add bridge_overlap #131

src/libslic3r/Fill/Fill.cpp

@@ -332,6 +332,11 @@ void make_fill(LayerRegion &layerm, ExtrusionEntityCollection &out)
         }
         params.flow = &flow;
 
+        //apply bridge_overlap if needed
+        if (is_bridge && density > 99 && layerm.region()->config().bridge_overlap.get_abs_value(1) != 1) {
+            params.density *= layerm.region()->config().bridge_overlap.get_abs_value(1);
+        }
+
         f->fill_surface_extrusion(&surface, params, out.entities);
     }
 

src/libslic3r/PrintConfig.cpp

@@ -258,6 +258,15 @@ void PrintConfigDef::init_fff_params()
     def->mode = comAdvanced;
     def->set_default_value(new ConfigOptionFloatOrPercent(100, true));
 
+    def = this->add("bridge_overlap", coFloatOrPercent);
+    def->label = L("Bridge overlap");
+    def->full_label = L("Bridge overlap");
+    def->category = OptionCategory::width;
+    def->tooltip = L("Amount of overlap between lines of the bridge. If your bridge flow ratio is low, it may be useful to increaase this setting to let lines touch each other. Default to 100%. A value of 200% will create two times more lines.");
+    def->min = 0;
+    def->mode = comAdvanced;
+    def->set_default_value(new ConfigOptionFloatOrPercent(105, true));
+
     def = this->add("bridge_speed", coFloat);
     def->label = L("Bridges");
     def->full_label = L("Bridge speed");

src/libslic3r/PrintConfig.hpp

@@ -603,9 +603,10 @@ public:
     ConfigOptionInt                 bottom_solid_layers;
     ConfigOptionFloatOrPercent      bridge_flow_ratio;
     ConfigOptionFloatOrPercent      over_bridge_flow_ratio;
+    ConfigOptionFloatOrPercent      bridge_overlap;
     ConfigOptionEnum<InfillPattern> bottom_fill_pattern;
     ConfigOptionFloatOrPercent      bridged_infill_margin;
-    ConfigOptionFloat               bridge_speed;
+    ConfigOptionFloat               bridge_speed; 
     ConfigOptionFloat               curve_smoothing_precision;
     ConfigOptionFloat               curve_smoothing_cutoff_dist;
     ConfigOptionFloat               curve_smoothing_angle_convex;
@@ -674,6 +675,7 @@ protected:
         OPT_PTR(bottom_solid_layers);
         OPT_PTR(bridge_flow_ratio);
         OPT_PTR(over_bridge_flow_ratio);
+        OPT_PTR(bridge_overlap);
         OPT_PTR(bottom_fill_pattern);
         OPT_PTR(bridged_infill_margin);
         OPT_PTR(bridge_speed);

src/libslic3r/PrintObject.cpp

@@ -1753,6 +1753,20 @@ void PrintObject::bridge_over_infill()
             printf("Bridging " PRINTF_ZU " internal areas at layer " PRINTF_ZU "\n", to_bridge.size(), layer->id());
             #endif
             
+            //add a bit of overlap for the internal bridge, note that this can only be useful in inverted slopes and with extra_perimeters_odd_layers
+            coord_t overlap_width = 0;
+            // if extra_perimeters_odd_layers, fill the void if possible
+            if (region.config().extra_perimeters_odd_layers.value) {
+                overlap_width = layerm->flow(frPerimeter).scaled_width();
+            }
+            else
+            {
+                //half a perimeter should be enough for most of the cases.
+                overlap_width = layerm->flow(frPerimeter).scaled_width() /2;
+            }
+            if (overlap_width > 0)
+                to_bridge = offset_ex(to_bridge, overlap_width);
+
             // compute the remaning internal solid surfaces as difference
             ExPolygons not_to_bridge = diff_ex(internal_solid, to_polygons(to_bridge), true);
             to_bridge = intersection_ex(to_polygons(to_bridge), internal_solid, true);

src/slic3r/GUI/Preset.cpp

@@ -451,7 +451,9 @@ const std::vector<std::string>& Preset::print_options()
         "perimeter_extrusion_width", "external_perimeter_extrusion_width", "infill_extrusion_width", "solid_infill_extrusion_width", 
         "top_infill_extrusion_width", "support_material_extrusion_width", "infill_overlap", "bridge_flow_ratio", 
         "clip_multipart_objects",
-        "over_bridge_flow_ratio", "clip_multipart_objects", "enforce_full_fill_volume", "external_infill_margin", "bridged_infill_margin",
+        "over_bridge_flow_ratio",
+        "bridge_overlap",
+        "clip_multipart_objects", "enforce_full_fill_volume", "external_infill_margin", "bridged_infill_margin",
         "elefant_foot_compensation", "xy_size_compensation", "hole_size_compensation", 
         "hole_to_polyhole",
         "threads", "resolution",

src/slic3r/GUI/Tab.cpp

@@ -1272,6 +1272,7 @@ void TabPrint::build()
         optgroup = page->new_optgroup(_(L("Flow")));
         line = { _(L("Flow ratio")), "" };
         line.append_option(optgroup->get_option("bridge_flow_ratio"));
+        line.append_option(optgroup->get_option("bridge_overlap"));
         line.append_option(optgroup->get_option("over_bridge_flow_ratio"));
         line.append_option(optgroup->get_option("fill_top_flow_ratio"));
         optgroup->append_line(line);