New option to configure the threshold for enforcing solid infill. #224

README.markdown

@@ -170,6 +170,9 @@ The author of the Silk icon set is Mark James.
         --layer-gcode       Load layer-change G-code from the supplied file (default: nothing).
         --extra-perimeters  Add more perimeters when needed (default: yes)
         --randomize-start   Randomize starting point across layers (default: yes)
+        --solid-infill-below-area
+                            Force solid infill when a region has a smaller area than this threshold
+                            (mm^2, default: 70)
       
        Support material options:
         --support-material  Generate support material for overhangs

lib/Slic3r/Config.pm

@@ -449,6 +449,14 @@ our $Options = {
         max     => 359,
         default => 45,
     },
+    'solid_infill_below_area' => {
+        label   => 'Solid infill threshold area',
+        tooltip => 'Force solid infill for regions having a smaller area than the specified threshold.',
+        sidetext => 'mm²',
+        cli     => 'solid-infill-below-area=f',
+        type    => 'f',
+        default => 70,
+    },
     'extra_perimeters' => {
         label   => 'Generate extra perimeters when needed',
         cli     => 'extra-perimeters!',

lib/Slic3r/GUI/Tab.pm

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

lib/Slic3r/Layer.pm

@@ -365,7 +365,7 @@ sub prepare_fill_surfaces {
         
     # turn too small internal regions into solid regions
     {
-        my $min_area = ((7 * $self->infill_flow->spacing / &Slic3r::SCALING_FACTOR)**2) * PI;
+        my $min_area = scale scale $Slic3r::Config->solid_infill_below_area; # scaling an area requires two calls!
         my @small = grep $_->surface_type == S_TYPE_INTERNAL && $_->expolygon->contour->area <= $min_area, @surfaces;
         $_->surface_type(S_TYPE_INTERNALSOLID) for @small;
         Slic3r::debugf "identified %d small surfaces at layer %d\n", scalar(@small), $self->id if @small > 0;

slic3r.pl

@@ -213,6 +213,9 @@ $j
     --layer-gcode       Load layer-change G-code from the supplied file (default: nothing).
     --extra-perimeters  Add more perimeters when needed (default: yes)
     --randomize-start   Randomize starting point across layers (default: yes)
+    --solid-infill-below-area
+                        Force solid infill when a region has a smaller area than this threshold
+                        (mm^2, default: $config->{solid_infill_below_area})
   
    Support material options:
     --support-material  Generate support material for overhangs