Reverse extrusion directions

src/libslic3r/GCode.cpp

@@ -2952,7 +2952,7 @@ static inline bool validate_smooth_path(const GCode::SmoothPath &smooth_path, bo
 
 static constexpr const double min_gcode_segment_length = 0.002;
 
-std::string GCodeGenerator::extrude_loop(const ExtrusionLoop &loop_src, const GCode::SmoothPathCache &smooth_path_cache, const std::string_view description, double speed)
+std::string GCodeGenerator::extrude_loop(const ExtrusionLoop &loop_src, bool reverse, const GCode::SmoothPathCache &smooth_path_cache, const std::string_view description, double speed)
 {
     // Extrude all loops CCW.
     bool is_hole = loop_src.is_clockwise();
@@ -2964,7 +2964,7 @@ std::string GCodeGenerator::extrude_loop(const ExtrusionLoop &loop_src, const GC
     // Because the G-code export has 1um resolution, don't generate segments shorter than 1.5 microns,
     // thus empty path segments will not be produced by G-code export.
     GCode::SmoothPath smooth_path = smooth_path_cache.resolve_or_fit_split_with_seam(
-        loop_src, is_hole, m_scaled_resolution, seam_point, scaled<double>(0.0015));
+        loop_src, reverse ^ is_hole, m_scaled_resolution, seam_point, scaled<double>(0.0015));
 
     // Clip the path to avoid the extruder to get exactly on the first point of the loop;
     // if polyline was shorter than the clipping distance we'd get a null polyline, so
@@ -3012,7 +3012,7 @@ std::string GCodeGenerator::extrude_skirt(
     assert(loop_src.is_counter_clockwise());
     Point seam_point = this->last_position.has_value() ? *this->last_position : Point::Zero();
     GCode::SmoothPath smooth_path = smooth_path_cache.resolve_or_fit_split_with_seam(
-        loop_src, false, m_scaled_resolution, seam_point, scaled<double>(0.0015));
+        loop_src, this->m_layer->id() % 2 == 1, m_scaled_resolution, seam_point, scaled<double>(0.0015));
 
     // Clip the path to avoid the extruder to get exactly on the first point of the loop;
     // if polyline was shorter than the clipping distance we'd get a null polyline, so
@@ -3073,9 +3073,22 @@ std::string GCodeGenerator::extrude_entity(const ExtrusionEntityReference &entit
         return this->extrude_path(*path, entity.flipped(), smooth_path_cache, description, speed);
     else if (const ExtrusionMultiPath *multipath = dynamic_cast<const ExtrusionMultiPath*>(&entity.extrusion_entity()))
         return this->extrude_multi_path(*multipath, entity.flipped(), smooth_path_cache, description, speed);
-    else if (const ExtrusionLoop *loop = dynamic_cast<const ExtrusionLoop*>(&entity.extrusion_entity()))
-        return this->extrude_loop(*loop, smooth_path_cache, description, speed);
-    else
+    else if (const ExtrusionLoop *loop = dynamic_cast<const ExtrusionLoop*>(&entity.extrusion_entity())) {
+        ExtrusionRole role = entity.extrusion_entity().role();
+        bool reverse = 
+                this->m_layer->id() % 2 == 1 &&
+                (role.is_perimeter() && this->config().reverse_perimeters_even ||
+                 role.is_infill() && this->config().reverse_infill_even);
+
+        if (this->config().reverse_overhangs) {
+            for (ExtrusionPath el: loop->paths)
+                if (el.role().is_perimeter() && el.role().is_bridge() && this->m_layer->id() % 2 == 1) {
+                    reverse = true;
+                    break;
+                }
+        }
+        return this->extrude_loop(*loop, reverse, smooth_path_cache, description, speed);
+    } else
         throw Slic3r::InvalidArgument("Invalid argument supplied to extrude()");
     return {};
 }
@@ -3106,10 +3119,11 @@ std::string GCodeGenerator::extrude_support(const ExtrusionEntityReferences &sup
             const auto   label = (role == ExtrusionRole::SupportMaterial) ? support_label : support_interface_label;
             const double speed = (role == ExtrusionRole::SupportMaterial) ? support_speed : support_interface_speed;
             const ExtrusionPath *path = dynamic_cast<const ExtrusionPath*>(&eref.extrusion_entity());
+            bool reverse = (this->m_layer->id() % 2 == 1);
             if (path)
-                gcode += this->extrude_path(*path, eref.flipped(), smooth_path_cache, label, speed);
+                gcode += this->extrude_path(*path, reverse ^ eref.flipped(), smooth_path_cache, label, speed);
             else if (const ExtrusionMultiPath *multipath = dynamic_cast<const ExtrusionMultiPath*>(&eref.extrusion_entity()); multipath)
-                gcode += this->extrude_multi_path(*multipath, eref.flipped(), smooth_path_cache, label, speed);
+                gcode += this->extrude_multi_path(*multipath, reverse ^ eref.flipped(), smooth_path_cache, label, speed);
             else {
                 const ExtrusionEntityCollection *eec = dynamic_cast<const ExtrusionEntityCollection*>(&eref.extrusion_entity());
                 assert(eec);

src/libslic3r/GCode.hpp

@@ -278,7 +278,7 @@ class GCodeGenerator {
         bool vase_mode
     );
     std::string     extrude_entity(const ExtrusionEntityReference &entity, const GCode::SmoothPathCache &smooth_path_cache, const std::string_view description, double speed = -1.);
-    std::string     extrude_loop(const ExtrusionLoop &loop, const GCode::SmoothPathCache &smooth_path_cache, const std::string_view description, double speed = -1.);
+    std::string     extrude_loop(const ExtrusionLoop &loop, bool reverse, const GCode::SmoothPathCache &smooth_path_cache, const std::string_view description, double speed = -1.);
     std::string     extrude_skirt(const ExtrusionLoop &loop_src, const ExtrusionFlow &extrusion_flow_override,
         const GCode::SmoothPathCache &smooth_path_cache, const std::string_view description, double speed);
 

src/libslic3r/Preset.cpp

@@ -473,6 +473,7 @@ static std::vector<std::string> s_Preset_print_options {
     "mmu_segmented_region_interlocking_depth", "wipe_tower_extruder", "wipe_tower_no_sparse_layers", "wipe_tower_extra_flow", "wipe_tower_extra_spacing", "compatible_printers", "compatible_printers_condition", "inherits",
     "perimeter_generator", "wall_transition_length", "wall_transition_filter_deviation", "wall_transition_angle",
     "wall_distribution_count", "min_feature_size", "min_bead_width"
+    "reverse_overhangs", "reverse_perimeters_even", "reverse_infill_even"
 };
 
 static std::vector<std::string> s_Preset_filament_options {

src/libslic3r/PrintConfig.cpp

@@ -2494,6 +2494,7 @@ void PrintConfigDef::init_fff_params()
     def->mode = comAdvanced;
     def->set_default_value(new ConfigOptionBool(false));
 
+    def->sidetext = L("%");
 #if 0
     def = this->add("seam_preferred_direction", coFloat);
 //    def->gui_type = ConfigOptionDef::GUIType::slider;
@@ -3535,6 +3536,27 @@ void PrintConfigDef::init_fff_params()
     def->min = 0;
     def->set_default_value(new ConfigOptionFloatOrPercent(85, true));
 
+    def = this->add("reverse_overhangs", coBool);
+    def->label = L("Reverse external perimeters with overhang direction every layer");
+    def->category = L("Advanced");
+    def->tooltip = L("Extrude each layer overhang perimeters in opposite direction, improving quality.");
+    def->mode = comAdvanced;
+    def->set_default_value(new ConfigOptionBool(false));
+
+    def = this->add("reverse_perimeters_even", coBool);
+    def->label = L("Reverse perimeters directions on even layers");
+    def->category = L("Advanced");
+    def->tooltip = L("Extrude each layer perimeters in opposite direction, reduce internal stress and warping.");
+    def->mode = comAdvanced;
+    def->set_default_value(new ConfigOptionBool(false));
+
+    def = this->add("reverse_infill_even", coBool);
+    def->label = L("Reverse infill direction every layer");
+    def->category = L("Advanced");
+    def->tooltip = L("Extrude each layer infill in opposite direction, reduce internal stress and warping.");
+    def->mode = comAdvanced;
+    def->set_default_value(new ConfigOptionBool(false));
+
     // Declare retract values for filament profile, overriding the printer's extruder profile.
     for (const char *opt_key : {
         // floats

src/libslic3r/PrintConfig.hpp

@@ -649,6 +649,10 @@ PRINT_CONFIG_CLASS_DEFINE(
     ((ConfigOptionFloat,                perimeter_speed))
     // Total number of perimeters.
     ((ConfigOptionInt,                  perimeters))
+    //Perimeters reverse
+    ((ConfigOptionBool,                 reverse_overhangs))
+    ((ConfigOptionBool,                 reverse_perimeters_even))
+    ((ConfigOptionBool,                 reverse_infill_even))
     ((ConfigOptionFloatOrPercent,       small_perimeter_speed))
     ((ConfigOptionFloat,                solid_infill_below_area))
     ((ConfigOptionInt,                  solid_infill_extruder))

src/libslic3r/PrintObject.cpp

@@ -715,7 +715,9 @@ bool PrintObject::invalidate_state_by_config_options(
             || opt_key == "perimeter_extrusion_width"
             || opt_key == "infill_overlap"
             || opt_key == "external_perimeters_first"
-            || opt_key == "arc_fitting") {
+            || opt_key == "arc_fitting"
+            || opt_key == "reverse_overhangs"
+            || opt_key == "reverse_perimeters_even") {
             steps.emplace_back(posPerimeters);
         } else if (
                opt_key == "gap_fill_enabled"

src/slic3r/GUI/Tab.cpp

@@ -1691,6 +1691,11 @@ void TabPrint::build()
         optgroup->append_single_option_line("xy_size_compensation");
         optgroup->append_single_option_line("elefant_foot_compensation", "elephant-foot-compensation_114487");
 
+        optgroup = page->new_optgroup(L("Extrusion direction reverse"));
+        optgroup->append_single_option_line("reverse_overhangs");
+        optgroup->append_single_option_line("reverse_perimeters_even");
+        optgroup->append_single_option_line("reverse_infill_even");
+
         optgroup = page->new_optgroup(L("Arachne perimeter generator"));
         optgroup->append_single_option_line("wall_transition_angle");
         optgroup->append_single_option_line("wall_transition_filter_deviation");