Configurable volumetric extrusion rate slope.

xs/src/libslic3r/GCode/PressureEqualizer.cpp

@@ -44,11 +44,13 @@ void GCodePressureEqualizer::reset()
     }
 
     m_max_segment_length = 20.f;
-    // Volumetric rate of a 0.45mm x 0.2mm extrusion at 60mm/min XY movement: 0.45*0.2*60*60=5.4*60 = 324 mm^3/min
-    // Volumetric rate of a 0.45mm x 0.2mm extrusion at 20mm/min XY movement: 0.45*0.2*20*60=1.8*60 = 108 mm^3/min
-    // Slope of the volumetric rate, changing from 20mm^3/min to 60mm^3/min over 2 seconds: (5.4-1.8)*60*60/2=60*60*1.8 = 6480 mm^3/min^2
-    m_max_volumetric_extrusion_rate_slope_positive = 6480.f;
-    m_max_volumetric_extrusion_rate_slope_negative = 6480.f;
+    // Volumetric rate of a 0.45mm x 0.2mm extrusion at 60mm/s XY movement: 0.45*0.2*60*60=5.4*60 = 324 mm^3/min
+    // Volumetric rate of a 0.45mm x 0.2mm extrusion at 20mm/s XY movement: 0.45*0.2*20*60=1.8*60 = 108 mm^3/min
+    // Slope of the volumetric rate, changing from 20mm/s to 60mm/s over 2 seconds: (5.4-1.8)*60*60/2=60*60*1.8 = 6480 mm^3/min^2 = 1.8 mm^3/s^2
+    m_max_volumetric_extrusion_rate_slope_positive = (this->m_config == NULL) ? 6480.f :
+        this->m_config->max_volumetric_extrusion_rate_slope_positive.value * 60. * 60.;
+    m_max_volumetric_extrusion_rate_slope_negative = (this->m_config == NULL) ? 6480.f :
+        this->m_config->max_volumetric_extrusion_rate_slope_negative.value * 60. * 60.;
 
     for (size_t i = 0; i < numExtrusionRoles; ++ i) {
         m_max_volumetric_extrusion_rate_slopes[i].negative = m_max_volumetric_extrusion_rate_slope_negative;

xs/src/libslic3r/PrintConfig.cpp

@@ -595,6 +595,24 @@ PrintConfigDef::PrintConfigDef()
     def->min = 0;
     def->default_value = new ConfigOptionFloat(0);
 
+    def = this->add("max_volumetric_extrusion_rate_slope_positive", coFloat);
+    def->label = "Max volumetric slope positive";
+    def->tooltip = "This experimental setting is used to limit the speed of change in extrusion rate. A value of 1.8 mm³/s² ensures, that a change from the extrusion rate "
+                   "of 1.8 mm³/s (0.45mm extrusion width, 0.2mm extrusion height, feedrate 20 mm/s) to 5.4 mm³/s (feedrate 60 mm/s) will take at least 2 seconds.";
+    def->sidetext = "mm³/s²";
+    def->cli = "max-volumetric-extrusion-rate-slope-positive=f";
+    def->min = 0;
+    def->default_value = new ConfigOptionFloat(0);
+
+    def = this->add("max_volumetric_extrusion_rate_slope_negative", coFloat);
+    def->label = "Max volumetric slope negative";
+    def->tooltip = "This experimental setting is used to limit the speed of change in extrusion rate. A value of 1.8 mm³/s² ensures, that a change from the extrusion rate "
+                   "of 1.8 mm³/s (0.45mm extrusion width, 0.2mm extrusion height, feedrate 20 mm/s) to 5.4 mm³/s (feedrate 60 mm/s) will take at least 2 seconds.";
+    def->sidetext = "mm³/s²";
+    def->cli = "max-volumetric-extrusion-rate-slope-negative=f";
+    def->min = 0;
+    def->default_value = new ConfigOptionFloat(0);
+
     def = this->add("min_fan_speed", coInt);
     def->label = "Min";
     def->tooltip = "This setting represents the minimum PWM your fan needs to work.";

xs/src/libslic3r/PrintConfig.hpp

@@ -289,6 +289,8 @@ class GCodeConfig : public virtual StaticPrintConfig
     ConfigOptionString              layer_gcode;
     ConfigOptionFloat               max_print_speed;
     ConfigOptionFloat               max_volumetric_speed;
+    ConfigOptionFloat               max_volumetric_extrusion_rate_slope_positive;
+    ConfigOptionFloat               max_volumetric_extrusion_rate_slope_negative;
     ConfigOptionFloat               pressure_advance;
     ConfigOptionFloats              retract_length;
     ConfigOptionFloats              retract_length_toolchange;
@@ -321,6 +323,8 @@ class GCodeConfig : public virtual StaticPrintConfig
         OPT_PTR(layer_gcode);
         OPT_PTR(max_print_speed);
         OPT_PTR(max_volumetric_speed);
+        OPT_PTR(max_volumetric_extrusion_rate_slope_positive);
+        OPT_PTR(max_volumetric_extrusion_rate_slope_negative);
         OPT_PTR(pressure_advance);
         OPT_PTR(retract_length);
         OPT_PTR(retract_length_toolchange);