avoid crossing perimeters on all layers except first layer #198

resources/ui_layout/print.ui

@@ -22,7 +22,10 @@ group:Quality (slower slicing)
 	end_line
 	setting:only_one_perimeter_top
 	setting:ensure_vertical_shell_thickness
-	setting:avoid_crossing_perimeters
+	line:Avoid crossing perimeters
+		setting:label$:avoid_crossing_perimeters
+		setting:label$not on first layer:avoid_crossing_not_first_layer
+	end_line
 	setting:thin_perimeters
 	line:Thin walls
 		setting:thin_walls

src/libslic3r/GCode.cpp

@@ -3662,7 +3662,8 @@ std::string GCode::travel_to(const Point &point, ExtrusionRole role, std::string
     if (needs_retraction
         && m_config.avoid_crossing_perimeters
         && ! m_avoid_crossing_perimeters.disable_once
-        && m_avoid_crossing_perimeters.is_init()) {
+        && m_avoid_crossing_perimeters.is_init()
+        && !(m_config.avoid_crossing_not_first_layer && this->on_first_layer())) {
         travel = m_avoid_crossing_perimeters.travel_to(*this, point);
         
         // check again whether the new travel path still needs a retraction

src/libslic3r/Print.cpp

@@ -69,6 +69,7 @@ bool Print::invalidate_state_by_config_options(const std::vector<t_config_option
     // or they are only notes not influencing the generated G-code.
     static std::unordered_set<std::string> steps_gcode = {
         "avoid_crossing_perimeters",
+		"avoid_crossing_not_first_layer",
         "bed_shape",
         "bed_temperature",
         "chamber_temperature",

src/libslic3r/PrintConfig.cpp

@@ -147,11 +147,19 @@ void PrintConfigDef::init_fff_params()
     def->label = L("Avoid crossing perimeters");
     def->category = OptionCategory::perimeter;
     def->tooltip = L("Optimize travel moves in order to minimize the crossing of perimeters. "
-                   "This is mostly useful with Bowden extruders which suffer from oozing. "
-                   "This feature slows down both the print and the G-code generation.");
+        "This is mostly useful with Bowden extruders which suffer from oozing. "
+        "This feature slows down both the print and the G-code generation.");
     def->mode = comExpert;
     def->set_default_value(new ConfigOptionBool(false));
 
+    def = this->add("avoid_crossing_not_first_layer", coBool);
+    def->label = L("Don't avoid crossing on 1st layer");
+    def->full_label = L("Don't avoid crossing on 1st layer");
+    def->category = OptionCategory::perimeter;
+    def->tooltip = L("Do not use the 'Avoid crossing perimeters' on the first layer.");
+    def->mode = comExpert;
+    def->set_default_value(new ConfigOptionBool(true));
+
     def = this->add("bed_temperature", coInts);
     def->label = L("Other layers");
     def->category = OptionCategory::filament;

src/libslic3r/PrintConfig.hpp

@@ -953,6 +953,7 @@ public:
     static double                   min_object_distance(const ConfigBase *config);
 
     ConfigOptionBool                avoid_crossing_perimeters;
+    ConfigOptionBool                avoid_crossing_not_first_layer;
     ConfigOptionPoints              bed_shape;
     ConfigOptionInts                bed_temperature;
     ConfigOptionFloat               bridge_acceleration;
@@ -1033,6 +1034,7 @@ protected:
         this->MachineEnvelopeConfig::initialize(cache, base_ptr);
         this->GCodeConfig::initialize(cache, base_ptr);
         OPT_PTR(avoid_crossing_perimeters);
+        OPT_PTR(avoid_crossing_not_first_layer);
         OPT_PTR(bed_shape);
         OPT_PTR(bed_temperature);
         OPT_PTR(bridge_acceleration);

src/slic3r/GUI/ConfigManipulation.cpp

@@ -309,6 +309,8 @@ void ConfigManipulation::toggle_print_fff_options(DynamicPrintConfig* config)
 
     toggle_field("gap_fill_min_area", config->opt_bool("gap_fill"));
 
+    toggle_field("avoid_crossing_not_first_layer", config->opt_bool("avoid_crossing_perimeters"));
+
     bool have_infill = config->option<ConfigOptionPercent>("fill_density")->value > 0;
     // infill_extruder uses the same logic as in Print::extruders()
     for (auto el : { "fill_pattern", "infill_every_layers", "infill_only_where_needed",

src/slic3r/GUI/Preset.cpp

@@ -427,6 +427,7 @@ const std::vector<std::string>& Preset::print_options()
         "extra_perimeters",
         "extra_perimeters_odd_layers",
         "only_one_perimeter_top", "ensure_vertical_shell_thickness", "avoid_crossing_perimeters", 
+        "avoid_crossing_not_first_layer",
         "thin_perimeters",
         "thin_walls", "overhangs", 
         "overhangs_width",

src/slic3r/GUI/Tab.cpp

@@ -1598,6 +1598,7 @@ void TabPrint::build()
         optgroup->append_single_option_line("only_one_perimeter_top");
         optgroup->append_single_option_line("ensure_vertical_shell_thickness");
         optgroup->append_single_option_line("avoid_crossing_perimeters");
+        optgroup->append_single_option_line("avoid_crossing_not_first_layer");
         optgroup->append_single_option_line("thin_perimeters");
         line = { _(L("Thin walls")), "" };
         line.append_option(optgroup->get_option("thin_walls"));