New bridge flow rate multiplier option. #85

README.markdown

@@ -126,6 +126,7 @@ The author is Alessandro Ranellucci (me).
         --extrusion-width-ratio
                             Calculate the extrusion width as the layer height multiplied by
                             this value (> 0, default: calculated automatically)
+        --bridge-flow-ratio Multiplier for extrusion when bridging (> 0, default: 1)
       
       Print options:
         --perimeters        Number of perimeters/horizontal skins (range: 1+, 

lib/Slic3r.pm

@@ -61,6 +61,7 @@ our $layer_height           = 0.4;
 our $first_layer_height_ratio = 1;
 our $infill_every_layers    = 1;
 our $extrusion_width_ratio  = 0;
+our $bridge_flow_ratio      = 1;
 our $flow_speed_ratio       = 1;
 our $flow_width;
 

lib/Slic3r/Config.pm

@@ -115,6 +115,11 @@ our $Options = {
         cli     => 'extrusion-width-ratio=f',
         type    => 'f',
     },
+    'bridge_flow_ratio' => {
+        label   => 'Bridge flow ratio',
+        cli     => 'bridge-flow-ratio=f',
+        type    => 'f',
+    },
     'first_layer_height_ratio' => {
         label   => 'First layer height ratio',
         cli     => 'first-layer-height-ratio=f',

lib/Slic3r/Fill.pm

@@ -88,14 +88,19 @@ sub make_fill {
         my $filler      = $Slic3r::fill_pattern;
         my $density     = $Slic3r::fill_density;
         my $flow_width  = $Slic3r::flow_width;
+        my $flow_ratio  = 1;
         my $is_bridge = $layer->id > 0 && $surface->surface_type eq 'bottom';
         my $is_solid = $surface->surface_type =~ /^(top|bottom)$/;
         
         # force 100% density and rectilinear fill for external surfaces
         if ($surface->surface_type ne 'internal') {
             $density = 1;
-            $filler = $is_bridge ? 'rectilinear' : $Slic3r::solid_fill_pattern;
-            $flow_width = $Slic3r::nozzle_diameter if $is_bridge;
+            $filler = $Slic3r::solid_fill_pattern;
+            if ($is_bridge) {
+                $filler = 'rectilinear';
+                $flow_width = sqrt($Slic3r::bridge_flow_ratio * ($Slic3r::nozzle_diameter**2));
+                $flow_ratio = $Slic3r::bridge_flow_ratio;
+            }
         } else {
             next SURFACE unless $density > 0;
         }
@@ -114,7 +119,7 @@ sub make_fill {
                     [ @$_ ],
                     role => ($is_bridge ? 'bridge' : $is_solid ? 'solid-fill' : 'fill'),
                     depth_layers => $surface->depth_layers,
-                    flow_ratio   => $params->{flow_ratio},
+                    flow_ratio   => $flow_ratio * ($params->{flow_ratio} || 1),
                 ), @paths,
             ],
         );

lib/Slic3r/GUI/SkeinPanel.pm

@@ -57,7 +57,7 @@ sub new {
         },
         extrusion => {
             title => 'Extrusion',
-            options => [qw(extrusion_width_ratio)],
+            options => [qw(extrusion_width_ratio bridge_flow_ratio)],
         },
     );
     $self->{panels} = \%panels;

slic3r.pl

@@ -132,6 +132,7 @@ Usage: slic3r.pl [ OPTIONS ] file.stl
     --extrusion-width-ratio
                         Calculate the extrusion width as the layer height multiplied by
                         this value (> 0, default: calculated automatically)
+    --bridge-flow-ratio Multiplier for extrusion when bridging (> 0, default: $Slic3r::bridge_flow_ratio)
   
   Print options:
     --perimeters        Number of perimeters/horizontal skins (range: 1+,