({
{ "brim_type", "inner_only" },
{ "brim_width", 4 },
{ "brim_object_gap", 0 },
{ "enable_prime_tower", 1 },
});
Print print;
Model model;
init_print({ cube(20) }, print, model, config);
CHECK(print.objects().front()->has_belt_brim());
CHECK_FALSE(print.validate().string.empty());
}
}
TEST_CASE("Belt brim spans many layers instead of one", "[SkirtBrim][belt]")
{
DynamicPrintConfig config = belt_brim_config();
config.set_deserialize_strict({
{ "brim_type", "outer_only" },
{ "brim_width", 5 },
});
const std::string gcode = slice({ cube(20) }, config);
// A plate-brim implementation would score 1 here.
CHECK(role_passes(gcode, "brim") > 10);
}
TEST_CASE("Belt brim is absent when both widths are zero", "[SkirtBrim][belt]")
{
// The "no effect when disabled" guard: brim_type Auto is the shipped default and
// reports has_brim() even at width 0, so this also pins the gate that keeps the
// flat plate brim from running on a tilted belt.
const char *brim_type = GENERATE("auto_brim", "outer_only", "no_brim");
DYNAMIC_SECTION("brim_type " << brim_type) {
DynamicPrintConfig config = belt_brim_config();
config.set_deserialize_strict({
{ "brim_type", brim_type },
{ "brim_width", 0 },
{ "leading_brim_length", 0 },
{ "extra_brim_width", 0 },
});
const std::string gcode = slice({ cube(20) }, config);
CHECK(role_passes(gcode, "brim") == 0);
}
}
TEST_CASE("Leading brim length alone produces a belt brim", "[SkirtBrim][belt]")
{
// Exercises the leading_brim_length-only enablement path and the downhill sweep.
DynamicPrintConfig config = belt_brim_config();
config.set_deserialize_strict({
{ "brim_type", "outer_only" },
{ "brim_width", 0 },
{ "leading_brim_length", 5 },
{ "brim_object_gap", 0 },
});
const std::string gcode = slice({ cube(20) }, config);
CHECK(role_passes(gcode, "brim") > 0);
}
TEST_CASE("Leading brim length reaches further ahead of the object", "[SkirtBrim][belt]")
{
// Compared between two runs rather than against an absolute coordinate, so the
// assertion survives any change of origin or axis remap.
auto brim_extent = [](double extra) {
DynamicPrintConfig config = belt_brim_config();
config.set_deserialize_strict({
{ "brim_type", "outer_only" },
{ "brim_width", 3 },
{ "leading_brim_length", extra },
{ "brim_object_gap", 0 },
});
const std::string gcode = slice({ cube(20) }, config);
// The apron prints before the object reaches the belt, so it shows up as brim
// extrusion at the lowest machine Z of any brim move.
double min_z = std::numeric_limits<double>::max();
GCodeReader parser;
parser.parse_buffer(gcode, [&min_z](GCodeReader &self, const GCodeReader::GCodeLine &line) {
if (line.extruding(self) && line.comment().find("brim") != std::string_view::npos)
min_z = std::min(min_z, static_cast<double>(self.z()));
});
return min_z;
};
const double without = brim_extent(0.);
const double with = brim_extent(10.);
REQUIRE(without < std::numeric_limits<double>::max());
REQUIRE(with < std::numeric_limits<double>::max());
CHECK(with < without);
}
TEST_CASE("Every brim type slices on a belt printer", "[SkirtBrim][belt]")
{
// Auto / Mouse ear / Painted collapse to outer-only rather than crashing or
// silently producing nothing.
const char *brim_type = GENERATE("auto_brim", "brim_ears", "painted", "outer_only",
"inner_only", "outer_and_inner", "no_brim");
DYNAMIC_SECTION("brim_type " << brim_type) {
DynamicPrintConfig config = belt_brim_config();
config.set_deserialize_strict({
{ "brim_type", brim_type },
{ "brim_width", 5 },
});
const std::string gcode = slice({ cube(20) }, config);
REQUIRE(! gcode.empty());
if (std::string(brim_type) == "no_brim")
CHECK(role_passes(gcode, "brim") == 0);
else if (std::string(brim_type) != "inner_only")
// A solid cube has no holes, so inner_only legitimately yields nothing.
CHECK(role_passes(gcode, "brim") > 0);
}
}
TEST_CASE("An untilted belt printer gets no brim", "[SkirtBrim][belt]")
{
// Belt brim needs a tilt to have a belt plane to lie on, and the flat plate brim
// cannot reach the G-code on any belt printer: it is emitted out of
// skirt_brim_groups(), which _make_skirt() builds, and that returns early for every
// belt printer. So an untilted belt printer gets nothing - unchanged by this
// feature. Making the flat brim work here would mean reopening the belt skirt gate,
// which is a separate change; Print::validate() warns instead.
DynamicPrintConfig config = belt_brim_config();
config.set_deserialize_strict({
{ "belt_slice_rotation", "none" },
{ "brim_type", "outer_only" },
{ "brim_width", 5 },
});
const std::string gcode = slice({ cube(20) }, config);
CHECK(role_passes(gcode, "brim") == 0);
}
TEST_CASE("Belt brim does not resurrect the skirt", "[SkirtBrim][belt]")
{
DynamicPrintConfig config = belt_brim_config();
config.set_deserialize_strict({
{ "brim_type", "outer_only" },
{ "brim_width", 5 },
{ "skirt_loops", 2 },
});
const std::string gcode = slice({ cube(20) }, config);
CHECK(role_passes(gcode, "skirt") == 0);
}
TEST_CASE("Belt brim lines all have the same width", "[SkirtBrim][belt]")
{
// Each brim line's extrusion volume comes from its nozzle-to-belt clearance. Anchoring
// every line to a fixed fraction of its own band gives them all the same clearance, so
// they all come out the same width. The nominal-spacing lattice this replaced let each
// line land wherever it fell inside its band, so the clearance - and the width with it -
// varied by 2x, which showed up as visibly ragged brim.
DynamicPrintConfig config = belt_brim_config();
config.set_deserialize_strict({
{ "brim_type", "outer_only" },
{ "brim_width", 5 },
{ "brim_object_gap", 0 },
});
Print print;
init_and_process_print({ cube(20) }, print, config);
const PrintObject *obj = print.objects().front();
std::vector<float> widths;
auto collect = [&widths](const ExtrusionEntityCollection &coll) {
for (const ExtrusionEntity *ee : coll.entities)
if (const auto *path = dynamic_cast<const ExtrusionPath *>(ee))
widths.push_back(path->width);
};
for (const ExtrusionEntityCollection &band : obj->belt_brim_by_layer())
collect(band);
for (const BeltBrimBand &band : obj->belt_brim_prologue())
collect(band.fills);
REQUIRE(widths.size() > 10);
const float lo = *std::min_element(widths.begin(), widths.end());
const float hi = *std::max_element(widths.begin(), widths.end());
CHECK_THAT(hi, Catch::Matchers::WithinRel(lo, 1e-4));
}
TEST_CASE("Belt apron survives another object printing at the same Z", "[SkirtBrim][belt]")
{
// An apron band prints below its OWN object's first layer, but with two objects on the
// belt the second one is already printing at that print_z. The layer then has an
// object layer and takes the ordinary process_layer() path rather than the brim-only
// branch, so the band must be emitted from both or it is silently dropped. A
// single-object print cannot exercise this.
auto brim_passes = [](int object_count) {
DynamicPrintConfig config = belt_brim_config();
config.set_deserialize_strict({
{ "brim_type", "outer_only" },
{ "brim_width", 3 },
{ "leading_brim_length", 8 },
{ "brim_object_gap", 0 },
});
std::vector<TriangleMesh> meshes;
for (int i = 0; i < object_count; ++ i) {
TriangleMesh m = cube(20);
// Offset along the belt so the second object starts well after the first.
m.translate(0.f, float(40 * i), 0.f);
meshes.emplace_back(std::move(m));
}
Print print;
Model model;
init_print(std::move(meshes), print, model, config);
print.process();
return role_passes(gcode(print), "brim");
};
const int one = brim_passes(1);
const int two = brim_passes(2);
REQUIRE(one > 0);
// Two identical objects should carry twice the brim. Merely asserting `two > one`
// would not be decisive: the FIRST object's apron survives the bug, because nothing
// else is printing that early, so only the second object's apron goes missing.
// Requiring close to 2x is what actually detects the dropped bands.
CHECK(two >= 1.8 * one);
}
TEST_CASE("Belt brim allows instances placed across the belt", "[SkirtBrim][belt]")
{
// Only movement ALONG the belt changes an instance's belt-floor Z, so copies placed
// side by side ACROSS it share one set of bands and must still get a brim. The first
// version of this guard refused every multi-instance object outright, silently
// dropping the brim.
//
// The global belt flags are off here so the instances stay in one PrintObject; with
// them on, PrintApply splits each instance into its own object and the case cannot
// arise at all.
auto multi_instance_has_brim = [](double dx, double dy) {
DynamicPrintConfig config = belt_brim_config();
config.set_deserialize_strict({
{ "belt_slice_rotation_global", 0 },
{ "belt_preslice_global", 0 },
{ "preslice_remap_global", 0 },
{ "brim_type", "outer_only" },
{ "brim_width", 4 },
{ "brim_object_gap", 0 },
});
Print print;
Model model;
ModelObject *object = model.add_object();
object->name += "object.stl";
object->add_volume(cube(20));
object->add_instance()->set_offset(Vec3d(80., 80., 0.));
object->add_instance()->set_offset(Vec3d(80. + dx, 80. + dy, 0.));
object->ensure_on_bed();
print.auto_assign_extruders(object);
print.apply(model, config);
print.validate();
print.set_status_silent();
print.process();
REQUIRE(print.objects().size() == 1);
REQUIRE(print.objects().front()->instances().size() == 2);
return print.objects().front()->has_belt_brim();
};
// X is across the belt when the tilt is about X, since the shear then runs along Y.
CHECK(multi_instance_has_brim(40., 0.));
// Y is along the belt: the copies sit at different belt heights and would each need
// their own bands, so the brim is refused (and validate() warns).
CHECK_FALSE(multi_instance_has_brim(0., 40.));
}
TEST_CASE("Belt brim coexists with support material", "[SkirtBrim][belt]")
{
// Supports put extra layers into the same z stream as the apron bands, which is what
// the three-way merge in collect_layers_to_print() exists to handle: a band sharing a
// print_z with a support layer of the SAME object used to overwrite it in the
// print-wide merge. A smoke test - it cannot prove the collision occurred - but it
// does exercise the merge with all three streams populated.
DynamicPrintConfig config = belt_brim_config();
config.set_deserialize_strict({
{ "brim_type", "outer_only" },
{ "brim_width", 4 },
{ "leading_brim_length", 6 },
{ "brim_object_gap", 0 },
{ "enable_support", 1 },
});
const std::string gc = slice({ TestMesh::overhang }, config);
REQUIRE(! gc.empty());
CHECK(role_passes(gc, "brim") > 0);
}