Made the support interface contact loops configurable.

lib/Slic3r/GUI/Tab.pm

@@ -533,7 +533,7 @@ sub build {
         support_material support_material_threshold support_material_enforce_layers
         raft_layers
         support_material_pattern support_material_with_sheath support_material_spacing support_material_synchronize_layers support_material_angle
-        support_material_interface_layers support_material_interface_spacing
+        support_material_interface_layers support_material_interface_spacing support_material_interface_contact_loops
         support_material_contact_distance support_material_buildplate_only dont_support_bridges
         notes
         complete_objects extruder_clearance_radius extruder_clearance_height
@@ -646,6 +646,7 @@ sub build {
             $optgroup->append_single_option_line('support_material_angle');
             $optgroup->append_single_option_line('support_material_interface_layers');
             $optgroup->append_single_option_line('support_material_interface_spacing');
+            $optgroup->append_single_option_line('support_material_interface_contact_loops');
             $optgroup->append_single_option_line('support_material_buildplate_only');
             $optgroup->append_single_option_line('dont_support_bridges');
             $optgroup->append_single_option_line('support_material_synchronize_layers');
@@ -916,7 +917,7 @@ sub _update {
             support_material_extrusion_width support_material_contact_distance);
     $self->get_field($_)->toggle($have_support_material && $have_support_interface)
         for qw(support_material_interface_spacing support_material_interface_extruder
-            support_material_interface_speed);
+            support_material_interface_speed support_material_interface_contact_loops);
     
     $self->get_field('perimeter_extrusion_width')->toggle($have_perimeters || $have_skirt || $have_brim);
     $self->get_field('support_material_extruder')->toggle($have_support_material || $have_skirt);

lib/Slic3r/Print/SupportMaterial.pm

@@ -640,7 +640,7 @@ sub generate_toolpaths {
     my $interface_flow  = $self->interface_flow;
     
     # shape of contact area
-    my $contact_loops   = 1;
+    my $contact_loops   = $self->object_config->support_material_interface_contact_loops ? 1 : 0;
     my $circle_radius   = 1.5 * $interface_flow->scaled_width;
     my $circle_distance = 3 * $circle_radius;
     my $circle          = Slic3r::Polygon->new(map [ $circle_radius * cos $_, $circle_radius * sin $_ ],
@@ -704,7 +704,10 @@ sub generate_toolpaths {
             # if no interface layers were requested we treat the contact layer
             # exactly as a generic base layer
             push @$base, @$contact;
-        } elsif (@$contact && $contact_loops > 0) {
+        } elsif ($contact_loops == 0) {
+            # No contact loops, but some interface layers. Print the contact layer as a normal interface layer.
+            push @$interface, @$contact;
+        } elsif (@$contact) {
             # generate the outermost loop
             
             # find centerline of the external loop (or any other kind of extrusions should the loop be skipped)

xs/src/libslic3r/PrintConfig.cpp

@@ -1177,6 +1177,13 @@ PrintConfigDef::PrintConfigDef()
     def->cli = "support-material-extrusion-width=s";
     def->default_value = new ConfigOptionFloatOrPercent(0, false);
 
+    def = this->add("support_material_interface_contact_loops", coBool);
+    def->label = "Interface circles";
+    def->category = "Support material";
+    def->tooltip = "Cover the top most interface layer with contact loops";
+    def->cli = "support-material-interface-contact-loops!";
+    def->default_value = new ConfigOptionBool(true);
+
     def = this->add("support_material_interface_extruder", coInt);
     def->label = "Support material/raft interface extruder";
     def->category = "Extruders";
@@ -1252,7 +1259,7 @@ PrintConfigDef::PrintConfigDef()
     def->category = "Support material";
     def->tooltip = "Synchronize support layers with the object print layers. This is useful with multi-material printers, where the extruder switch is expensive.";
     def->cli = "support-material-synchronize-layers!";
-    def->default_value = new ConfigOptionBool(true);
+    def->default_value = new ConfigOptionBool(false);
 
     def = this->add("support_material_threshold", coInt);
     def->label = "Overhang threshold";

xs/src/libslic3r/PrintConfig.hpp

@@ -153,6 +153,7 @@ class PrintObjectConfig : public virtual StaticPrintConfig
     ConfigOptionInt                 support_material_enforce_layers;
     ConfigOptionInt                 support_material_extruder;
     ConfigOptionFloatOrPercent      support_material_extrusion_width;
+    ConfigOptionBool                support_material_interface_contact_loops;
     ConfigOptionInt                 support_material_interface_extruder;
     ConfigOptionInt                 support_material_interface_layers;
     ConfigOptionFloat               support_material_interface_spacing;
@@ -186,6 +187,7 @@ class PrintObjectConfig : public virtual StaticPrintConfig
         OPT_PTR(support_material_buildplate_only);
         OPT_PTR(support_material_contact_distance);
         OPT_PTR(support_material_enforce_layers);
+        OPT_PTR(support_material_interface_contact_loops);
         OPT_PTR(support_material_extruder);
         OPT_PTR(support_material_extrusion_width);
         OPT_PTR(support_material_interface_extruder);

xs/src/libslic3r/PrintObject.cpp

@@ -197,6 +197,7 @@ PrintObject::invalidate_state_by_config_options(const std::vector<t_config_optio
             || *opt_key == "support_material_extruder"
             || *opt_key == "support_material_extrusion_width"
             || *opt_key == "support_material_interface_layers"
+            || *opt_key == "support_material_interface_contact_loops"
             || *opt_key == "support_material_interface_extruder"
             || *opt_key == "support_material_interface_spacing"
             || *opt_key == "support_material_interface_speed"