#4 perimeter overlaps : total control over perimeter width vs spacing.

- add a spacing_ratio in flow, but it's only sed for two spacing in perimeter_generator, not sure about the usefulness of it.
 - external_perimeter_overlap now use the spacing_ratio to compute
 - add perimeter_overlap, using the spacing_ratio to compute
 - add perimeter_bonding, that shrink the external-internal spacing, without growing the infill polygons.

resources/ui_layout/print.ui

@@ -54,16 +54,18 @@ group:Advanced
 		setting:seam_position
 		setting:seam_travel
 	end_line
-	line:External Perimeter
-		setting:external_perimeters_first
-		setting:external_perimeters_vase
-		setting:external_perimeters_nothole
-		setting:external_perimeters_hole
-	end_line
 	line:Looping perimeter
 		setting:perimeter_loop
 		setting:perimeter_loop_seam
 	end_line
+group: External perimeter first
+	setting:label$Activate:external_perimeters_first
+	line:Apply on
+		setting:external_perimeters_nothole
+		setting:external_perimeters_hole
+	end_line
+	setting:external_perimeters_vase
+	setting:perimeter_bonding
 
 page:Slicing:layers
 group:Layer height
@@ -230,9 +232,12 @@ group:Extrusion width
 	setting:top_infill_extrusion_width
 	setting:support_material_extrusion_width
 group:Overlap
+	line:Perimeter overlap
+		setting:label$External:external_perimeter_overlap
+		setting:label$Inner:perimeter_overlap
+	end_line
 	setting:infill_overlap
 	setting:bridge_overlap
-	setting:external_perimeter_overlap
 group:Flow
 	line:Flow ratio
 		setting:bridge_flow_ratio

src/libslic3r/Flow.cpp

@@ -172,7 +172,7 @@ float Flow::spacing() const
     float min_flow_spacing = this->width - this->height * (1. - 0.25 * PI);
     float res = this->width - PERIMETER_LINE_OVERLAP_FACTOR * (this->width - min_flow_spacing);
 #else
-    float res = float(this->bridge ? (this->width + BRIDGE_EXTRA_SPACING_MULT * nozzle_diameter) : (this->width - this->height * (1. - 0.25 * PI)));
+    float res = float(this->bridge ? (this->width + BRIDGE_EXTRA_SPACING_MULT * nozzle_diameter) : (this->width - this->height * (1. - 0.25 * PI) * spacing_ratio));
 #endif
 //    assert(res > 0.f);
 	if (res <= 0.f)

src/libslic3r/Flow.hpp

@@ -65,6 +65,8 @@ public:
     float nozzle_diameter;
     // Is it a bridge?
     bool  bridge;
+    // % of spacing taken into account 1=>all/default, 0=> width=spacing
+    float spacing_ratio = 1;
     
     Flow(float _w, float _h, float _nd, bool _bridge = false) :
         width(_w), height(_h), nozzle_diameter(_nd), bridge(_bridge) {}

src/libslic3r/PerimeterGenerator.cpp

@@ -37,6 +37,10 @@ namespace Slic3r {
 
 void PerimeterGenerator::process()
 {
+    //set spacing
+    this->perimeter_flow.spacing_ratio = this->object_config->perimeter_overlap.get_abs_value(1);
+    this->ext_perimeter_flow.spacing_ratio = this->object_config->external_perimeter_overlap.get_abs_value(1);
+
     // other perimeters
     this->_mm3_per_mm               = this->perimeter_flow.mm3_per_mm();
     coord_t perimeter_width         = this->perimeter_flow.scaled_width();
@@ -50,22 +54,30 @@ void PerimeterGenerator::process()
     coord_t ext_perimeter_spacing   = this->ext_perimeter_flow.scaled_spacing();
     //spacing between external perimeter and the second
     coord_t ext_perimeter_spacing2  = this->ext_perimeter_flow.scaled_spacing(this->perimeter_flow);
-    //external_perimeter_overlap effect: change distance between the extrenal periemter and the other ones.
+
-    if (this->config->external_perimeter_overlap.get_abs_value(1) != 1) {
-        //choose between the normal spacing and "don't touch it".
-        ext_perimeter_spacing2 =
-            ext_perimeter_spacing2 * this->config->external_perimeter_overlap.get_abs_value(1)
-            + (ext_perimeter_width + perimeter_width) * 0.5f * (1 - this->config->external_perimeter_overlap.get_abs_value(1));
-    }
-    
     // overhang perimeters
-    this->_mm3_per_mm_overhang      = this->overhang_flow.mm3_per_mm();
+    this->_mm3_per_mm_overhang = this->overhang_flow.mm3_per_mm();
-    
+
     // solid infill
-    coord_t solid_infill_spacing    = this->solid_infill_flow.scaled_spacing();
+    coord_t solid_infill_spacing = this->solid_infill_flow.scaled_spacing();
+
+    //infill / perimeter
+    coord_t infill_peri_overlap = (coord_t)scale_(this->config->get_abs_value("infill_overlap", unscale<coordf_t>(perimeter_spacing + solid_infill_spacing) / 2));
+    // infill gap to add vs periemter (useful if using perimeter bonding)
+    coord_t infill_gap = 0;
+
 
     // nozzle diameter
     const double nozzle_diameter = this->print_config->nozzle_diameter.get_at(this->config->perimeter_extruder - 1);
+
+    // perimeter conding set.
+    if (this->perimeter_flow.spacing_ratio == 1
+        && this->ext_perimeter_flow.spacing_ratio == 1
+        && this->config->external_perimeters_first
+        && this->object_config->perimeter_bonding.value > 0) {
+        infill_gap = (1 - this->object_config->perimeter_bonding.get_abs_value(1)) * ext_perimeter_spacing;
+        ext_perimeter_spacing2 -= infill_gap;
+    }
     
     // Calculate the minimum required spacing between two adjacent traces.
     // This should be equal to the nominal flow spacing but we experiment
@@ -88,7 +100,7 @@ void PerimeterGenerator::process()
         this->_lower_slices_p = offset(*this->lower_slices, double(scale_(config->overhangs_width.get_abs_value(nozzle_diameter))));
     }
 
-    // have to grown the periemters if mill post-process
+    // have to grown the perimeters if mill post-process
     MillingPostProcess miller(this->slices, this->lower_slices, config, object_config, print_config);
     bool have_to_grow_for_miller =  miller.can_be_milled(layer) && config->milling_extra_size.get_abs_value(1) > 0;
     ExPolygons unmillable;
@@ -218,7 +230,6 @@ void PerimeterGenerator::process()
                                     //it's not dangerous as it will be intersected by 'unsupported' later
                                     //FIXME: add overlap in this->fill_surfaces->append
                                     //FIXME: it overlap inside unsuppported not-bridgeable area!
-                                    double overlap = scale_(this->config->get_abs_value("infill_overlap", unscale<double>(perimeter_spacing)));
 
                                     //bridgeable_simplified = offset2_ex(bridgeable_simplified, (double)-perimeter_spacing, (double)perimeter_spacing * 2);
                                     //ExPolygons unbridgeable = offset_ex(diff_ex(unsupported, bridgeable_simplified), perimeter_spacing * 3 / 2);
@@ -391,7 +402,7 @@ void PerimeterGenerator::process()
                 if ( this->config->extra_perimeters_overhangs && !last.empty() && !overhangs_unsupported.empty()) {
                     overhangs_unsupported = intersection_ex(overhangs_unsupported, last, true);
                     if (overhangs_unsupported.size() > 0) {
-                        //please don't stop adding periemter yet.
+                        //please don't stop adding perimeter yet.
                         has_overhang = true;
                     }
                 }
@@ -456,9 +467,9 @@ void PerimeterGenerator::process()
                             ExPolygons thin = offset_ex(half_thin, double(min_width / 2));
                             assert(thin.size() <= 1);
                             if (thin.empty()) continue;
-                            coord_t overlap = (coord_t)scale_(this->config->thin_walls_overlap.get_abs_value(this->ext_perimeter_flow.nozzle_diameter));
+                            coord_t thin_walls_overlap = (coord_t)scale_(this->config->thin_walls_overlap.get_abs_value(this->ext_perimeter_flow.nozzle_diameter));
                             ExPolygons anchor = intersection_ex(offset_ex(half_thin, double(min_width / 2) +
-                                (float)(overlap), jtSquare), no_thin_zone, true);
+                                (float)(thin_walls_overlap), jtSquare), no_thin_zone, true);
                             ExPolygons bounds = union_ex(thin, anchor, true);
                             for (ExPolygon &bound : bounds) {
                                 if (!intersection_ex(thin[0], bound).empty()) {
@@ -472,7 +483,7 @@ void PerimeterGenerator::process()
                                             min_width, coord_t(this->layer->height) };
                                         ma.use_bounds(bound)
                                             .use_min_real_width((coord_t)scale_(this->ext_perimeter_flow.nozzle_diameter))
-                                            .use_tapers(overlap)
+                                            .use_tapers(thin_walls_overlap)
                                             .build(thin_walls);
                                     }
                                     break;
@@ -818,7 +829,7 @@ void PerimeterGenerator::process()
                 last = diff_ex(to_polygons(last), gap_fill.polygons_covered_by_width(10.f));
             }
         }
-        //TODO: if a gapfill extrusion is a loop and with width always >= periemter width then change the type to perimeter and put it at the right place in the loops vector.
+        //TODO: if a gapfill extrusion is a loop and with width always >= perimeter width then change the type to perimeter and put it at the right place in the loops vector.
 
         // create one more offset to be used as boundary for fill
         // we offset by half the perimeter spacing (to get to the actual infill boundary)
@@ -832,9 +843,8 @@ void PerimeterGenerator::process()
                 // two or more loops?
                 perimeter_spacing / 2;
         // only apply infill overlap if we actually have one perimeter
-        coord_t overlap = 0;
+        if (inset == 0) {
-        if (inset > 0) {
+            infill_peri_overlap = 0;
-            overlap = (coord_t)scale_(this->config->get_abs_value("infill_overlap", unscale<coordf_t>(inset + solid_infill_spacing / 2)));
         }
         // simplify infill contours according to resolution
         Polygons not_filled_p;
@@ -846,14 +856,14 @@ void PerimeterGenerator::process()
         // append infill areas to fill_surfaces
         //auto it_surf = this->fill_surfaces->surfaces.end();
         ExPolygons infill_exp = offset2_ex(not_filled_exp,
-            -inset - min_perimeter_infill_spacing / 2 + overlap,
+            -inset - min_perimeter_infill_spacing / 2 + infill_peri_overlap - infill_gap,
             (float)min_perimeter_infill_spacing / 2);
         this->fill_surfaces->append(infill_exp, stPosInternal | stDensSparse);
             
-        if (overlap != 0) {
+        if (infill_peri_overlap != 0) {
             ExPolygons polyWithoutOverlap = offset2_ex(
                 not_filled_exp,
-                -inset - min_perimeter_infill_spacing / 2,
+                -inset - infill_gap - min_perimeter_infill_spacing / 2,
                 (float) min_perimeter_infill_spacing / 2);
             this->fill_no_overlap.insert(this->fill_no_overlap.end(), polyWithoutOverlap.begin(), polyWithoutOverlap.end());
         }

src/libslic3r/PrintConfig.cpp

@@ -729,12 +729,45 @@ void PrintConfigDef::init_fff_params()
     def->label = L("external perimeter overlap");
     def->full_label = L("Ext. peri. overlap");
     def->category = OptionCategory::width;
-    def->tooltip = L("This perimeter allow you to reduce the overlap between the perimeters and the external one, to reduce the impact of the perimeters artifacts."
+    def->tooltip = L("This setting allow you to reduce the overlap between the perimeters and the external one, to reduce the impact of the perimeters artifacts."
+        " 100% means that no gaps is left, and 0% means that the external perimeter isn't contributing to the overlap with the 'inner' one."
         "\nIt's very experimental, please report about the usefulness. It may be removed if there is no use of it.");
     def->sidetext = L("%");
+    def->min = 0;
+    def->max = 100;
     def->mode = comExpert;
     def->set_default_value(new ConfigOptionPercent(100));
 
+    def = this->add("perimeter_overlap", coPercent);
+    def->label = L("perimeter overlap");
+    def->full_label = L("Perimeter overlap");
+    def->category = OptionCategory::width;
+    def->tooltip = L("This setting allow you to reduce the overlap between the perimeters, to reduce the impact of the perimeters artifacts."
+        " 100% means that no gaps is left, and 0% means that perimeters are not touching each other anymore."
+        "\nIt's very experimental, please report about the usefulness. It may be removed if there is no use for it.");
+    def->sidetext = L("%");
+    def->min = 0;
+    def->max = 100;
+    def->mode = comExpert;
+    def->set_default_value(new ConfigOptionPercent(100));
+
+    def = this->add("perimeter_bonding", coPercent);
+    def->label = L("Better bonding");
+    def->full_label = L("Perimeter bonding");
+    def->category = OptionCategory::perimeter;
+    def->tooltip = L("This setting may degrad a bit the quality of your external perimeter, in exchange for a better bonding between perimeters."
+        "Use it if you have great difficulties with perimeter bonding, for example with high temperature filaments."
+        "\nThis percentage is the % of overlap between perimeters, a bit like perimeter_overlap and external_perimeter_overlap, but in reverse."
+        " You have to set perimeter_overlap and external_perimeter_overlap to 100%, or this setting has no effect."
+        " 0: no effect, 50%: half of the nozzle will be over an already extruded perimeter while extruding a new one"
+        ", unless it's an external ones)."
+        "\nIt's very experimental, please report about the usefulness. It may be removed if there is no use for it.");
+    def->sidetext = L("%");
+    def->min = 0;
+    def->max = 50;
+    def->mode = comExpert;
+    def->set_default_value(new ConfigOptionPercent(0));
+
     def = this->add("external_perimeter_speed", coFloatOrPercent);
     def->label = L("External");
     def->full_label = L("External perimeters speed");
@@ -2022,7 +2055,7 @@ void PrintConfigDef::init_fff_params()
     def->label = L("minimum top width for infill");
     def->category = OptionCategory::speed;
     def->tooltip = L("If a top surface has to be printed and it's partially covered by an other layer, it won't be considered at a top layer where his width is below this value."
-        " This can be useful to not let the 'one perimeter on top' trigger on surface that should be covered only by periemters."
+        " This can be useful to not let the 'one perimeter on top' trigger on surface that should be covered only by perimeters."
         " This value can be a mm or a % of the perimeter extrusion width.");
     def->sidetext = L("mm or %");
     def->ratio_over = "perimeter_extrusion_width";

src/libslic3r/PrintConfig.hpp

@@ -494,6 +494,7 @@ public:
     ConfigOptionBool                dont_support_bridges;
     ConfigOptionPercent             external_perimeter_cut_corners;
     ConfigOptionBool                exact_last_layer_height;
+    ConfigOptionPercent             external_perimeter_overlap;
     ConfigOptionFloatOrPercent      extrusion_width;
     ConfigOptionFloatOrPercent      first_layer_height;
     ConfigOptionFloat               first_layer_size_compensation;
@@ -503,6 +504,8 @@ public:
     ConfigOptionBool                interface_shells;
     ConfigOptionFloat               layer_height;
     ConfigOptionFloat               model_precision;
+    ConfigOptionPercent             perimeter_bonding;
+    ConfigOptionPercent             perimeter_overlap;
     ConfigOptionInt                 raft_layers;
     ConfigOptionEnum<SeamPosition>  seam_position;
     ConfigOptionBool                seam_travel;
@@ -555,6 +558,7 @@ protected:
         OPT_PTR(dont_support_bridges);
         OPT_PTR(external_perimeter_cut_corners);
         OPT_PTR(exact_last_layer_height);
+        OPT_PTR(external_perimeter_overlap);
         OPT_PTR(extrusion_width);
         OPT_PTR(hole_size_compensation);
         OPT_PTR(first_layer_height);
@@ -563,6 +567,8 @@ protected:
         OPT_PTR(interface_shells);
         OPT_PTR(layer_height);
         OPT_PTR(model_precision);
+        OPT_PTR(perimeter_bonding);
+        OPT_PTR(perimeter_overlap);
         OPT_PTR(raft_layers);
         OPT_PTR(seam_position);
         OPT_PTR(seam_travel);
@@ -621,7 +627,6 @@ public:
     ConfigOptionBool                enforce_full_fill_volume;
     ConfigOptionFloatOrPercent      external_infill_margin;
     ConfigOptionFloatOrPercent      external_perimeter_extrusion_width;
-    ConfigOptionPercent             external_perimeter_overlap;
     ConfigOptionFloatOrPercent      external_perimeter_speed;
     ConfigOptionBool                external_perimeters_first;
     ConfigOptionBool                external_perimeters_vase;
@@ -709,7 +714,6 @@ protected:
         OPT_PTR(enforce_full_fill_volume);
         OPT_PTR(external_infill_margin);
         OPT_PTR(external_perimeter_extrusion_width);
-        OPT_PTR(external_perimeter_overlap);
         OPT_PTR(external_perimeter_speed);
         OPT_PTR(external_perimeters_first);
         OPT_PTR(external_perimeters_vase);

src/slic3r/GUI/ConfigManipulation.cpp

@@ -305,7 +305,7 @@ void ConfigManipulation::toggle_print_fff_options(DynamicPrintConfig* config)
     toggle_field("overhangs_reverse_threshold", config->opt_bool("overhangs_reverse"));
     toggle_field("min_width_top_surface", config->opt_bool("only_one_perimeter_top"));
 
-    for (auto el : { "external_perimeters_vase", "external_perimeters_nothole", "external_perimeters_hole"})
+    for (auto el : { "external_perimeters_vase", "external_perimeters_nothole", "external_perimeters_hole", "perimeter_bonding"})
         toggle_field(el, config->opt_bool("external_perimeters_first"));
 
     for (auto el : { "thin_walls_min_width", "thin_walls_overlap" })

src/slic3r/GUI/Preset.cpp

@@ -536,6 +536,8 @@ const std::vector<std::string>& Preset::print_options()
         "print_extrusion_multiplier",
         "external_perimeter_cut_corners",
         "external_perimeter_overlap",
+        "perimeter_bonding",
+        "perimeter_overlap",
         "milling_after_z",
         "milling_post_process",
         "milling_extra_size",

src/slic3r/GUI/PresetHints.cpp

@@ -319,6 +319,9 @@ std::string PresetHints::recommended_thin_wall_thickness(const PresetBundle &pre
         *print_config.opt<ConfigOptionFloatOrPercent>("perimeter_extrusion_width"), 
         nozzle_diameter, layer_height, false);
 
+    //set spacing
+    external_perimeter_flow.spacing_ratio = print_config.opt<ConfigOptionPercent>("external_perimeter_overlap")->get_abs_value(1);
+    perimeter_flow.spacing_ratio = print_config.opt<ConfigOptionPercent>("perimeter_overlap")->get_abs_value(1);
     
     if (num_perimeters > 0) {
         int num_lines = std::min(num_perimeters, 6);