Introduced parameter smoothing segment length

This parameter influences the number of division a line will undergo in response to the requirement to adhere to the extrusion rate flow adjustment.

src/libslic3r/ExtrusionRole.cpp

@@ -12,37 +12,6 @@
 
 namespace Slic3r {
 
-
-/* IG For reference only. Defined in Extrusion Entity hpp. Do not uncomment:
-
-// Each ExtrusionRole value identifies a distinct set of { extruder, speed }
-enum ExtrusionRole : uint8_t {
-    erNone,
-    erPerimeter,
-    erExternalPerimeter,
-    erOverhangPerimeter,
-    erInternalInfill,
-    erSolidInfill,
-    erTopSolidInfill,
-    erBottomSurface,
-    erIroning,
-    erBridgeInfill,
-    erInternalBridgeInfill,
-    erGapFill,
-    erSkirt,
-    erBrim,
-    erSupportMaterial,
-    erSupportMaterialInterface,
-    erSupportTransition,
-    erWipeTower,
-    erCustom,
-    // Extrusion role for a collection with multiple extrusion roles.
-    erMixed,
-    erCount
-};
-
-*/
-
 // Convert a rich bitmask based ExtrusionRole to a less expressive ordinal GCodeExtrusionRole.
 // GCodeExtrusionRole is to be serialized into G-code and deserialized by G-code viewer,
 GCodeExtrusionRole extrusion_role_to_gcode_extrusion_role(ExtrusionRole role)

src/libslic3r/GCode/PressureEqualizer.cpp

@@ -24,10 +24,6 @@ static const std::string EXTRUDE_END_TAG = ";_EXTRUDE_END";
 static const std::string EXTRUDE_SET_SPEED_TAG = ";_EXTRUDE_SET_SPEED";
 static const std::string EXTERNAL_PERIMETER_TAG = ";_EXTERNAL_PERIMETER";
 
-// Maximum segment length to split a long segment if the initial and the final flow rate differ.
-// Smaller value means a smoother transition between two different flow rates.
-static constexpr float max_segment_length = 1.0f;
-
 // For how many GCode lines back will adjust a flow rate from the latest line.
 // Bigger values affect the GCode export speed a lot, and smaller values could
 // affect how distant will be propagated a flow rate adjustment.
@@ -52,6 +48,8 @@ PressureEqualizer::PressureEqualizer(const Slic3r::GCodeConfig &config) : m_use_
     m_current_extrusion_role = GCodeExtrusionRole::None;
     // Expect the first command to fill the nozzle (deretract).
     m_retracted = true;
+    
+    m_max_segment_length = 2.f;
 
     // Calculate filamet crossections for the multiple extruders.
     m_filament_crossections.clear();
@@ -67,6 +65,7 @@ PressureEqualizer::PressureEqualizer(const Slic3r::GCodeConfig &config) : m_use_
     if(config.max_volumetric_extrusion_rate_slope.value > 0){
 		m_max_volumetric_extrusion_rate_slope_positive = float(config.max_volumetric_extrusion_rate_slope.value) * 60.f * 60.f;
     	m_max_volumetric_extrusion_rate_slope_negative = float(config.max_volumetric_extrusion_rate_slope.value) * 60.f * 60.f;
+    	m_max_segment_length = float(config.max_volumetric_extrusion_rate_slope_segment_length.value);
     }
 
     for (ExtrusionRateSlope &extrusion_rate_slope : m_max_volumetric_extrusion_rate_slopes) {
@@ -489,7 +488,7 @@ void PressureEqualizer::output_gcode_line(const size_t line_idx)
 
     // Emit the line with lowered extrusion rates.
     float l = line.dist_xyz();
-    if (auto nSegments = size_t(ceil(l / max_segment_length)); nSegments == 1) { // Just update this segment.
+    if (auto nSegments = size_t(ceil(l / m_max_segment_length)); nSegments == 1) { // Just update this segment.
         push_line_to_output(line_idx, line.feedrate() * line.volumetric_correction_avg(), comment);
     } else {
         bool accelerating = line.volumetric_extrusion_rate_start < line.volumetric_extrusion_rate_end;
@@ -512,11 +511,11 @@ void PressureEqualizer::output_gcode_line(const size_t line_idx)
             // One may achieve higher print speeds if part of the segment is not speed limited.
             l_acc    = t_acc * feed_avg;
             l_steady = l - l_acc;
-            if (l_steady < 0.5f * max_segment_length) {
+            if (l_steady < 0.5f * m_max_segment_length) {
                 l_acc    = l;
                 l_steady = 0.f;
             } else
-                nSegments = size_t(ceil(l_acc / max_segment_length));
+                nSegments = size_t(ceil(l_acc / m_max_segment_length));
         }
         float pos_start[5];
         float pos_end[5];

src/libslic3r/GCode/PressureEqualizer.hpp

@@ -86,6 +86,10 @@ private:
     bool                            m_retracted;
     bool                            m_use_relative_e_distances;
 
+	// Maximum segment length to split a long segment if the initial and the final flow rate differ.
+	// Smaller value means a smoother transition between two different flow rates.
+    float                           m_max_segment_length;
+
     // Indicate if extrude set speed block was opened using the tag ";_EXTRUDE_SET_SPEED"
     // or not (not opened, or it was closed using the tag ";_EXTRUDE_END").
     bool                            opened_extrude_set_speed_block = false;

src/libslic3r/Preset.cpp

@@ -725,7 +725,7 @@ static std::vector<std::string> s_Preset_print_options {
     "ironing_type", "ironing_pattern", "ironing_flow", "ironing_speed", "ironing_spacing",
     "max_travel_detour_distance",
     "fuzzy_skin", "fuzzy_skin_thickness", "fuzzy_skin_point_distance",
-    "max_volumetric_extrusion_rate_slope",
+    "max_volumetric_extrusion_rate_slope", "max_volumetric_extrusion_rate_slope_segment_length",
     "inner_wall_speed", "outer_wall_speed", "sparse_infill_speed", "internal_solid_infill_speed",
     "top_surface_speed", "support_speed", "support_object_xy_distance", "support_interface_speed",
     "bridge_speed", "internal_bridge_speed", "gap_infill_speed", "travel_speed", "travel_speed_z", "initial_layer_speed",

src/libslic3r/Print.cpp

@@ -129,6 +129,7 @@ bool Print::invalidate_state_by_config_options(const ConfigOptionResolver & /* n
         "printable_height",
         "slow_down_min_speed",
         "max_volumetric_extrusion_rate_slope",
+        "max_volumetric_extrusion_rate_slope_segment_length",
         "reduce_infill_retraction",
         "filename_format",
         "retraction_minimum_travel",

src/libslic3r/PrintConfig.cpp

@@ -2490,6 +2490,17 @@ def = this->add("filament_loading_speed", coFloats);
     def->min = 0;
     def->mode = comAdvanced;
     def->set_default_value(new ConfigOptionFloat(0));
+    
+    def = this->add("max_volumetric_extrusion_rate_slope_segment_length", coInt);
+    def->label = L("Smoothing segment length");
+    def->tooltip = L("A lower value results in smoother extrusion rate transitions. However, this results in a significantly larger gcode file "
+    				 "and more instructions for the printer to process. \n\n"
+    				 "Default value of 2 works well for most cases. If your printer is stuttering, increase this value to reduce the number of adjustments made\n\n"
+    				 "Allowed values: 1-5");
+    def->min = 1;
+    def->max = 5;
+    def->mode = comAdvanced;
+    def->set_default_value(new ConfigOptionInt(2));
 
     def = this->add("fan_min_speed", coInts);
     def->label = L("Fan speed");

src/libslic3r/PrintConfig.hpp

@@ -883,6 +883,7 @@ PRINT_CONFIG_CLASS_DEFINE(
     ((ConfigOptionString,              layer_change_gcode))
 
     ((ConfigOptionFloat,               max_volumetric_extrusion_rate_slope))
+    ((ConfigOptionInt,               max_volumetric_extrusion_rate_slope_segment_length))
     
     ((ConfigOptionPercents,            retract_before_wipe))
     ((ConfigOptionFloats,              retraction_length))

src/slic3r/GUI/ConfigManipulation.cpp

@@ -510,8 +510,15 @@ void ConfigManipulation::toggle_print_fff_options(DynamicPrintConfig *config, co
     auto gcflavor = preset_bundle->printers.get_edited_preset().config.option<ConfigOptionEnum<GCodeFlavor>>("gcode_flavor")->value;
     
     bool have_volumetric_extrusion_rate_slope = config->option<ConfigOptionFloat>("max_volumetric_extrusion_rate_slope")->value > 0;
+    int have_volumetric_extrusion_rate_slope_segment_length = config->option<ConfigOptionInt>("max_volumetric_extrusion_rate_slope_segment_length")->value;
     toggle_field("enable_arc_fitting", !have_volumetric_extrusion_rate_slope);
+    toggle_line("max_volumetric_extrusion_rate_slope_segment_length", have_volumetric_extrusion_rate_slope);
     if(have_volumetric_extrusion_rate_slope) config->set_key_value("enable_arc_fitting", new ConfigOptionBool(false));
+    if(have_volumetric_extrusion_rate_slope_segment_length==0) {
+    	DynamicPrintConfig new_conf = *config;
+        new_conf.set_key_value("max_volumetric_extrusion_rate_slope_segment_length", new ConfigOptionInt(1));
+        apply(config, &new_conf);    
+    }
     
     bool have_perimeters = config->opt_int("wall_loops") > 0;
     for (auto el : { "extra_perimeters_on_overhangs", "ensure_vertical_shell_thickness", "detect_thin_wall", "detect_overhang_wall",

src/slic3r/GUI/Tab.cpp

@@ -1998,6 +1998,7 @@ void TabPrint::build()
         
         optgroup = page->new_optgroup(L("Advanced"), L"param_advanced", 15);
         optgroup->append_single_option_line("max_volumetric_extrusion_rate_slope");
+        optgroup->append_single_option_line("max_volumetric_extrusion_rate_slope_segment_length");
 
     page = add_options_page(L("Support"), "support");
         optgroup = page->new_optgroup(L("Support"), L"param_support");