New option to force a solid layer every given number of layers. #617

README.markdown

@@ -153,7 +153,9 @@ The author of the Silk icon set is Mark James.
         --first-layer-height Layer height for first layer (mm or %, default: 100%)
         --infill-every-layers
                             Infill every N layers (default: 1)
-      
+        --solid-infill-every-layers
+                            Force a solid layer every N layers (default: 0)
+    
       Print options:
         --perimeters        Number of perimeters/horizontal skins (range: 0+, default: 3)
         --solid-layers      Number of solid layers to do for top/bottom surfaces

lib/Slic3r/Config.pm

@@ -353,6 +353,15 @@ our $Options = {
         min     => 1,
         default => 1,
     },
+    'solid_infill_every_layers' => {
+        label   => 'Solid infill every',
+        tooltip => 'This feature allows to force a solid layer every given number of layers. Zero to disable.',
+        sidetext => 'layers',
+        cli     => 'solid-infill-every-layers=i',
+        type    => 'i',
+        min     => 0,
+        default => 0,
+    },
     
     # flow options
     'extrusion_width' => {

lib/Slic3r/GUI/Tab.pm

@@ -401,7 +401,7 @@ sub build {
         },
         {
             title => 'Advanced',
-            options => [qw(infill_every_layers fill_angle solid_infill_below_area only_retract_when_crossing_perimeters)],
+            options => [qw(infill_every_layers solid_infill_every_layers fill_angle solid_infill_below_area only_retract_when_crossing_perimeters)],
         },
     ]);
     

lib/Slic3r/Print/Object.pm

@@ -329,6 +329,12 @@ sub discover_horizontal_shells {
     for my $region_id (0 .. ($self->print->regions_count-1)) {
         for (my $i = 0; $i < $self->layer_count; $i++) {
             my $layerm = $self->layers->[$i]->regions->[$region_id];
+            
+            if ($Slic3r::Config->solid_infill_every_layers && ($i % $Slic3r::Config->solid_infill_every_layers) == 0) {
+                $_->surface_type(S_TYPE_INTERNALSOLID)
+                    for grep $_->surface_type == S_TYPE_INTERNAL, @{$layerm->fill_surfaces};
+            }
+            
             foreach my $type (S_TYPE_TOP, S_TYPE_BOTTOM) {
                 # find surfaces of current type for current layer
                 # and offset them to take perimeters into account

slic3r.pl

@@ -201,6 +201,8 @@ $j
     --first-layer-height Layer height for first layer (mm or %, default: $config->{first_layer_height})
     --infill-every-layers
                         Infill every N layers (default: $config->{infill_every_layers})
+    --solid-infill-every-layers
+                        Force a solid layer every N layers (default: $config->{solid_infill_every_layers})
   
   Print options:
     --perimeters        Number of perimeters/horizontal skins (range: 0+, default: $config->{perimeters})