Use perimeter extruder for brim. #618

README.md

@@ -351,11 +351,11 @@ The author of the Silk icon set is Mark James.
         --extruder-offset   Offset of each extruder, if firmware doesn't handle the displacement
                             (can be specified multiple times, default: 0x0)
         --perimeter-extruder
-                            Extruder to use for perimeters (1+, default: 1)
+                            Extruder to use for perimeters and brim (1+, default: 1)
         --infill-extruder   Extruder to use for infill (1+, default: 1)
         --solid-infill-extruder   Extruder to use for solid infill (1+, default: 1)
         --support-material-extruder
-                            Extruder to use for support material (1+, default: 1)
+                            Extruder to use for support material, raft and skirt (1+, default: 1)
         --support-material-interface-extruder
                             Extruder to use for support material interface (1+, default: 1)
                             --ooze-prevention   Drop temperature and park extruders outside a full skirt for automatic wiping

lib/Slic3r/Print.pm

@@ -332,9 +332,9 @@ sub make_brim {
     }
     $self->status_cb->(88, "Generating brim");
     
-    # brim is only printed on first layer and uses support material extruder
+    # brim is only printed on first layer and uses perimeter extruder
     my $first_layer_height = $self->skirt_first_layer_height;
-    my $flow = $self->skirt_flow;
+    my $flow = $self->brim_flow;
     my $mm3_per_mm = $flow->mm3_per_mm;
     
     my $grow_distance = $flow->scaled_width / 2;

lib/Slic3r/Print/GCode.pm

@@ -348,7 +348,7 @@ sub process_layer {
     
     # extrude brim
     if (!$self->_brim_done) {
-        $gcode .= $self->_gcodegen->set_extruder($self->print->objects->[0]->config->support_material_extruder-1);
+        $gcode .= $self->_gcodegen->set_extruder($self->print->regions->[0]->config->perimeter_extruder-1);
         $self->_gcodegen->set_origin(Slic3r::Pointf->new(0,0));
         $self->_gcodegen->avoid_crossing_perimeters->use_external_mp(1);
         $gcode .= $self->_gcodegen->extrude_loop($_, 'brim', $object->config->support_material_speed)

slic3r.pl

@@ -503,11 +503,11 @@ $j
     --extruder-offset   Offset of each extruder, if firmware doesn't handle the displacement
                         (can be specified multiple times, default: 0x0)
     --perimeter-extruder
-                        Extruder to use for perimeters (1+, default: $config->{perimeter_extruder})
+                        Extruder to use for perimeters and brim (1+, default: $config->{perimeter_extruder})
     --infill-extruder   Extruder to use for infill (1+, default: $config->{infill_extruder})
     --solid-infill-extruder   Extruder to use for solid infill (1+, default: $config->{solid_infill_extruder})
     --support-material-extruder
-                        Extruder to use for support material (1+, default: $config->{support_material_extruder})
+                        Extruder to use for support material, raft and skirt (1+, default: $config->{support_material_extruder})
     --support-material-interface-extruder
                         Extruder to use for support material interface (1+, default: $config->{support_material_interface_extruder})
     --ooze-prevention   Drop temperature and park extruders outside a full skirt for automatic wiping

xs/src/libslic3r/Print.cpp

@@ -669,11 +669,12 @@ Print::total_bounding_box() const
     }
     
     // consider brim and skirt
-    Flow skirt_flow = this->skirt_flow();
     if (this->config.brim_width.value > 0) {
-        extra = std::max(extra, this->config.brim_width.value + skirt_flow.width/2);
+        Flow brim_flow = this->brim_flow();
+        extra = std::max(extra, this->config.brim_width.value + brim_flow.width/2);
     }
     if (this->config.skirts.value > 0) {
+        Flow skirt_flow = this->skirt_flow();
         extra = std::max(
             extra,
             this->config.brim_width.value
@@ -696,12 +697,37 @@ Print::skirt_first_layer_height() const
     return this->objects.front()->config.get_abs_value("first_layer_height");
 }
 
+Flow
+Print::brim_flow() const
+{
+    ConfigOptionFloatOrPercent width = this->config.first_layer_extrusion_width;
+    if (width.value == 0) width = this->regions.front()->config.perimeter_extrusion_width;
+    
+    /* We currently use a random region's perimeter extruder.
+       While this works for most cases, we should probably consider all of the perimeter
+       extruders and take the one with, say, the smallest index.
+       The same logic should be applied to the code that selects the extruder during G-code
+       generation as well. */
+    return Flow::new_from_config_width(
+        frPerimeter,
+        width, 
+        this->config.nozzle_diameter.get_at(this->regions.front()->config.perimeter_extruder-1),
+        this->skirt_first_layer_height(),
+        0
+    );
+}
+
 Flow
 Print::skirt_flow() const
 {
     ConfigOptionFloatOrPercent width = this->config.first_layer_extrusion_width;
     if (width.value == 0) width = this->regions.front()->config.perimeter_extrusion_width;
     
+    /* We currently use a random object's support material extruder.
+       While this works for most cases, we should probably consider all of the support material
+       extruders and take the one with, say, the smallest index;
+       The same logic should be applied to the code that selects the extruder during G-code
+       generation as well. */
     return Flow::new_from_config_width(
         frPerimeter,
         width, 

xs/src/libslic3r/Print.hpp

@@ -188,6 +188,7 @@ class Print
     BoundingBox bounding_box() const;
     BoundingBox total_bounding_box() const;
     double skirt_first_layer_height() const;
+    Flow brim_flow() const;
     Flow skirt_flow() const;
     
     std::set<size_t> extruders() const;

xs/src/libslic3r/PrintConfig.cpp

@@ -529,7 +529,7 @@ PrintConfigDef::build_def() {
     Options["perimeter_extruder"].type = coInt;
     Options["perimeter_extruder"].label = "Perimeter extruder";
     Options["perimeter_extruder"].category = "Extruders";
-    Options["perimeter_extruder"].tooltip = "The extruder to use when printing perimeters. First extruder is 1.";
+    Options["perimeter_extruder"].tooltip = "The extruder to use when printing perimeters and brim. First extruder is 1.";
     Options["perimeter_extruder"].cli = "perimeter-extruder=i";
     Options["perimeter_extruder"].aliases.push_back("perimeters_extruder");
     Options["perimeter_extruder"].min = 1;
@@ -781,7 +781,7 @@ PrintConfigDef::build_def() {
     Options["support_material_extruder"].type = coInt;
     Options["support_material_extruder"].label = "Support material extruder";
     Options["support_material_extruder"].category = "Extruders";
-    Options["support_material_extruder"].tooltip = "The extruder to use when printing support material. This affects brim and raft too.";
+    Options["support_material_extruder"].tooltip = "The extruder to use when printing support material, raft and skirt.";
     Options["support_material_extruder"].cli = "support-material-extruder=i";
     Options["support_material_extruder"].min = 1;
 

xs/xsp/Print.xsp

@@ -190,6 +190,7 @@ _constant()
     Clone<BoundingBox> bounding_box();
     Clone<BoundingBox> total_bounding_box();
     double skirt_first_layer_height();
+    Clone<Flow> brim_flow();
     Clone<Flow> skirt_flow();
 %{