Implement new 'fuzzy skin' type: displacement mapping

Add new fuzzy skin type: displacement map. This feature uses an 8-bit grayscale PNG to displace the object's surface based on pixel values.

The displacement map is applied by mapping the surface points of the 3D model to the corresponding points on the 2D displacement map.

The UV mapping in this implementation is simple: it treats the object's as a cube.
It determines which face of the cube the current line is on based on the direction of the bump (which is just perpendicular to the line).
The U coordinate is calculated based on the x, y coordinates of the point on the line relative to the bounding box and the determined face.
The V coordinate is based on the current layer's height.
This method works surpsingly well for many objects but may fail for more complex shapes like ramps.

This feature is based on work by the PrusaSlicer community member Poikilos, who initially implemented displacement and cube mapping.

src/libslic3r/LayerRegion.cpp

@@ -92,6 +92,7 @@ void LayerRegion::make_perimeters(const SurfaceCollection &slices, const LayerRe
         &region_config,
         &this->layer()->object()->config(),
         &print_config,
+        this->layer()->object(),
         spiral_mode,
 
         // output:

src/libslic3r/PerimeterGenerator.hpp

@@ -20,6 +20,7 @@ struct FuzzySkinConfig
     double        noise_scale;
     int           noise_octaves;
     double        noise_persistence;
+    std::string   displacement_map_path;
 
     bool operator==(const FuzzySkinConfig& r) const
     {
@@ -30,7 +31,8 @@ struct FuzzySkinConfig
             && noise_type == r.noise_type
             && noise_scale == r.noise_scale
             && noise_octaves == r.noise_octaves
-            && noise_persistence == r.noise_persistence;
+            && noise_persistence == r.noise_persistence
+            && displacement_map_path == r.displacement_map_path;
     }
 
     bool operator!=(const FuzzySkinConfig& r) const { return !(*this == r); }
@@ -50,6 +52,7 @@ template<> struct hash<Slic3r::FuzzySkinConfig>
         boost::hash_combine(seed, std::hash<double>{}(c.noise_scale));
         boost::hash_combine(seed, std::hash<int>{}(c.noise_octaves));
         boost::hash_combine(seed, std::hash<double>{}(c.noise_persistence));
+        boost::hash_combine(seed, std::hash<std::string>{}(c.displacement_map_path));
         return seed;
     }
 };
@@ -74,6 +77,7 @@ class PerimeterGenerator {
     const PrintRegionConfig     *config;
     const PrintObjectConfig     *object_config;
     const PrintConfig           *print_config;
+    const PrintObject           *print_object;
     // Outputs:
     ExtrusionEntityCollection   *loops;
     ExtrusionEntityCollection   *gap_fill;
@@ -104,6 +108,7 @@ class PerimeterGenerator {
         const PrintRegionConfig*    config,
         const PrintObjectConfig*    object_config,
         const PrintConfig*          print_config,
+        const PrintObject*          print_object,
         const bool                  spiral_mode,
         // Output:
         // Loops with the external thin walls
@@ -118,6 +123,7 @@ class PerimeterGenerator {
             slice_z(slice_z), layer_id(-1), perimeter_flow(flow), ext_perimeter_flow(flow),
             overhang_flow(flow), solid_infill_flow(flow),
             config(config), object_config(object_config), print_config(print_config),
+            print_object(print_object),
             m_spiral_vase(spiral_mode),
             m_scaled_resolution(scaled<double>(print_config->resolution.value > EPSILON ? print_config->resolution.value : EPSILON)),
             loops(loops), gap_fill(gap_fill), fill_surfaces(fill_surfaces), fill_no_overlap(fill_no_overlap),
@@ -136,6 +142,8 @@ class PerimeterGenerator {
     double      smaller_width_ext_mm3_per_mm()   const { return m_ext_mm3_per_mm_smaller_width; }
     Polygons    lower_slices_polygons() const { return m_lower_slices_polygons; }
 
+    const PrintObject* object() const { return print_object; }
+
 private:
     std::vector<Polygons>     generate_lower_polygons_series(float width);
     void split_top_surfaces(const ExPolygons &orig_polygons, ExPolygons &top_fills, ExPolygons &non_top_polygons, ExPolygons &fill_clip) const;

src/libslic3r/Preset.cpp

@@ -789,7 +789,7 @@ static std::vector<std::string> s_Preset_print_options {
     "minimum_sparse_infill_area", "reduce_infill_retraction","internal_solid_infill_pattern","gap_fill_target",
     "ironing_type", "ironing_pattern", "ironing_flow", "ironing_speed", "ironing_spacing", "ironing_angle", "ironing_inset",
     "max_travel_detour_distance",
-    "fuzzy_skin", "fuzzy_skin_thickness", "fuzzy_skin_point_distance", "fuzzy_skin_first_layer", "fuzzy_skin_noise_type", "fuzzy_skin_scale", "fuzzy_skin_octaves", "fuzzy_skin_persistence",
+    "fuzzy_skin", "fuzzy_skin_thickness", "fuzzy_skin_point_distance", "fuzzy_skin_first_layer", "fuzzy_skin_noise_type", "fuzzy_skin_scale", "fuzzy_skin_octaves", "fuzzy_skin_persistence", "fuzzy_skin_displacement_map",
     "max_volumetric_extrusion_rate_slope", "max_volumetric_extrusion_rate_slope_segment_length","extrusion_rate_smoothing_external_perimeter_only",
     "inner_wall_speed", "outer_wall_speed", "sparse_infill_speed", "internal_solid_infill_speed",
     "top_surface_speed", "support_speed", "support_object_xy_distance", "support_interface_speed",

src/libslic3r/PrintConfig.cpp

@@ -128,7 +128,8 @@ static t_config_enum_values s_keys_map_NoiseType {
     { "perlin",         int(NoiseType::Perlin) },
     { "billow",         int(NoiseType::Billow) },
     { "ridgedmulti",    int(NoiseType::RidgedMulti) },
-    { "voronoi",        int(NoiseType::Voronoi) }
+    { "voronoi",        int(NoiseType::Voronoi) },
+    { "displacementmap",int(NoiseType::DisplacementMap) }
 };
 CONFIG_OPTION_ENUM_DEFINE_STATIC_MAPS(NoiseType)
 
@@ -2649,18 +2650,21 @@ void PrintConfigDef::init_fff_params()
                      "Perlin: Perlin noise, which gives a more consistent texture.\n"
                      "Billow: Similar to perlin noise, but clumpier.\n"
                      "Ridged Multifractal: Ridged noise with sharp, jagged features. Creates marble-like textures.\n"
-                     "Voronoi: Divides the surface into voronoi cells, and displaces each one by a random amount. Creates a patchwork texture.");
+                     "Voronoi: Divides the surface into voronoi cells, and displaces each one by a random amount. Creates a patchwork texture.\n"
+                     "Displacement Map: Deforms the perimeter with an image-based displacement map.");
     def->enum_keys_map = &ConfigOptionEnum<NoiseType>::get_enum_values();
     def->enum_values.push_back("classic");
     def->enum_values.push_back("perlin");
     def->enum_values.push_back("billow");
     def->enum_values.push_back("ridgedmulti");
     def->enum_values.push_back("voronoi");
+    def->enum_values.push_back("displacementmap");
     def->enum_labels.push_back(L("Classic"));
     def->enum_labels.push_back(L("Perlin"));
     def->enum_labels.push_back(L("Billow"));
     def->enum_labels.push_back(L("Ridged Multifractal"));
     def->enum_labels.push_back(L("Voronoi"));
+    def->enum_labels.push_back(L("Displacement Map"));
     def->mode = comSimple;
     def->set_default_value(new ConfigOptionEnum<NoiseType>(NoiseType::Classic));
 
@@ -2692,6 +2696,13 @@ void PrintConfigDef::init_fff_params()
     def->mode = comAdvanced;
     def->set_default_value(new ConfigOptionFloat(0.5));
 
+    def = this->add("fuzzy_skin_displacement_map", coString);
+    def->label = L("Fuzzy skin displacement map filepath");
+    def->tooltip = L("Specifies the path to an 8-bit grayscale PNG file used for displacement mapping.");
+    def->category = L("Others");
+    def->mode = comSimple;
+    def->set_default_value(new ConfigOptionString());
+
     def = this->add("filter_out_gap_fill", coFloat);
     def->label = L("Filter out tiny gaps");
     def->category = L("Layers and Perimeters");

src/libslic3r/PrintConfig.hpp

@@ -47,6 +47,7 @@ enum class NoiseType {
     Billow,
     RidgedMulti,
     Voronoi,
+    DisplacementMap,
 };
 
 enum PrintHostType {
@@ -930,6 +931,7 @@ PRINT_CONFIG_CLASS_DEFINE(
     ((ConfigOptionFloat,                fuzzy_skin_scale))
     ((ConfigOptionInt,                  fuzzy_skin_octaves))
     ((ConfigOptionFloat,                fuzzy_skin_persistence))
+    ((ConfigOptionString,               fuzzy_skin_displacement_map))
     ((ConfigOptionFloat,                gap_infill_speed))
     ((ConfigOptionInt,                  sparse_infill_filament))
     ((ConfigOptionFloatOrPercent,       sparse_infill_line_width))

src/libslic3r/PrintObject.cpp

@@ -1121,6 +1121,7 @@ bool PrintObject::invalidate_state_by_config_options(
             || opt_key == "fuzzy_skin_scale"
             || opt_key == "fuzzy_skin_octaves"
             || opt_key == "fuzzy_skin_persistence"
+            || opt_key == "fuzzy_skin_displacement_map"
             || opt_key == "detect_overhang_wall"
             || opt_key == "overhang_reverse"
             || opt_key == "overhang_reverse_internal_only"

src/slic3r/GUI/ConfigManipulation.cpp

@@ -712,9 +712,10 @@ void ConfigManipulation::toggle_print_fff_options(DynamicPrintConfig *config, co
         toggle_line(el, has_fuzzy_skin);
 
     NoiseType fuzzy_skin_noise_type = config->opt_enum<NoiseType>("fuzzy_skin_noise_type");
-    toggle_line("fuzzy_skin_scale", has_fuzzy_skin && fuzzy_skin_noise_type != NoiseType::Classic);
-    toggle_line("fuzzy_skin_octaves", has_fuzzy_skin && fuzzy_skin_noise_type != NoiseType::Classic && fuzzy_skin_noise_type != NoiseType::Voronoi);
+    toggle_line("fuzzy_skin_scale", has_fuzzy_skin && (fuzzy_skin_noise_type != NoiseType::Classic && fuzzy_skin_noise_type != NoiseType::DisplacementMap));
+    toggle_line("fuzzy_skin_octaves", has_fuzzy_skin && fuzzy_skin_noise_type != NoiseType::Classic && fuzzy_skin_noise_type != NoiseType::Voronoi && fuzzy_skin_noise_type != NoiseType::DisplacementMap);
     toggle_line("fuzzy_skin_persistence", has_fuzzy_skin && (fuzzy_skin_noise_type == NoiseType::Perlin || fuzzy_skin_noise_type == NoiseType::Billow));
+    toggle_line("fuzzy_skin_displacement", has_fuzzy_skin && fuzzy_skin_noise_type == NoiseType::DisplacementMap);
 
     bool have_arachne = config->opt_enum<PerimeterGeneratorType>("wall_generator") == PerimeterGeneratorType::Arachne;
     for (auto el : { "wall_transition_length", "wall_transition_filter_deviation", "wall_transition_angle",

src/slic3r/GUI/Tab.cpp

@@ -2353,6 +2353,7 @@ page = add_options_page(L("Others"), "custom-gcode_other"); // ORCA: icon only v
 
         optgroup->append_single_option_line("fuzzy_skin");
         optgroup->append_single_option_line("fuzzy_skin_noise_type");
+        optgroup->append_single_option_line("fuzzy_skin_displacement_map");
         optgroup->append_single_option_line("fuzzy_skin_point_distance");
         optgroup->append_single_option_line("fuzzy_skin_thickness");
         optgroup->append_single_option_line("fuzzy_skin_scale");