Allow to set shell thickness for top/bottom layers (#4430)

* Fix a warning in PresetEditor line 806.

* Remove min_shell_thickness from the if condition in  LayerRegion.cpp

* Add missing line in spiral vase check.

* Add initial set top shell thickness.

* Add minimum shell thickness for top/bottom layers.

* Some refactoring.

* Some Fixes.

* revert last change.

* a fix.

* Some refactoring.

* Some fix in calculating solid layers count.

* Refactoring in LayerRegion.cpp, Object.pm and PresetEditor.pm

lib/Slic3r/Config.pm

@@ -191,6 +191,7 @@ sub validate {
     die "Invalid value for --solid-layers\n" if defined $self->solid_layers && $self->solid_layers < 0;
     die "Invalid value for --top-solid-layers\n"    if $self->top_solid_layers      < 0;
     die "Invalid value for --bottom-solid-layers\n" if $self->bottom_solid_layers   < 0;
+    die "Invalid value for --min-top-bottom-shell-thickness\n" if $self->min_top_bottom_shell_thickness < 0;
     
     # --gcode-flavor
     die "Invalid value for --gcode-flavor\n"

lib/Slic3r/GUI/PresetEditor.pm

@@ -438,7 +438,7 @@ sub options {
         layer_height first_layer_height
         adaptive_slicing adaptive_slicing_quality match_horizontal_surfaces
         perimeters spiral_vase
-        top_solid_layers min_shell_thickness bottom_solid_layers
+        top_solid_layers min_shell_thickness min_top_bottom_shell_thickness bottom_solid_layers
         extra_perimeters avoid_crossing_perimeters thin_walls overhangs
         seam_position external_perimeters_first
         fill_density fill_pattern top_infill_pattern bottom_infill_pattern fill_gaps
@@ -532,6 +532,8 @@ sub build {
             $line->append_option($optgroup->get_option('top_solid_layers'));
             $line->append_option($optgroup->get_option('bottom_solid_layers'));
             $optgroup->append_line($line);
+
+            $optgroup->append_single_option_line('min_top_bottom_shell_thickness');
         }
         {
             my $optgroup = $page->new_optgroup('Quality (slower slicing)');
@@ -622,7 +624,7 @@ sub build {
             $optgroup->append_single_option_line('dont_support_bridges');
         }
     }
-    
+
     {
         my $page = $self->add_options_page('Speed', 'time.png');
         {
@@ -802,11 +804,12 @@ sub _update {
     $opt_key = "all_keys" if (length($key // '') == 0); 
     my $config = $self->{config};
 
-    if (any { /$opt_key/ } qw(all_keys spiral_vase perimeters top_solid_layers fill_density support_material min_shell_thickness)) {
+    if (any { /$opt_key/ } qw(all_keys spiral_vase perimeters top_solid_layers fill_density support_material min_shell_thickness min_top_bottom_shell_thickness)) {
-        if ($config->spiral_vase && !($config->perimeters == 1 && $config->min_shell_thickness == 0 && $config->top_solid_layers == 0 && $config->fill_density == 0 && $config->support_material == 0)) {
+        if ($config->spiral_vase && !($config->perimeters == 1 && $config->min_shell_thickness == 0 && $config->min_top_bottom_shell_thickness == 0 && $config->top_solid_layers == 0 && $config->fill_density == 0 && $config->support_material == 0)) {
             my $dialog = Wx::MessageDialog->new($self,
                 "The Spiral Vase mode requires:\n"
                 . "- one perimeter\n"
+                . "- shell thickness to be 0\n"
                 . "- no top solid layers\n"
                 . "- 0% fill density\n"
                 . "- no support material\n"
@@ -816,6 +819,7 @@ sub _update {
                 my $new_conf = Slic3r::Config->new;
                 $new_conf->set("perimeters", 1);
                 $new_conf->set("min_shell_thickness", 0);
+                $new_conf->set("min_top_bottom_shell_thickness", 0);
                 $new_conf->set("top_solid_layers", 0);
                 $new_conf->set("fill_density", 0);
                 $new_conf->set("support_material", 0);
@@ -901,7 +905,7 @@ sub _update {
                     solid_infill_below_area infill_extruder);
     }
 
-    my $have_solid_infill = ($config->top_solid_layers > 0) || ($config->bottom_solid_layers > 0);
+    my $have_solid_infill = ($config->top_solid_layers > 0) || ($config->bottom_solid_layers > 0) || ($config->min_top_bottom_shell_thickness > 0);
     if (any { /$opt_key/ } qw(all_keys top_solid_layers bottom_solid_layers)) {
         # solid_infill_extruder uses the same logic as in Print::extruders()
         $self->get_field($_)->toggle($have_solid_infill)
@@ -919,7 +923,7 @@ sub _update {
         $self->get_field('gap_fill_speed')->toggle($have_perimeters && $have_infill && $config->fill_gaps);
     }
 
-    my $have_top_solid_infill = ($config->top_solid_layers > 0) || ($config->min_shell_thickness > 0);
+    my $have_top_solid_infill = ($config->top_solid_layers > 0) || ($config->min_top_bottom_shell_thickness > 0);
 
     $self->get_field($_)->toggle($have_top_solid_infill)
         for qw(top_infill_extrusion_width top_solid_infill_speed);

lib/Slic3r/Print/Object.pm

@@ -3,6 +3,7 @@ package Slic3r::Print::Object;
 use strict;
 use warnings;
 
+use POSIX;
 use List::Util qw(min max sum first any);
 use Slic3r::Flow ':roles';
 use Slic3r::Geometry qw(X Y Z PI scale unscale chained_path epsilon);
@@ -387,10 +388,21 @@ sub discover_horizontal_shells {
                 ];
                 next if !@$solid;
                 Slic3r::debugf "Layer %d has %s surfaces\n", $i, ($type == S_TYPE_TOP) ? 'top' : 'bottom';
-                
+
                 my $solid_layers = ($type == S_TYPE_TOP)
                     ? $layerm->region->config->top_solid_layers
                     : $layerm->region->config->bottom_solid_layers;
+
+                if ($layerm->region->config->min_top_bottom_shell_thickness > 0) {
+                    my $current_shell_thickness = $solid_layers * $self->get_layer($i)->height;
+                    my $minimum_shell_thickness = $layerm->region->config->min_top_bottom_shell_thickness;
+
+                    while ($minimum_shell_thickness - $current_shell_thickness > epsilon) {
+                        $solid_layers++;
+                        $current_shell_thickness = $solid_layers * $self->get_layer($i)->height;
+                    }
+                }
+
                 NEIGHBOR: for (my $n = ($type == S_TYPE_TOP) ? $i-1 : $i+1; 
                         abs($n - $i) <= $solid_layers-1; 
                         ($type == S_TYPE_TOP) ? $n-- : $n++) {

xs/src/libslic3r/LayerRegion.cpp

@@ -237,26 +237,25 @@ LayerRegion::prepare_fill_surfaces()
         the only meaningful information returned by psPerimeters. */
     
     // if no solid layers are requested, turn top/bottom surfaces to internal
-    if (this->region()->config.min_shell_thickness == 0) {
+    if (this->region()->config.top_solid_layers == 0 && this->region()->config.min_top_bottom_shell_thickness <= 0) {
-        if (this->region()->config.top_solid_layers == 0) {
+        for (Surfaces::iterator surface = this->fill_surfaces.surfaces.begin(); surface != this->fill_surfaces.surfaces.end(); ++surface) {
-            for (Surfaces::iterator surface = this->fill_surfaces.surfaces.begin(); surface != this->fill_surfaces.surfaces.end(); ++surface) {
+            if (surface->surface_type == stTop) {
-                if (surface->surface_type == stTop) {
+                if (this->layer()->object()->config.infill_only_where_needed) {
-                    if (this->layer()->object()->config.infill_only_where_needed) {
+                    surface->surface_type = stInternalVoid;
-                        surface->surface_type = stInternalVoid;
+                } else {
-                    } else {
+                    surface->surface_type = stInternal;
-                        surface->surface_type = stInternal;
-                    }
                 }
             }
         }
-        if (this->region()->config.bottom_solid_layers == 0) {
+    }
-            for (Surfaces::iterator surface = this->fill_surfaces.surfaces.begin(); surface != this->fill_surfaces.surfaces.end(); ++surface) {
+    
-                if (surface->surface_type == stBottom || surface->surface_type == stBottomBridge)
+    if (this->region()->config.bottom_solid_layers == 0 && this->region()->config.min_top_bottom_shell_thickness <= 0) {
-                    surface->surface_type = stInternal;
+        for (Surfaces::iterator surface = this->fill_surfaces.surfaces.begin(); surface != this->fill_surfaces.surfaces.end(); ++surface) {
-            }
+            if (surface->surface_type == stBottom || surface->surface_type == stBottomBridge)
+                surface->surface_type = stInternal;
         }
     }
-        
+
     // turn too small internal regions into solid regions according to the user setting
     const float &fill_density = this->region()->config.fill_density;
     if (fill_density > 0 && fill_density < 100) {

xs/src/libslic3r/Print.cpp

@@ -338,7 +338,9 @@ Print::object_extruders() const
         if ((*region)->config.fill_density.value > 0)
             extruders.insert((*region)->config.infill_extruder - 1);
         
-        if ((*region)->config.top_solid_layers.value > 0 || (*region)->config.bottom_solid_layers.value > 0)
+        if ((*region)->config.top_solid_layers.value > 0
+            || (*region)->config.bottom_solid_layers.value > 0
+            || (*region)->config.min_top_bottom_shell_thickness.value > 0)
             extruders.insert((*region)->config.solid_infill_extruder - 1);
     }
     

xs/src/libslic3r/PrintConfig.cpp

@@ -837,6 +837,15 @@ PrintConfigDef::PrintConfigDef()
     def->min = 0;
     def->default_value = new ConfigOptionFloat(0);
 
+    def = this->add("min_top_bottom_shell_thickness", coFloat);
+    def->label = "Minimum shell thickness";
+    def->category = "Layers and Perimeters";
+    def->sidetext = "mm";
+    def->tooltip = "Alternative method of configuring top/bottom layers. If this is above 0 extra solid layers will be generated when necessary";
+    def->cli = "min-vertical-shell-thickness=f";
+    def->min = 0;
+    def->default_value = new ConfigOptionFloat(0);
+
     def = this->add("min_layer_height", coFloats);
     def->label = "Min";
     def->tooltip = "This is the lowest printable layer height for this extruder and limits the resolution for adaptive slicing. Typical values are 0.1 or 0.05.";

xs/src/libslic3r/PrintConfig.hpp

@@ -256,6 +256,7 @@ class PrintRegionConfig : public virtual StaticPrintConfig
     ConfigOptionFloatOrPercent      infill_overlap;
     ConfigOptionFloat               infill_speed;
     ConfigOptionFloat               min_shell_thickness;
+    ConfigOptionFloat               min_top_bottom_shell_thickness;
     ConfigOptionBool                overhangs;
     ConfigOptionInt                 perimeter_extruder;
     ConfigOptionFloatOrPercent      perimeter_extrusion_width;
@@ -314,7 +315,8 @@ class PrintRegionConfig : public virtual StaticPrintConfig
         OPT_PTR(top_infill_pattern);
         OPT_PTR(top_solid_infill_speed);
         OPT_PTR(top_solid_layers);
-        
+        OPT_PTR(min_top_bottom_shell_thickness);
+
         return NULL;
     };
 };

xs/src/libslic3r/PrintRegion.cpp

@@ -99,6 +99,7 @@ PrintRegion::invalidate_state_by_config(const PrintConfigBase &config)
             || opt_key == "solid_infill_every_layers"
             || opt_key == "bottom_solid_layers"
             || opt_key == "top_solid_layers"
+            || opt_key == "min_top_bottom_shell_thickness"
             || opt_key == "min_shell_thickness"
             || opt_key == "infill_extruder"
             || opt_key == "solid_infill_extruder"