[Feature] Introduced experimental option to fully disable solid infill against walls when ensure vertical thickness is turned off (#3235)

* ENH: Introduced experimental option to fully disable wall solid infill when ensure vertical thickness is turned off.

* Merge branch 'main' into pr-reduce-wall-solid-infill

* Merge remote-tracking branch 'upstream/main' into pr-reduce-wall-solid-infill

* Merge branch 'pr-reduce-wall-solid-infill' of https://github.com/igiannakas/OrcaSlicer into pr-reduce-wall-solid-infill

* Merge branch 'SoftFever:main' into pr-reduce-wall-solid-infill

* Merge branch 'SoftFever:main' into pr-reduce-wall-solid-infill

* Fixed bridges too short when ensure vertical thickness is off

* Merge branch 'main' into pr-reduce-wall-solid-infill

* Fixed if statement typo

* Merge remote-tracking branch 'upstream/main' into pr-reduce-wall-solid-infill

* Updated code comments and tweaked overlap parameter to generate top solid infill.

* Parameter tweaks and caption adjustment

* Code comment update

* Merge branch 'SoftFever:main' into pr-reduce-wall-solid-infill

* Merge branch 'SoftFever:main' into pr-reduce-wall-solid-infill

* Merge branch 'SoftFever:main' into pr-reduce-wall-solid-infill

* Merge branch 'main' into pr-reduce-wall-solid-infill

* Merge branch 'main' into pr-reduce-wall-solid-infill

* Merge branch 'SoftFever:main' into pr-reduce-wall-solid-infill

src/libslic3r/Preset.cpp

@@ -768,7 +768,7 @@ bool Preset::has_cali_lines(PresetBundle* preset_bundle)
 static std::vector<std::string> s_Preset_print_options {
     "layer_height", "initial_layer_print_height", "wall_loops", "alternate_extra_wall", "slice_closing_radius", "spiral_mode", "spiral_mode_smooth", "spiral_mode_max_xy_smoothing", "slicing_mode",
     "top_shell_layers", "top_shell_thickness", "bottom_shell_layers", "bottom_shell_thickness",
-    "extra_perimeters_on_overhangs", "ensure_vertical_shell_thickness", "reduce_crossing_wall", "detect_thin_wall", "detect_overhang_wall", "overhang_reverse", "overhang_reverse_threshold","overhang_reverse_internal_only",
+    "extra_perimeters_on_overhangs", "ensure_vertical_shell_thickness","reduce_wall_solid_infill", "reduce_crossing_wall", "detect_thin_wall", "detect_overhang_wall", "overhang_reverse", "overhang_reverse_threshold","overhang_reverse_internal_only",
     "seam_position", "staggered_inner_seams", "wall_sequence", "is_infill_first", "sparse_infill_density", "sparse_infill_pattern", "top_surface_pattern", "bottom_surface_pattern",
     "infill_direction",
     "minimum_sparse_infill_area", "reduce_infill_retraction","internal_solid_infill_pattern",

src/libslic3r/PrintConfig.cpp

@@ -1297,6 +1297,16 @@ void PrintConfigDef::init_fff_params()
         "(top+bottom solid layers)");
     def->mode = comAdvanced;
     def->set_default_value(new ConfigOptionBool(true));
+    
+    def = this->add("reduce_wall_solid_infill", coBool);
+    def->label = L("Further reduce solid infill on walls (experimental)");
+    def->category = L("Strength");
+    def->tooltip = L("Further reduces any solid infill applied to walls. As there will be very limited infill supporting"
+                     " solid surfaces, make sure that you are using adequate number of walls to support the part on sloping surfaces.\n\n"
+                     "For heavily sloped surfaces this option is not suitable as it will generate too thin of a top layer "
+                     "and should be disabled.");
+    def->mode = comAdvanced;
+    def->set_default_value(new ConfigOptionBool(false));
 
     auto def_top_fill_pattern = def = this->add("top_surface_pattern", coEnum);
     def->label = L("Top surface pattern");

src/libslic3r/PrintConfig.hpp

@@ -824,6 +824,7 @@ PRINT_CONFIG_CLASS_DEFINE(
     ((ConfigOptionFloat,                bridge_speed))
     ((ConfigOptionFloatOrPercent,       internal_bridge_speed))
     ((ConfigOptionBool,                 ensure_vertical_shell_thickness))
+    ((ConfigOptionBool,                 reduce_wall_solid_infill))
     ((ConfigOptionEnum<InfillPattern>,  top_surface_pattern))
     ((ConfigOptionEnum<InfillPattern>,  bottom_surface_pattern))
     ((ConfigOptionEnum<InfillPattern>, internal_solid_infill_pattern))

src/libslic3r/PrintObject.cpp

@@ -449,17 +449,6 @@ void PrintObject::prepare_infill()
     } // for each region
 #endif /* SLIC3R_DEBUG_SLICE_PROCESSING */
 
-    // this will detect bridges and reverse bridges
-    // and rearrange top/bottom/internal surfaces
-    // It produces enlarged overlapping bridging areas.
-    //
-    // 1) stBottomBridge / stBottom infill is grown by 3mm and clipped by the total infill area. Bridges are detected. The areas may overlap.
-    // 2) stTop is grown by 3mm and clipped by the grown bottom areas. The areas may overlap.
-    // 3) Clip the internal surfaces by the grown top/bottom surfaces.
-    // 4) Merge surfaces with the same style. This will mostly get rid of the overlaps.
-    //FIXME This does not likely merge surfaces, which are supported by a material with different colors, but same properties.
-    this->process_external_surfaces();
-    m_print->throw_if_canceled();
 
     // Debugging output.
 #ifdef SLIC3R_DEBUG_SLICE_PROCESSING
@@ -478,9 +467,23 @@ void PrintObject::prepare_infill()
     // and to add a configurable number of solid layers above the BOTTOM / BOTTOMBRIDGE surfaces
     // to close these surfaces reliably.
     //FIXME Vojtech: Is this a good place to add supporting infills below sloping perimeters?
+    // Orca: Brought this function call before the process_external_surfaces, to allow bridges over holes to expand more than
+    // one perimeter. Example of this is the bridge over the benchy lettering.
     this->discover_horizontal_shells();
     m_print->throw_if_canceled();
 
+    // this will detect bridges and reverse bridges
+    // and rearrange top/bottom/internal surfaces
+    // It produces enlarged overlapping bridging areas.
+    //
+    // 1) stBottomBridge / stBottom infill is grown by 3mm and clipped by the total infill area. Bridges are detected. The areas may overlap.
+    // 2) stTop is grown by 3mm and clipped by the grown bottom areas. The areas may overlap.
+    // 3) Clip the internal surfaces by the grown top/bottom surfaces.
+    // 4) Merge surfaces with the same style. This will mostly get rid of the overlaps.
+    //FIXME This does not likely merge surfaces, which are supported by a material with different colors, but same properties.
+    this->process_external_surfaces();
+    m_print->throw_if_canceled();
+
 #ifdef SLIC3R_DEBUG_SLICE_PROCESSING
     for (size_t region_id = 0; region_id < this->num_printing_regions(); ++ region_id) {
         for (const Layer *layer : m_layers) {
@@ -3224,7 +3227,10 @@ void PrintObject::discover_horizontal_shells()
                         // No internal solid needed on this layer. In order to decide whether to continue
                         // searching on the next neighbor (thus enforcing the configured number of solid
                         // layers, use different strategies according to configured infill density:
-                        if (region_config.sparse_infill_density.value == 0) {
+                        
+                        // Orca: Also use the same strategy if the user has selected to further reduce
+                        // the amount of solid infill on walls.
+                        if (region_config.sparse_infill_density.value == 0 || region_config.reduce_wall_solid_infill) {
                             // If user expects the object to be void (for example a hollow sloping vase),
                             // don't continue the search. In this case, we only generate the external solid
                             // shell if the object would otherwise show a hole (gap between perimeters of
@@ -3237,12 +3243,19 @@ void PrintObject::discover_horizontal_shells()
                         }
                     }
 
-                    if (region_config.sparse_infill_density.value == 0) {
+                    if (region_config.sparse_infill_density.value == 0 || region_config.reduce_wall_solid_infill) {
                         // if we're printing a hollow object we discard any solid shell thinner
                         // than a perimeter width, since it's probably just crossing a sloping wall
                         // and it's not wanted in a hollow print even if it would make sense when
                         // obeying the solid shell count option strictly (DWIM!)
-                        float margin = float(neighbor_layerm->flow(frExternalPerimeter).scaled_width());
+                        
+                        // Orca: Also use the same strategy if the user has selected to reduce
+                        // the amount of solid infill on walls. However reduce the margin to 20% overhang
+                        // as we want to generate infill on sloped vertical surfaces but still keep a small amount of
+                        // filtering. This is an arbitrary value to make this option safe
+                        // by ensuring that top surfaces, especially slanted ones dont go **completely** unsupported
+                        // especially when using single perimeter top layers.
+                        float margin = region_config.reduce_wall_solid_infill? float(neighbor_layerm->flow(frExternalPerimeter).scaled_width()) * 0.2f : float(neighbor_layerm->flow(frExternalPerimeter).scaled_width());
                         Polygons too_narrow = diff(
                             new_internal_solid,
                             opening(new_internal_solid, margin, margin + ClipperSafetyOffset, jtMiter, 5));

src/slic3r/GUI/ConfigManipulation.cpp

@@ -510,6 +510,14 @@ void ConfigManipulation::toggle_print_fff_options(DynamicPrintConfig *config, co
         apply(config, &new_conf);
     }
     
+    bool have_ensure_vertical_thickness = config->opt_bool("ensure_vertical_shell_thickness");
+    if(have_ensure_vertical_thickness) {
+        DynamicPrintConfig new_conf = *config;
+        new_conf.set_key_value("reduce_wall_solid_infill", new ConfigOptionBool(false));
+        apply(config, &new_conf);
+    }
+    toggle_line("reduce_wall_solid_infill",!have_ensure_vertical_thickness);
+    
     bool have_perimeters = config->opt_int("wall_loops") > 0;
     for (auto el : { "extra_perimeters_on_overhangs", "ensure_vertical_shell_thickness", "detect_thin_wall", "detect_overhang_wall",
         "seam_position", "staggered_inner_seams", "wall_sequence", "outer_wall_line_width",

src/slic3r/GUI/Tab.cpp

@@ -2019,6 +2019,7 @@ void TabPrint::build()
         optgroup->append_single_option_line("infill_combination");
         optgroup->append_single_option_line("detect_narrow_internal_solid_infill");
         optgroup->append_single_option_line("ensure_vertical_shell_thickness");
+        optgroup->append_single_option_line("reduce_wall_solid_infill");
 
     page = add_options_page(L("Speed"), "empty");
         optgroup = page->new_optgroup(L("Initial layer speed"), L"param_speed_first", 15);