ENH: add grab length

1.During the filament change, the extruder will extrude an extra length
of grap_length for the corresponding detection, so the purge volume can
reduce this length.

jira:NEW

Signed-off-by: xun.zhang <xun.zhang@bambulab.com>
Change-Id: I14f55a3200c1dd48b1603e50280d0c29e1319ebe
(cherry picked from commit 16cadec565f987e6baae97428d5392c1f8e7ad39)

resources/profiles/BBL/machine/fdm_machine_common.json

@@ -20,6 +20,9 @@
         "0x0"
     ],
     "gcode_flavor": "marlin",
+    "grab_length" : [
+        "0"
+    ],
     "silent_mode": "0",
     "long_retractions_when_cut": [
         "0"

src/libslic3r/GCode.cpp

@@ -6480,6 +6480,8 @@ std::string GCode::set_extruder(unsigned int filament_id, double print_z, bool b
         old_retract_length = m_config.retraction_length.get_at(previous_extruder_id);
         old_retract_length_toolchange = m_config.retract_length_toolchange.get_at(previous_extruder_id);
         old_filament_temp = this->on_first_layer()? m_config.nozzle_temperature_initial_layer.get_at(previous_filament_id) : m_config.nozzle_temperature.get_at(previous_filament_id);
+        //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.
+        float grab_purge_volume = m_config.grab_length.get_at(extruder_id) * 2.4;
         if (previous_extruder_id != extruder_id) {
             //calc flush volume between the same extruder id
             int previous_filament_id_in_new_extruder = m_writer.filament(extruder_id) != nullptr ? m_writer.filament(extruder_id)->id() : -1;
@@ -6494,6 +6496,7 @@ std::string GCode::set_extruder(unsigned int filament_id, double print_z, bool b
             wipe_volume = flush_matrix[previous_filament_id * number_of_extruders + filament_id];
             wipe_volume *= m_config.flush_multiplier.get_at(extruder_id);  // if is multi_extruder only use the fist extruder matrix
         }
+        wipe_volume = std::max(0.f, wipe_volume-grab_purge_volume);
 
         old_filament_e_feedrate = (int) (60.0 * m_config.filament_max_volumetric_speed.get_at(previous_filament_id) / filament_area);
         old_filament_e_feedrate = old_filament_e_feedrate == 0 ? 100 : old_filament_e_feedrate;

src/libslic3r/Preset.cpp

@@ -909,6 +909,7 @@ static std::vector<std::string> s_Preset_printer_options {
     "printhost_cafile","printhost_port","printhost_authorization_type",
     "printhost_user", "printhost_password", "printhost_ssl_ignore_revoke", "thumbnails", "thumbnails_format",
     "use_firmware_retraction", "use_relative_e_distances", "printer_notes",
+    "grab_length",
     "cooling_tube_retraction",
     "cooling_tube_length", "high_current_on_filament_swap", "parking_pos_retraction", "extra_loading_move", "purge_in_prime_tower", "enable_filament_ramming",
     "z_offset",

src/libslic3r/Print.cpp

@@ -206,7 +206,8 @@ bool Print::invalidate_state_by_config_options(const ConfigOptionResolver & /* n
         "long_retractions_when_cut",
         "retraction_distances_when_cut",
         "filament_long_retractions_when_cut",
-        "filament_retraction_distances_when_cut"
+        "filament_retraction_distances_when_cut",
+        "grab_length"
     };
 
     static std::unordered_set<std::string> steps_ignore;
@@ -2762,7 +2763,6 @@ void Print::_make_wipe_tower()
         // Get wiping matrix to get number of extruders and convert vector<double> to vector<float>:
         bool               is_mutli_extruder = m_config.nozzle_diameter.values.size() > 1;
         size_t nozzle_nums = m_config.nozzle_diameter.values.size();
-        if (is_mutli_extruder) {
         using FlushMatrix = std::vector<std::vector<float>>;
         std::vector<FlushMatrix> multi_extruder_flush;
         for (size_t nozzle_id = 0; nozzle_id < nozzle_nums; ++nozzle_id) {
@@ -2801,6 +2801,10 @@ void Print::_make_wipe_tower()
                         layer_tools.wiping_extrusions().mark_wiping_extrusions(*this, current_filament_id, filament_id, volume_to_purge);
                 }
 
+                //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.
+                float grab_purge_volume = m_config.grab_length.get_at(nozzle_id) * 2.4; //(diameter/2)^2*PI=2.4
+                volume_to_purge = std::max(0.f, volume_to_purge - grab_purge_volume);
+
                 wipe_tower.plan_toolchange((float)layer_tools.print_z, (float)layer_tools.wipe_tower_layer_height, current_filament_id, filament_id,
                     m_config.prime_volume, volume_to_purge);
                 current_filament_id = filament_id;
@@ -2818,57 +2822,6 @@ void Print::_make_wipe_tower()
                 break;
         }
         }
-        else {
-            std::vector<float> flush_matrix(cast<float>(get_flush_volumes_matrix(m_config.flush_volumes_matrix.values, 0, nozzle_nums)));
-
-            // Extract purging volumes for each extruder pair:
-            std::vector<std::vector<float>> wipe_volumes;
-            for (unsigned int i = 0; i < number_of_extruders; ++i)
-                wipe_volumes.push_back(std::vector<float>(flush_matrix.begin() + i * number_of_extruders, flush_matrix.begin() + (i + 1) * number_of_extruders));
-
-
-            // BBS: priming logic is removed, so get the initial extruder by first_extruder()
-            unsigned int current_extruder_id = m_wipe_tower_data.tool_ordering.first_extruder();
-            for (auto &layer_tools : m_wipe_tower_data.tool_ordering.layer_tools()) { // for all layers
-                if (!layer_tools.has_wipe_tower) continue;
-                bool first_layer = &layer_tools == &m_wipe_tower_data.tool_ordering.front();
-                wipe_tower.plan_toolchange((float)layer_tools.print_z, (float)layer_tools.wipe_tower_layer_height, current_extruder_id, current_extruder_id);
-
-                for (const auto extruder_id : layer_tools.extruders) {
-                    // BBS: priming logic is removed, so no need to do toolchange for first extruder
-                    if (/*(first_layer && extruder_id == m_wipe_tower_data.tool_ordering.all_extruders().back()) || */extruder_id != current_extruder_id) {
-                        float volume_to_purge = wipe_volumes[current_extruder_id][extruder_id];
-                        volume_to_purge *= m_config.flush_multiplier.get_at(0);
-
-                        // Not all of that can be used for infill purging:
-                        //volume_to_purge -= (float)m_config.filament_minimal_purge_on_wipe_tower.get_at(extruder_id);
-
-                        // try to assign some infills/objects for the wiping:
-                        volume_to_purge = layer_tools.wiping_extrusions().mark_wiping_extrusions(*this, current_extruder_id, extruder_id, volume_to_purge);
-
-                        // add back the minimal amount toforce on the wipe tower:
-                        //volume_to_purge += (float)m_config.filament_minimal_purge_on_wipe_tower.get_at(extruder_id);
-
-                        // request a toolchange at the wipe tower with at least volume_to_wipe purging amount
-                        wipe_tower.plan_toolchange((float)layer_tools.print_z, (float)layer_tools.wipe_tower_layer_height,
-                                                   current_extruder_id, extruder_id, m_config.prime_volume, volume_to_purge);
-                        current_extruder_id = extruder_id;
-                    }
-                }
-                layer_tools.wiping_extrusions().ensure_perimeters_infills_order(*this);
-
-                // if enable timelapse, slice all layer
-                if (enable_timelapse_print()) {
-                    if (layer_tools.wipe_tower_partitions == 0)
-                        wipe_tower.set_last_layer_extruder_fill(false);
-                    continue;
-                }
-
-                if (&layer_tools == &m_wipe_tower_data.tool_ordering.back() || (&layer_tools + 1)->wipe_tower_partitions == 0)
-                    break;
-            }
-            }
-        }
 
         // Generate the wipe tower layers.
         m_wipe_tower_data.tool_changes.reserve(m_wipe_tower_data.tool_ordering.layer_tools().size());

src/libslic3r/PrintConfig.cpp

@@ -1922,6 +1922,13 @@ void PrintConfigDef::init_fff_params()
     def->mode    = comAdvanced;
     def->set_default_value(new ConfigOptionFloat(0));
 
+    def = this->add("grab_length",coFloats);
+    def->label = L("Grab length");
+    def->sidetext = L("mm");
+    def->min = 0;
+    def->mode = comDevelop;
+    def->set_default_value(new ConfigOptionFloats({0}));
+
     def = this->add("extruder_colour", coStrings);
     def->label = L("Extruder Color");
     def->tooltip = L("Only used as a visual help on UI.");

src/libslic3r/PrintConfig.hpp

@@ -1455,6 +1455,7 @@ PRINT_CONFIG_CLASS_DERIVED_DEFINE(
     ((ConfigOptionPercents,            filament_shrinkage_compensation_z))
     ((ConfigOptionBool,                gcode_label_objects))
     ((ConfigOptionBool,                exclude_object))
+    ((ConfigOptionFloats,             grab_length))
     ((ConfigOptionBool,                gcode_comments))
     ((ConfigOptionInt,                 slow_down_layers))
     ((ConfigOptionInts,                support_material_interface_fan_speed))