Fine tuning parameters and fixing pad wings when greater gaps are used.

src/libslic3r/PrintConfig.cpp

@@ -2502,7 +2502,7 @@ void PrintConfigDef::init_sla_params()
     def->min = 0;
     def->max = 10;
     def->mode = comExpert;
-    def->set_default_value(new ConfigOptionFloat(0.5));
+    def->set_default_value(new ConfigOptionFloat(1));
 
     def = this->add("support_critical_angle", coFloat);
     def->label = L("Critical angle");
@@ -2625,6 +2625,17 @@ void PrintConfigDef::init_sla_params()
     def->mode = comAdvanced;
     def->set_default_value(new ConfigOptionFloat(45.0));
     
+    def = this->add("pad_object_gap", coFloat);
+    def->label = L("Pad object gap");
+    def->category = L("Pad");
+    def->tooltip  = L("The gap between the object bottom and the generated "
+                      "pad in zero elevation mode.");
+    def->sidetext = L("mm");
+    def->min = 0;
+    def->max = 10;
+    def->mode = comExpert;
+    def->set_default_value(new ConfigOptionFloat(1));
+    
     def = this->add("pad_object_connector_stride", coFloat);
     def->label = L("Pad object connector stride");
     def->category = L("Pad");
@@ -2643,7 +2654,7 @@ void PrintConfigDef::init_sla_params()
     def->sidetext = L("mm");
     def->min = 0;
     def->mode = comExpert;
-    def->set_default_value(new ConfigOptionFloat(0.3));
+    def->set_default_value(new ConfigOptionFloat(0.5));
     
     def = this->add("pad_object_connector_penetration", coFloat);
     def->label = L("Pad object connector penetration");

src/libslic3r/PrintConfig.hpp

@@ -1033,6 +1033,9 @@ public:
     //    - The two pads will be connected with tiny connector sticks
     // /////////////////////////////////////////////////////////////////////////
     
+    // This is the gap between the object bottom and the generated pad
+    ConfigOptionFloat pad_object_gap;
+    
     // How far to place the connector sticks on the object pad perimeter
     ConfigOptionFloat pad_object_connector_stride;
     
@@ -1071,6 +1074,7 @@ protected:
         OPT_PTR(pad_max_merge_distance);
         OPT_PTR(pad_edge_radius);
         OPT_PTR(pad_wall_slope);
+        OPT_PTR(pad_object_gap);
         OPT_PTR(pad_object_connector_stride);
         OPT_PTR(pad_object_connector_width);
         OPT_PTR(pad_object_connector_penetration);

src/libslic3r/SLA/SLABasePool.cpp

@@ -383,18 +383,12 @@ Polygons unify(const Polygons& shapes) {
 // inserted along the perimeter in every "stride" distance. The stick rectangles
 // will have a with about "stick_width". The input dimensions are in world 
 // measure, not the scaled clipper units.
-void offset_with_breakstick_holes(ExPolygon& poly,
-                                  double padding,
-                                  double stride,
-                                  double stick_width,
-                                  double penetration)
-{
-    // We do the basic offsetting first
-    static const bool dont_round_edges = false;
-    
-    if(padding > 0.0)
-        offset(poly, coord_t(padding / SCALING_FACTOR), dont_round_edges);
-
+void breakstick_holes(ExPolygon& poly,
+                      double padding,
+                      double stride,
+                      double stick_width,
+                      double penetration)
+{   
     // SVG svg("bridgestick_plate.svg");
     // svg.draw(poly);
 
@@ -428,8 +422,8 @@ void offset_with_breakstick_holes(ExPolygon& poly,
             out.emplace_back(a);
 
             // dodge the start point, do not make sticks on the joins
-            while (t < sright) t += sright;
-            double tend = nrm - sright;
+            while (t < sbottom) t += sbottom;
+            double tend = nrm - sbottom;
 
             while (t < tend) { // insert the stick on the polygon perimeter
 

src/libslic3r/SLA/SLABasePool.hpp

@@ -30,11 +30,11 @@ void base_plate(const TriangleMesh& mesh,       // input mesh
 // inserted along the perimeter in every "stride" distance. The stick rectangles
 // will have a with about "stick_width". The input dimensions are in world 
 // measure, not the scaled clipper units.
-void offset_with_breakstick_holes(ExPolygon& poly,
-                                  double padding,
-                                  double stride,
-                                  double stick_width,
-                                  double penetration = 0.0);
+void breakstick_holes(ExPolygon &poly,
+                      double     padding,
+                      double     stride,
+                      double     stick_width,
+                      double     penetration = 0.0);
 
 struct PoolConfig {
     double min_wall_thickness_mm = 2;

src/libslic3r/SLA/SLASupportTree.cpp

@@ -578,23 +578,31 @@ struct Pad {
                    float(cfg.min_wall_height_mm + cfg.min_wall_thickness_mm),
                    0.1f, pcfg.throw_on_cancel);
         
-        // We don't need the holes for the base plate from the supports
         for (const ExPolygon &bp : platetmp)  basep.emplace_back(bp.contour);
-        for (const ExPolygon &bp : modelbase) basep.emplace_back(bp.contour);
+        
         
         if(pcfg.embed_object) {
-            
             auto modelbase_sticks = modelbase;
-            for(auto& poly : modelbase_sticks)
-                sla::offset_with_breakstick_holes(
+            
+            if (pcfg.embed_object.object_gap_mm > 0.0)
+                modelbase_sticks
+                    = offset_ex(modelbase_sticks,
+                                coord_t(pcfg.embed_object.object_gap_mm
+                                        / SCALING_FACTOR));
+            
+            for(auto& poly : modelbase_sticks) {
+                basep.emplace_back(poly);
+                sla::breakstick_holes(
                     poly,
                     pcfg.embed_object.object_gap_mm,   // padding
                     pcfg.embed_object.stick_stride_mm,
                     pcfg.embed_object.stick_width_mm,
                     pcfg.embed_object.stick_penetration_mm);
+            }
 
             create_base_pool(basep, tmesh, modelbase_sticks, cfg);
         } else {
+            for (const ExPolygon &bp : modelbase) basep.emplace_back(bp.contour);
             create_base_pool(basep, tmesh, {}, cfg);
         }
 

src/libslic3r/SLAPrint.cpp

@@ -602,17 +602,18 @@ sla::SupportConfig make_support_cfg(const SLAPrintObjectConfig& c) {
     return scfg;
 }
 
-sla::PoolConfig::EmbedObject use_builtin_pad(const SLAPrintObjectConfig& c) {
+sla::PoolConfig::EmbedObject builtin_pad_cfg(const SLAPrintObjectConfig& c) {
     sla::PoolConfig::EmbedObject ret;
     
     ret.enabled = c.support_object_elevation.getFloat() <= EPSILON && 
                   c.pad_enable.getBool();
     
     if(ret.enabled) {
-        ret.object_gap_mm   = c.support_base_safety_distance.getFloat();
-        ret.stick_width_mm  = c.pad_object_connector_width.getFloat();
-        ret.stick_stride_mm = c.pad_object_connector_stride.getFloat();
-        ret.stick_width_mm  = c.pad_object_connector_penetration.getFloat();
+        ret.object_gap_mm        = c.pad_object_gap.getFloat();
+        ret.stick_width_mm       = c.pad_object_connector_width.getFloat();
+        ret.stick_stride_mm      = c.pad_object_connector_stride.getFloat();
+        ret.stick_penetration_mm = c.pad_object_connector_penetration
+                                    .getFloat();
     }
     
     return ret;
@@ -631,7 +632,7 @@ sla::PoolConfig make_pool_config(const SLAPrintObjectConfig& c) {
     pcfg.min_wall_height_mm = c.pad_wall_height.getFloat();
 
     // set builtin pad implicitly ON
-    pcfg.embed_object = use_builtin_pad(c);
+    pcfg.embed_object = builtin_pad_cfg(c);
     
     return pcfg;
 }
@@ -663,6 +664,16 @@ std::string SLAPrint::validate() const
 
         if(supports_en && elv > EPSILON && elv < pinhead_width )
             return L("Elevation is too low for object.");
+        
+        sla::PoolConfig::EmbedObject builtinpad = builtin_pad_cfg(po->config());
+        if(supports_en && builtinpad.enabled &&
+           cfg.pillar_base_safety_distance_mm < builtinpad.object_gap_mm) {
+            return L(
+                "The endings of the support pillars will be deployed on the "
+                "gap between the object and the pad. 'Support base safety "
+                "distance' has to be greater than the 'Pad object gap' "
+                "parameter to avoid this.");
+        }
     }
 
     return "";
@@ -861,7 +872,7 @@ void SLAPrint::process()
         
         // If the builtin pad mode is engaged, we have to filter out all the
         // points that are on the bottom of the object
-        if(use_builtin_pad(po.m_config)) {
+        if(builtin_pad_cfg(po.m_config)) {
             double gnd   = po.m_supportdata->emesh.ground_level();
             auto & pts   = po.m_supportdata->support_points;
             
@@ -1658,6 +1669,7 @@ bool SLAPrintObject::invalidate_state_by_config_options(const std::vector<t_conf
             || opt_key == "pad_max_merge_distance"
             || opt_key == "pad_wall_slope"
             || opt_key == "pad_edge_radius"
+            || opt_key == "pad_object_gap"
             || opt_key == "pad_object_connector_stride"
             || opt_key == "pad_object_connector_width"
             || opt_key == "pad_object_connector_penetration"

src/slic3r/GUI/Preset.cpp

@@ -475,6 +475,7 @@ const std::vector<std::string>& Preset::sla_print_options()
             "pad_max_merge_distance",
             "pad_edge_radius",
             "pad_wall_slope",
+            "pad_object_gap",
             "pad_object_connector_stride",
             "pad_object_connector_width",
             "pad_object_connector_penetration",

src/slic3r/GUI/Tab.cpp

@@ -3503,6 +3503,7 @@ void TabSLAPrint::build()
 //    optgroup->append_single_option_line("pad_edge_radius");
     optgroup->append_single_option_line("pad_wall_slope");
     
+    optgroup->append_single_option_line("pad_object_gap");
     optgroup->append_single_option_line("pad_object_connector_stride");
     optgroup->append_single_option_line("pad_object_connector_width");
     optgroup->append_single_option_line("pad_object_connector_penetration");