diff --git a/Polyhedron/demo/Polyhedron/Polyhedron_demo_mesh_segmentation_plugin.cpp b/Polyhedron/demo/Polyhedron/Polyhedron_demo_mesh_segmentation_plugin.cpp
index 98a1e6fb3a2..d9850db9051 100644
--- a/Polyhedron/demo/Polyhedron/Polyhedron_demo_mesh_segmentation_plugin.cpp
+++ b/Polyhedron/demo/Polyhedron/Polyhedron_demo_mesh_segmentation_plugin.cpp
@@ -111,6 +111,7 @@ void Polyhedron_demo_mesh_segmentation_plugin::on_SDF_button_clicked()
     {
         // create new item
         new_item = new Scene_polyhedron_item(*item->polyhedron()); 
+        new_item->setGouraudMode();
         item->setVisible(false);             
         index = scene->addItem(new_item); 
         
@@ -161,6 +162,7 @@ void Polyhedron_demo_mesh_segmentation_plugin::on_Partition_button_clicked()
     {
         // create new item
         new_item = new Scene_polyhedron_item(*item->polyhedron()); 
+        new_item->setGouraudMode();
         item->setVisible(false);             
         index = scene->addItem(new_item); 
         
@@ -225,11 +227,7 @@ void Polyhedron_demo_mesh_segmentation_plugin::colorize(
         if(sdf)
         {
             double sdf_value = segmentation.get_sdf_value_of_facet(facet_const_it); 
-            facet_sdf_values.push_back(std::pair<Polyhedron::Facet_iterator, double>(facet_it, sdf_value));          
-            //int sdf_color = static_cast<int>(255.0 * sdf_value);
-            //
-            //color_vector.push_back(QColor(sdf_color,sdf_color,sdf_color));  
-            //facet_it->set_patch_id(patch_id++);          
+            facet_sdf_values.push_back(std::pair<Polyhedron::Facet_iterator, double>(facet_it, sdf_value));                 
         }
         else
         {
diff --git a/Surface_mesh_segmentation/include/CGAL/Surface_mesh_segmentation.h b/Surface_mesh_segmentation/include/CGAL/Surface_mesh_segmentation.h
index e43161c2f88..fd9aba2a2d7 100644
--- a/Surface_mesh_segmentation/include/CGAL/Surface_mesh_segmentation.h
+++ b/Surface_mesh_segmentation/include/CGAL/Surface_mesh_segmentation.h
@@ -112,6 +112,11 @@ public:
     : mesh(mesh), facet_index_map(facet_index_map), is_pmmap_custom(true) {
   }
 
+// Copy-constructor
+// Default, we store facet-to-id in property-map adaptor 'FacetIndexMap'.
+// It stores a pointer to std::map instance which is a member variable.
+// So default copy constructor is not working since copied property-map adaptor still
+// points to std::map instance which exists in copied object (rhs).
   Surface_mesh_segmentation(const
                             Surface_mesh_segmentation<Polyhedron, FacetIndexMap>& rhs):
     mesh(rhs.mesh), sdf_values(rhs.sdf_values), centers(rhs.centers),
@@ -123,8 +128,9 @@ public:
     }
   }
 
-// use another copy of polyhedron but also copy state of rhs
-// main difference between copy constructor is rhs.mesh is not equal to mesh.
+// Use another copy of polyhedron but also copy the state of rhs.
+// Main difference between copy constructor is rhs.mesh is NOT equal to this->mesh.
+// So we cannot copy facet_index_map_internal since facet_iterators of 'this' is different than rhs.
   Surface_mesh_segmentation(const Polyhedron& mesh,
                             const Surface_mesh_segmentation<Polyhedron, FacetIndexMap>& rhs)
     : mesh(mesh), sdf_values(rhs.sdf_values), centers(rhs.centers),