Support threshold overlap (#6606)

* Support threshold overlap

* Update tooltip

src/libslic3r/Preset.cpp

@@ -785,7 +785,7 @@ static std::vector<std::string> s_Preset_print_options {
     "top_surface_speed", "support_speed", "support_object_xy_distance", "support_interface_speed",
     "bridge_speed", "internal_bridge_speed", "gap_infill_speed", "travel_speed", "travel_speed_z", "initial_layer_speed",
     "outer_wall_acceleration", "initial_layer_acceleration", "top_surface_acceleration", "default_acceleration", "skirt_type", "skirt_loops", "skirt_speed","min_skirt_length", "skirt_distance", "skirt_start_angle", "skirt_height", "draft_shield",
-    "brim_width", "brim_object_gap", "brim_type", "brim_ears_max_angle", "brim_ears_detection_length", "enable_support", "support_type", "support_threshold_angle", "enforce_support_layers",
+    "brim_width", "brim_object_gap", "brim_type", "brim_ears_max_angle", "brim_ears_detection_length", "enable_support", "support_type", "support_threshold_angle", "support_threshold_overlap","enforce_support_layers",
     "raft_layers", "raft_first_layer_density", "raft_first_layer_expansion", "raft_contact_distance", "raft_expansion",
     "support_base_pattern", "support_base_pattern_spacing", "support_expansion", "support_style",
     "independent_support_layer_height",

src/libslic3r/PrintConfig.cpp

@@ -4722,11 +4722,22 @@ void PrintConfigDef::init_fff_params()
     def->category = L("Support");
     def->tooltip = L("Support will be generated for overhangs whose slope angle is below the threshold.");
     def->sidetext = L("°");
-    def->min = 1;
+    def->min = 0;
     def->max = 90;
     def->mode = comSimple;
     def->set_default_value(new ConfigOptionInt(30));
 
+    def = this->add("support_threshold_overlap", coFloatOrPercent);
+    def->label = L("Threshold overlap");
+    def->category = L("Support");
+    def->tooltip = L("If threshold angle is zero, support will be generated for overhangs whose overlap is below the threshold. The smaller this value is, the steeper the overhang that can be printed without support.");
+    def->sidetext = L("mm or %");
+    def->min = 0;
+    def->max = 100;
+    def->max_literal = 0.5;
+    def->mode = comSimple;
+    def->set_default_value(new ConfigOptionFloatOrPercent(50., true));
+
     def = this->add("tree_support_branch_angle", coFloat);
     def->label = L("Tree support branch angle");
     def->category = L("Support");

src/libslic3r/PrintConfig.hpp

@@ -820,6 +820,7 @@ PRINT_CONFIG_CLASS_DEFINE(
     ((ConfigOptionEnum<InternalBridgeFilter>,  dont_filter_internal_bridges))
     // Overhang angle threshold.
     ((ConfigOptionInt,                 support_threshold_angle))
+    ((ConfigOptionFloatOrPercent,      support_threshold_overlap))
     ((ConfigOptionFloat,               support_object_xy_distance))
     ((ConfigOptionFloat,               xy_hole_compensation))
     ((ConfigOptionFloat,               xy_contour_compensation))

src/libslic3r/PrintObject.cpp

@@ -1019,6 +1019,7 @@ bool PrintObject::invalidate_state_by_config_options(
             || opt_key == "support_expansion"
             //|| opt_key == "independent_support_layer_height" // BBS
             || opt_key == "support_threshold_angle"
+            || opt_key == "support_threshold_overlap"
             || opt_key == "raft_expansion"
             || opt_key == "raft_first_layer_density"
             || opt_key == "raft_first_layer_expansion"

src/libslic3r/Support/SupportMaterial.cpp

@@ -1517,8 +1517,8 @@ static inline ExPolygons detect_overhangs(
                 (threshold_rad > 0. ? 
                     // Overhang defined by an angle.
                     float(scale_(lower_layer.height / tan(threshold_rad))) :
-                    // Overhang defined by half the extrusion width.
-                    0.5f * fw);
+                    // Overhang defined by overlap.
+                    fw - float(scale_(object_config.support_threshold_overlap.get_abs_value(unscale_(fw)))));
             // Overhang polygons for this layer and region.
             Polygons diff_polygons;
             Polygons layerm_polygons = to_polygons(layerm->slices.surfaces);

src/libslic3r/Support/TreeSupport3D.cpp

@@ -239,7 +239,7 @@ static std::vector<std::pair<TreeSupportSettings, std::vector<size_t>>> group_me
                     for (const LayerRegion *layerm : lower_layer.regions())
                         external_perimeter_width += layerm->flow(frExternalPerimeter).scaled_width();
                     external_perimeter_width /= lower_layer.region_count();
-                    lower_layer_offset = float(0.5 * external_perimeter_width);
+                    lower_layer_offset = external_perimeter_width - float(scale_(config.support_threshold_overlap.get_abs_value(unscale_(external_perimeter_width))));
                 } else
                     lower_layer_offset = scaled<float>(lower_layer.height / tan_threshold);
                 overhangs = lower_layer_offset == 0 ?

src/slic3r/GUI/ConfigManipulation.cpp

@@ -599,6 +599,7 @@ void ConfigManipulation::toggle_print_fff_options(DynamicPrintConfig *config, co
         "support_object_xy_distance"/*, "independent_support_layer_height"*/})
         toggle_field(el, have_support_material);
     toggle_field("support_threshold_angle", have_support_material && is_auto(support_type));
+    toggle_field("support_threshold_overlap", config->opt_int("support_threshold_angle") == 0 && have_support_material && is_auto(support_type));
     //toggle_field("support_closing_radius", have_support_material && support_style == smsSnug);
 
     bool support_is_tree = config->opt_bool("enable_support") && is_tree(support_type);

src/slic3r/GUI/GUI_Factories.cpp

@@ -61,7 +61,7 @@ static SettingsFactory::Bundle FREQ_SETTINGS_BUNDLE_FFF =
     { L("Shell"), { "wall_loops", "top_shell_layers", "bottom_shell_layers"} },
     { L("Infill")               , { "sparse_infill_density", "sparse_infill_pattern" } },
     // BBS
-    { L("Support")     , { "enable_support", "support_type", "support_threshold_angle",
+    { L("Support")     , { "enable_support", "support_type", "support_threshold_angle", "support_threshold_overlap",
                                     "support_base_pattern", "support_on_build_plate_only","support_critical_regions_only",
                                     "support_remove_small_overhang",
                                     "support_base_pattern_spacing", "support_expansion"}},
@@ -88,7 +88,7 @@ std::map<std::string, std::vector<SimpleSettingData>>  SettingsFactory::OBJECT_C
 
                     }},
     { L("Support"), {{"brim_type", "",1},{"brim_width", "",2},{"brim_object_gap", "",3},
-                    {"enable_support", "",4},{"support_type", "",5},{"support_threshold_angle", "",6},{"support_on_build_plate_only", "",7},
+                    {"enable_support", "",4},{"support_type", "",5},{"support_threshold_angle", "",6}, {"support_threshold_overlap", "",6}, {"support_on_build_plate_only", "",7},
                     {"support_filament", "",8},{"support_interface_filament", "",9},{"support_expansion", "",24},{"support_style", "",25},
                     {"tree_support_brim_width", "",26}, {"tree_support_branch_angle", "",10},{"tree_support_branch_angle_organic","",10}, {"tree_support_wall_count", "",11},//tree support
                             {"support_top_z_distance", "",13},{"support_bottom_z_distance", "",12},{"support_base_pattern", "",14},{"support_base_pattern_spacing", "",15},
@@ -150,7 +150,7 @@ std::vector<SimpleSettingData> SettingsFactory::get_visible_options(const std::s
         //Quality
         "layer_height", "initial_layer_print_height", "adaptive_layer_height", "seam_position", "xy_hole_compensation", "xy_contour_compensation", "elefant_foot_compensation", "support_line_width",
         //Support
-        "enable_support", "support_type", "support_threshold_angle", "support_on_build_plate_only", "support_critical_regions_only", "enforce_support_layers",
+        "enable_support", "support_type", "support_threshold_angle", "support_threshold_overlap", "support_on_build_plate_only", "support_critical_regions_only", "enforce_support_layers",
         //tree support
         "tree_support_wall_count",
         //support

src/slic3r/GUI/Tab.cpp

@@ -2227,6 +2227,7 @@ void TabPrint::build()
         optgroup->append_single_option_line("support_type", "support#support-types");
         optgroup->append_single_option_line("support_style", "support#support-styles");
         optgroup->append_single_option_line("support_threshold_angle", "support#threshold-angle");
+        optgroup->append_single_option_line("support_threshold_overlap", "support#threshold-angle");
         optgroup->append_single_option_line("raft_first_layer_density");
         optgroup->append_single_option_line("raft_first_layer_expansion");
         optgroup->append_single_option_line("support_on_build_plate_only");