Seperate the skin and infill to give them different speeds. Also change the printing order of this to handle pressure differences better. Which should increase print quality on advanced profiles.

src/fffProcessor.h

@@ -25,7 +25,8 @@ private:
     GCodePathConfig skirtConfig;
     GCodePathConfig inset0Config;
     GCodePathConfig insetXConfig;
-    GCodePathConfig fillConfig;
+    GCodePathConfig infillConfig;
+    GCodePathConfig skinConfig;
     GCodePathConfig supportConfig;
 public:
     fffProcessor(ConfigSettings& config)
@@ -98,7 +99,8 @@ private:
         skirtConfig.setData(config.printSpeed, config.extrusionWidth, "SKIRT");
         inset0Config.setData(config.inset0Speed, config.extrusionWidth, "WALL-OUTER");
         insetXConfig.setData(config.insetXSpeed, config.extrusionWidth, "WALL-INNER");
-        fillConfig.setData(config.infillSpeed, config.extrusionWidth, "FILL");
+        infillConfig.setData(config.infillSpeed, config.extrusionWidth, "FILL");
+        skinConfig.setData(config.skinSpeed, config.extrusionWidth, "FILL");
         supportConfig.setData(config.printSpeed, config.extrusionWidth, "SUPPORT");
 
         for(unsigned int n=1; n<MAX_EXTRUDERS;n++)
@@ -441,14 +443,16 @@ private:
                 skirtConfig.setData(SPEED_SMOOTH(config.printSpeed), extrusionWidth, "SKIRT");
                 inset0Config.setData(SPEED_SMOOTH(config.inset0Speed), extrusionWidth, "WALL-OUTER");
                 insetXConfig.setData(SPEED_SMOOTH(config.insetXSpeed), extrusionWidth, "WALL-INNER");
-                fillConfig.setData(SPEED_SMOOTH(config.infillSpeed), extrusionWidth,  "FILL");
+                infillConfig.setData(SPEED_SMOOTH(config.infillSpeed), extrusionWidth,  "FILL");
+                skinConfig.setData(SPEED_SMOOTH(config.skinSpeed), extrusionWidth,  "SKIN");
                 supportConfig.setData(SPEED_SMOOTH(config.printSpeed), extrusionWidth, "SUPPORT");
 #undef SPEED_SMOOTH
             }else{
                 skirtConfig.setData(config.printSpeed, extrusionWidth, "SKIRT");
                 inset0Config.setData(config.inset0Speed, extrusionWidth, "WALL-OUTER");
                 insetXConfig.setData(config.insetXSpeed, extrusionWidth, "WALL-INNER");
-                fillConfig.setData(config.infillSpeed, extrusionWidth, "FILL");
+                infillConfig.setData(config.infillSpeed, extrusionWidth, "FILL");
+                skinConfig.setData(config.skinSpeed, extrusionWidth, "SKIN");
                 supportConfig.setData(config.printSpeed, extrusionWidth, "SUPPORT");
             }
 
@@ -596,6 +600,49 @@ private:
             else
                 gcodeLayer.setAlwaysRetract(true);
 
+            Polygons infillPolygons;
+            int fillAngle = 45;
+            if (layerNr & 1)
+                fillAngle += 90;
+            int extrusionWidth = config.extrusionWidth;
+            if (layerNr == 0)
+                extrusionWidth = config.layer0extrusionWidth;
+            if (config.sparseInfillLineDistance > 0)
+            {
+                switch (config.infillPattern)
+                {
+                    case INFILL_AUTOMATIC:
+                        generateAutomaticInfill(
+                            part->sparseOutline, infillPolygons, extrusionWidth,
+                            config.sparseInfillLineDistance,
+                            config.infillOverlap, fillAngle);
+                        break;
+
+                    case INFILL_GRID:
+                        generateGridInfill(part->sparseOutline, infillPolygons,
+                                           extrusionWidth,
+                                           config.sparseInfillLineDistance,
+                                           config.infillOverlap, fillAngle);
+                        break;
+
+                    case INFILL_LINES:
+                        generateLineInfill(part->sparseOutline, infillPolygons,
+                                           extrusionWidth,
+                                           config.sparseInfillLineDistance,
+                                           config.infillOverlap, fillAngle);
+                        break;
+
+                    case INFILL_CONCENTRIC:
+                        generateConcentricInfill(
+                            part->sparseOutline, infillPolygons,
+                            config.sparseInfillLineDistance);
+                        break;
+                }
+            }
+
+            gcodeLayer.addPolygonsByOptimizer(infillPolygons, &infillConfig);
+            //sendPolygonsToGui("infill", layerNr, layer->z, fillPolygons);
+
             if (config.insetCount > 0)
             {
                 if (config.spiralizeMode)
@@ -613,56 +660,17 @@ private:
                         gcodeLayer.addPolygonsByOptimizer(part->insets[insetNr], &insetXConfig);
                 }
             }
-
-            Polygons fillPolygons;
-            int fillAngle = 45;
-            if (layerNr & 1)
-                fillAngle += 90;
-            int extrusionWidth = config.extrusionWidth;
-            if (layerNr == 0)
-                extrusionWidth = config.layer0extrusionWidth;
+            
+            Polygons skinPolygons;
             for(Polygons outline : part->skinOutline.splitIntoParts())
             {
                 int bridge = -1;
                 if (layerNr > 0)
                     bridge = bridgeAngle(outline, &storage.volumes[volumeIdx].layers[layerNr-1]);
-                generateLineInfill(outline, fillPolygons, extrusionWidth, extrusionWidth, config.infillOverlap, (bridge > -1) ? bridge : fillAngle);
+                generateLineInfill(outline, skinPolygons, extrusionWidth, extrusionWidth, config.infillOverlap, (bridge > -1) ? bridge : fillAngle);
             }
-            if (config.sparseInfillLineDistance > 0)
-            {
-                switch (config.infillPattern)
-                {
-                    case INFILL_AUTOMATIC:
-                        generateAutomaticInfill(
-                            part->sparseOutline, fillPolygons, extrusionWidth,
-                            config.sparseInfillLineDistance,
-                            config.infillOverlap, fillAngle);
-                        break;
+            gcodeLayer.addPolygonsByOptimizer(skinPolygons, &skinConfig);
 
-                    case INFILL_GRID:
-                        generateGridInfill(part->sparseOutline, fillPolygons,
-                                           extrusionWidth,
-                                           config.sparseInfillLineDistance,
-                                           config.infillOverlap, fillAngle);
-                        break;
-
-                    case INFILL_LINES:
-                        generateLineInfill(part->sparseOutline, fillPolygons,
-                                           extrusionWidth,
-                                           config.sparseInfillLineDistance,
-                                           config.infillOverlap, fillAngle);
-                        break;
-
-                    case INFILL_CONCENTRIC:
-                        generateConcentricInfill(
-                            part->sparseOutline, fillPolygons,
-                            config.sparseInfillLineDistance);
-                        break;
-                }
-            }
-
-            gcodeLayer.addPolygonsByOptimizer(fillPolygons, &fillConfig);
-            //sendPolygonsToGui("infill", layerNr, layer->z, fillPolygons);
 
             //After a layer part, make sure the nozzle is inside the comb boundary, so we do not retract on the perimeter.
             if (!config.spiralizeMode || static_cast<int>(layerNr) < config.downSkinCount)

src/settings.cpp

@@ -43,6 +43,7 @@ ConfigSettings::ConfigSettings()
     SETTING(infillOverlap, 15);
     SETTING(infillSpeed, 50);
     SETTING(infillPattern, INFILL_AUTOMATIC);
+    SETTING(skinSpeed, 50);
 
     SETTING(supportType, SUPPORT_TYPE_GRID);
     SETTING(supportAngle, -1);

src/settings.h

@@ -156,6 +156,7 @@ public:
     int infillOverlap;
     int infillSpeed;
     int infillPattern;
+    int skinSpeed;
 
     //Support material
     int supportType;