First experiments with sla supports ui

xs/src/libslic3r/Model.hpp

@@ -79,6 +79,8 @@ public:
     // Only if the user really modified the layer height, layer_height_profile_valid is set
     // and used subsequently by the PrintObject.
     bool                    layer_height_profile_valid;
+    
+    std::vector<Vec3f>      sla_support_points;
 
     /* This vector accumulates the total translation applied to the object by the
         center_around_origin() method. Callers might want to apply the same translation