diff --git a/Polyhedron/demo/Polyhedron/Plugins/PMP/Selection_plugin.cpp b/Polyhedron/demo/Polyhedron/Plugins/PMP/Selection_plugin.cpp
index 7534498a7af..4bad41e70cf 100644
--- a/Polyhedron/demo/Polyhedron/Plugins/PMP/Selection_plugin.cpp
+++ b/Polyhedron/demo/Polyhedron/Plugins/PMP/Selection_plugin.cpp
@@ -777,6 +777,7 @@ public Q_SLOTS:
     case 0:
       Q_EMIT set_operation_mode(-1);
       on_Selection_type_combo_box_changed(ui_widget.Selection_type_combo_box->currentIndex());
+      selection_item->polyhedron_item()->switchToGouraudPlusEdge(false);
       break;
       //Edition mode
     case 1:
@@ -812,7 +813,13 @@ public Q_SLOTS:
   {
     Scene_polyhedron_selection_item* selection_item = getSelectedItem<Scene_polyhedron_selection_item>();
     if(selection_item)
+    {
       selection_item->on_Ctrlz_pressed();
+      if(mode == 11)
+        selection_item->polyhedron_item()->switchToGouraudPlusEdge(true);
+      else
+        selection_item->polyhedron_item()->switchToGouraudPlusEdge(false);
+    }
     if(ui_widget.selectionOrEuler->currentIndex() == 0)
     {
       Q_EMIT set_operation_mode(-1);
diff --git a/Polyhedron/demo/Polyhedron/Plugins/Surface_mesh_deformation/Scene_edit_polyhedron_item.cpp b/Polyhedron/demo/Polyhedron/Plugins/Surface_mesh_deformation/Scene_edit_polyhedron_item.cpp
index b4f7a15dfec..e15b5185976 100644
--- a/Polyhedron/demo/Polyhedron/Plugins/Surface_mesh_deformation/Scene_edit_polyhedron_item.cpp
+++ b/Polyhedron/demo/Polyhedron/Plugins/Surface_mesh_deformation/Scene_edit_polyhedron_item.cpp
@@ -944,7 +944,7 @@ void Scene_edit_polyhedron_item::draw(CGAL::Three::Viewer_interface* viewer) con
   Tc* tc = getTriangleContainer(Priv::Facets);
   tc->setColor(this->color());
   tc->draw(viewer, true);
-  drawEdges(viewer);
+  //drawEdges(viewer);
   draw_ROI_and_control_vertices(viewer);
   drawTransparent(viewer);
 }
diff --git a/Polyhedron/demo/Polyhedron/Plugins/Surface_mesh_deformation/Scene_edit_polyhedron_item.h b/Polyhedron/demo/Polyhedron/Plugins/Surface_mesh_deformation/Scene_edit_polyhedron_item.h
index aa754d89692..49b5576fd0a 100644
--- a/Polyhedron/demo/Polyhedron/Plugins/Surface_mesh_deformation/Scene_edit_polyhedron_item.h
+++ b/Polyhedron/demo/Polyhedron/Plugins/Surface_mesh_deformation/Scene_edit_polyhedron_item.h
@@ -273,7 +273,7 @@ public:
   
   // Indicate if rendering mode is supported
   bool supportsRenderingMode(RenderingMode m) const { 
-    return m == Gouraud; 
+    return m == GouraudPlusEdges;
   }
   void draw(CGAL::Three::Viewer_interface*) const;
   void drawEdges(CGAL::Three::Viewer_interface*) const;
diff --git a/Polyhedron/demo/Polyhedron/Scene.cpp b/Polyhedron/demo/Polyhedron/Scene.cpp
index 701d2f7d639..3de29f2b3b2 100644
--- a/Polyhedron/demo/Polyhedron/Scene.cpp
+++ b/Polyhedron/demo/Polyhedron/Scene.cpp
@@ -543,7 +543,7 @@ void Scene::renderScene(const QList<Scene_interface::Item_id> &items,
     }
     if(group ||item.visible())
     {
-      if( group || item.renderingMode() == Flat || item.renderingMode() == FlatPlusEdges || item.renderingMode() == Gouraud)
+      if( group || item.renderingMode() == Flat || item.renderingMode() == FlatPlusEdges || item.renderingMode() == Gouraud || item.renderingMode() == GouraudPlusEdges )
       {
         if(with_names) {
           viewer->glClearDepthf(1.0);
@@ -591,7 +591,8 @@ void Scene::renderWireScene(const QList<Scene_interface::Item_id> &items,
      {
        if( group || (!with_names && item.renderingMode() == FlatPlusEdges )
           || item.renderingMode() == Wireframe
-          || item.renderingMode() == PointsPlusNormals)
+          || item.renderingMode() == PointsPlusNormals
+          || item.renderingMode() == GouraudPlusEdges)
        {
          viewer->setGlPointSize(2.f);
          item.drawEdges(viewer);
diff --git a/Polyhedron/demo/Polyhedron/Scene_group_item.cpp b/Polyhedron/demo/Polyhedron/Scene_group_item.cpp
index 4ec4bd87c7a..1c10698db8f 100644
--- a/Polyhedron/demo/Polyhedron/Scene_group_item.cpp
+++ b/Polyhedron/demo/Polyhedron/Scene_group_item.cpp
@@ -183,7 +183,8 @@ void Scene_group_item::renderChildren(Viewer_interface *viewer,
     if(getChild(id)->visible() &&
        (getChild(id)->renderingMode() == Flat ||
         getChild(id)->renderingMode() == FlatPlusEdges ||
-        getChild(id)->renderingMode() == Gouraud))
+        getChild(id)->renderingMode() == Gouraud ||
+        getChild(id)->renderingMode() == GouraudPlusEdges))
     {
       getChild(id)->draw(viewer);
     }
@@ -191,7 +192,8 @@ void Scene_group_item::renderChildren(Viewer_interface *viewer,
     if(getChild(id)->visible() &&
        (getChild(id)->renderingMode() == FlatPlusEdges
         || getChild(id)->renderingMode() == Wireframe
-        || getChild(id)->renderingMode() == PointsPlusNormals))
+        || getChild(id)->renderingMode() == PointsPlusNormals
+        || getChild(id)->renderingMode() == GouraudPlusEdges))
     {
       getChild(id)->drawEdges(viewer);
     }
diff --git a/Polyhedron/demo/Polyhedron/Scene_item.cpp b/Polyhedron/demo/Polyhedron/Scene_item.cpp
index 7093872e5e3..17590ca5e5c 100644
--- a/Polyhedron/demo/Polyhedron/Scene_item.cpp
+++ b/Polyhedron/demo/Polyhedron/Scene_item.cpp
@@ -79,6 +79,8 @@ const char* slotName(RenderingMode mode) {
         return SLOT(setGouraudMode());
     case PointsPlusNormals:
         return SLOT(setPointsPlusNormalsMode());
+    case GouraudPlusEdges:
+        return SLOT(setGouraudPlusEdgesMode());
     default:
         Q_ASSERT(false);
         return "";
diff --git a/Polyhedron/demo/Polyhedron/Scene_polyhedron_selection_item.cpp b/Polyhedron/demo/Polyhedron/Scene_polyhedron_selection_item.cpp
index 57d91757be6..c612b965bad 100644
--- a/Polyhedron/demo/Polyhedron/Scene_polyhedron_selection_item.cpp
+++ b/Polyhedron/demo/Polyhedron/Scene_polyhedron_selection_item.cpp
@@ -1017,7 +1017,6 @@ bool Scene_polyhedron_selection_item::treat_selection(const std::set<fg_vertex_d
         {
           setProperty("need_hl_restore", true);
           set_highlighting(false);
-          qDebug()<<":coucou";
         }
         invalidateOpenGLBuffers();
         Q_EMIT updateInstructions("Ctrl+Right-click to move the point. \nHit Ctrl+Z to leave the selection. (2/2)");
@@ -1028,6 +1027,11 @@ bool Scene_polyhedron_selection_item::treat_selection(const std::set<fg_vertex_d
         temp_selected_vertices.insert(vh);
         const Point_3& p = get(vpm,vh);
         d->manipulated_frame->setPosition(p.x()+offset.x, p.y()+offset.y, p.z()+offset.z);
+        if(property("is_highlighting").toBool())
+        {
+          setProperty("need_hl_restore", true);
+          set_highlighting(false);
+        }
         invalidateOpenGLBuffers();
       }
       break;
@@ -1827,6 +1831,7 @@ Scene_polyhedron_selection_item::Scene_polyhedron_selection_item(Scene_face_grap
 
 Scene_polyhedron_selection_item::~Scene_polyhedron_selection_item()
 {
+  poly_item->switchToGouraudPlusEdge(false);
   delete d;
   Q_FOREACH(CGAL::QGLViewer* v, CGAL::QGLViewer::QGLViewerPool()){
     CGAL::Three::Viewer_interface* viewer = dynamic_cast<CGAL::Three::Viewer_interface*>(v);
diff --git a/Polyhedron/demo/Polyhedron/Scene_surface_mesh_item.cpp b/Polyhedron/demo/Polyhedron/Scene_surface_mesh_item.cpp
index 181274cd4c6..330a51c7238 100644
--- a/Polyhedron/demo/Polyhedron/Scene_surface_mesh_item.cpp
+++ b/Polyhedron/demo/Polyhedron/Scene_surface_mesh_item.cpp
@@ -125,6 +125,12 @@ struct Scene_surface_mesh_item_priv{
     alphaSlider = NULL;
     has_vcolors = false;
     has_fcolors = false;
+    supported_rendering_modes << FlatPlusEdges
+                              << Wireframe
+                              << Flat
+                              << Gouraud
+                              << GouraudPlusEdges
+                              << Points;
     item->setProperty("classname", QString("surface_mesh"));
   }
 
@@ -152,6 +158,12 @@ struct Scene_surface_mesh_item_priv{
     alphaSlider = NULL;
     has_vcolors = false;
     has_fcolors = false;
+    supported_rendering_modes << FlatPlusEdges
+                              << Wireframe
+                              << Flat
+                              << Gouraud
+                                 << GouraudPlusEdges
+                              << Points;
     item->setProperty("classname", QString("surface_mesh"));
   }
 
@@ -251,6 +263,7 @@ struct Scene_surface_mesh_item_priv{
   int genus;
   bool self_intersect;
   mutable QSlider* alphaSlider;
+  QList<RenderingMode> supported_rendering_modes;
 };
 
 const char* aabb_property_name = "Scene_surface_mesh_item aabb tree";
@@ -742,7 +755,8 @@ void Scene_surface_mesh_item::draw(CGAL::Three::Viewer_interface *viewer) const
     }
   
   
-  if(renderingMode() == Gouraud)
+  if(renderingMode() == Gouraud ||
+     renderingMode() == GouraudPlusEdges)
   {
     getTriangleContainer(0)->setColor(color());
     getTriangleContainer(0)->setSelected(is_selected);
@@ -805,7 +819,7 @@ Scene_surface_mesh_item::selection_changed(bool p_is_selected)
 
 bool
 Scene_surface_mesh_item::supportsRenderingMode(RenderingMode m) const
-{ return (m == FlatPlusEdges || m == Wireframe || m == Flat || m == Gouraud || m == Points); }
+{ return d->supported_rendering_modes.contains(m); }
 
 CGAL::Three::Scene_item::Bbox Scene_surface_mesh_item::bbox() const
 {
@@ -2282,36 +2296,40 @@ void Scene_surface_mesh_item::computeItemColorVectorAutomatically(bool b)
   this->setProperty("recompute_colors",b);
 }
 
+void write_in_vbo(Vbo* vbo, cgal_gl_data* data,
+               std::size_t size)
+{
+  vbo->bind();
+  vbo->vbo.write((3*size)*sizeof(cgal_gl_data),
+                 data,
+                 3*sizeof(cgal_gl_data));
+  vbo->release();
+}
+
+//only works on indexed data
 void Scene_surface_mesh_item::updateVertex(vertex_descriptor vh)
 {
-  typedef CGAL::Buffer_for_vao<float, unsigned int> CPF;
-
   const CGAL::qglviewer::Vec offset =
       static_cast<CGAL::Three::Viewer_interface*>(
         CGAL::QGLViewer::QGLViewerPool().first())->offset();
-  //gouraud
   {
     std::size_t id = vh;
-    QOpenGLBuffer *vbo = &(getTriangleContainer(0)->getVbo(Tri::Smooth_vertices)->vbo);
     cgal_gl_data new_point[3];
     Point_3 p = face_graph()->point(vh);
     for(int i=0; i<3; ++i)
       new_point[i]=p[i]+offset[i];
 
+    write_in_vbo(getTriangleContainer(0)->getVbo(Tri::Smooth_vertices),
+                 new_point,
+                 id);
 
-    getTriangleContainer(0)->getVbo(Tri::Smooth_vertices)->bind();
-    vbo->write(static_cast<int>(3*sizeof(cgal_gl_data)*id),new_point,static_cast<int>(3*sizeof(cgal_gl_data)));
-    getTriangleContainer(0)->getVbo(Tri::Smooth_vertices)->release();
+    write_in_vbo(
+          getPointContainer(0)->getVbo(Pt::Vertices),
+          new_point,id);
 
-    vbo =&(getPointContainer(0)->getVbo(Pt::Vertices)->vbo);
-    getPointContainer(0)->getVbo(Pt::Vertices)->bind();
-    vbo->write(static_cast<int>(3*sizeof(cgal_gl_data)*id),new_point,static_cast<int>(3*sizeof(cgal_gl_data)));
-    getPointContainer(0)->getVbo(Pt::Vertices)->release();
-
-    vbo =&(getEdgeContainer(0)->getVbo(Ed::Vertices)->vbo);
-    getEdgeContainer(0)->getVbo(Pt::Vertices)->bind();
-    vbo->write(static_cast<int>(3*sizeof(cgal_gl_data)*id),new_point,static_cast<int>(3*sizeof(cgal_gl_data)));
-    getEdgeContainer(0)->getVbo(Pt::Vertices)->release();
+    write_in_vbo(
+          getEdgeContainer(0)->getVbo(Ed::Vertices),
+          new_point,id);
 
     for(auto v_it : CGAL::vertices_around_target(vh, *face_graph()))
     {
@@ -2319,323 +2337,34 @@ void Scene_surface_mesh_item::updateVertex(vertex_descriptor vh)
       for(int i=0; i<3; ++i)
         new_point[i]=n[i];
       id = v_it;
-      vbo =&(getTriangleContainer(0)->getVbo(Tri::Smooth_normals)->vbo);
-      getTriangleContainer(0)->getVbo(Tri::Smooth_normals)->bind();
-      vbo->write(static_cast<int>(3*sizeof(cgal_gl_data)*id),new_point,static_cast<int>(3*sizeof(cgal_gl_data)));
-      getTriangleContainer(0)->getVbo(Tri::Smooth_normals)->release();
-    }
-  }
-  //flat
-  std::size_t size = 0;
-  if(CGAL::is_triangle_mesh(*face_graph()))
-  {
-    size = 3;
-  }
-  else if (CGAL::is_quad_mesh(*face_graph()))
-  {
-    size = 6;
-  }
-
-  for(auto f : CGAL::faces_around_target(halfedge(vh, *face_graph()), *face_graph()))
-  {
-    if(size == 0)
-    {
-      for(std::size_t i = 0; i < (std::size_t)f; ++i)
-      {
-        size += CGAL::degree(f, *face_graph());
-      }
-    }
-    EPICK::Vector_3 n = CGAL::Polygon_mesh_processing::compute_face_normal(f, *face_graph());
-    cgal_gl_data new_normal[3];
-    for(int i=0; i<3; ++i)
-      new_normal[i]=n[i];
-
-    std::size_t id = f;
-    std::size_t vid = 0;
-
-    if(is_triangle(halfedge(f,*face_graph()),*face_graph()))
-    {
-      for(halfedge_descriptor hd : halfedges_around_face(halfedge(f, *face_graph()),*face_graph()))
-      {
-        Point_3 p = face_graph()->point(source(hd, *face_graph()));
-        cgal_gl_data new_point[3];
-        for(int i=0; i<3; ++i)
-        {
-          new_point[i]=p[i]+offset[i];
-        }
-        QOpenGLBuffer *vbo = &(getTriangleContainer(1)->getVbo(Tri::Flat_normals)->vbo);
-        getTriangleContainer(1)->getVbo(Tri::Flat_normals)->bind();
-        vbo->write(static_cast<int>((3*size*id+vid)*sizeof(cgal_gl_data)),new_normal, static_cast<int>(3*sizeof(cgal_gl_data)));
-        getTriangleContainer(1)->getVbo(Tri::Flat_normals)->release();
-
-        vbo = &(getTriangleContainer(1)->getVbo(Tri::Flat_vertices)->vbo);
-        getTriangleContainer(1)->getVbo(Tri::Flat_vertices)->bind();
-        vbo->write(static_cast<int>((3*size*id+vid)*sizeof(cgal_gl_data)),new_point, static_cast<int>(3*sizeof(cgal_gl_data)));
-        getTriangleContainer(1)->getVbo(Tri::Flat_vertices)->release();
-        vid+=3;
-      }
-    }
-    else
-    {
-      std::vector<Point_3> facet_points;
-      for(halfedge_descriptor hd : halfedges_around_face(halfedge(f, *face_graph()),*face_graph()))
-      {
-        facet_points.push_back(face_graph()->point(target(hd, *face_graph())));
-      }
-      bool is_convex = CPF::is_facet_convex(facet_points, n);
-      if(is_convex && is_quad(halfedge(f,*face_graph()),*face_graph()))
-      {
-        //1st half
-        halfedge_descriptor hd = halfedge(f, *face_graph());
-        Point_3 p = face_graph()->point(source(hd, *face_graph()));
-        cgal_gl_data new_point[3];
-        for(int i=0; i<3; ++i)
-        {
-          new_point[i]=p[i]+offset[i];
-        }
-        QOpenGLBuffer *vbo = &(getTriangleContainer(1)->getVbo(Tri::Flat_normals)->vbo);
-        getTriangleContainer(1)->getVbo(Tri::Flat_normals)->bind();
-        vbo->write(static_cast<int>((3*size*id+vid)*sizeof(cgal_gl_data)),new_normal, static_cast<int>(3*sizeof(cgal_gl_data)));
-        getTriangleContainer(1)->getVbo(Tri::Flat_normals)->release();
-        vbo = &(getTriangleContainer(1)->getVbo(Tri::Flat_vertices)->vbo);
-        getTriangleContainer(1)->getVbo(Tri::Flat_vertices)->bind();
-        vbo->write(static_cast<int>((3*size*id+vid)*sizeof(cgal_gl_data)),new_point, static_cast<int>(3*sizeof(cgal_gl_data)));
-        getTriangleContainer(1)->getVbo(Tri::Flat_vertices)->release();
-        vid+=3;
-
-        hd = next(halfedge(f, *face_graph()),*face_graph());
-        p = face_graph()->point(source(hd, *face_graph()));
-        for(int i=0; i<3; ++i)
-        {
-          new_point[i]=p[i]+offset[i];
-        }
-        vbo = &(getTriangleContainer(1)->getVbo(Tri::Flat_normals)->vbo);
-        getTriangleContainer(1)->getVbo(Tri::Flat_normals)->bind();
-        vbo->write(static_cast<int>((3*size*id+vid)*sizeof(cgal_gl_data)),new_normal, static_cast<int>(3*sizeof(cgal_gl_data)));
-        getTriangleContainer(1)->getVbo(Tri::Flat_normals)->release();
-        vbo = &(getTriangleContainer(1)->getVbo(Tri::Flat_vertices)->vbo);
-        getTriangleContainer(1)->getVbo(Tri::Flat_vertices)->bind();
-        vbo->write(static_cast<int>((3*size*id+vid)*sizeof(cgal_gl_data)),new_point, static_cast<int>(3*sizeof(cgal_gl_data)));
-        getTriangleContainer(1)->getVbo(Tri::Flat_vertices)->release();
-        vid+=3;
-
-        hd = next(next(halfedge(f, *face_graph()),*face_graph()), *face_graph());
-        p = face_graph()->point(source(hd, *face_graph()));
-        for(int i=0; i<3; ++i)
-        {
-          new_point[i]=p[i]+offset[i];
-        }
-        vbo = &(getTriangleContainer(1)->getVbo(Tri::Flat_normals)->vbo);
-        getTriangleContainer(1)->getVbo(Tri::Flat_normals)->bind();
-        vbo->write(static_cast<int>((3*size*id+vid)*sizeof(cgal_gl_data)),new_normal, static_cast<int>(3*sizeof(cgal_gl_data)));
-        getTriangleContainer(1)->getVbo(Tri::Flat_normals)->release();
-        vbo = &(getTriangleContainer(1)->getVbo(Tri::Flat_vertices)->vbo);
-        getTriangleContainer(1)->getVbo(Tri::Flat_vertices)->bind();
-        vbo->write(static_cast<int>((3*size*id+vid)*sizeof(cgal_gl_data)),new_point, static_cast<int>(3*sizeof(cgal_gl_data)));
-        getTriangleContainer(1)->getVbo(Tri::Flat_vertices)->release();
-        vid+=3;
-
-        //2nd half
-        hd = halfedge(f, *face_graph());
-        p = face_graph()->point(source(hd, *face_graph()));
-        for(int i=0; i<3; ++i)
-        {
-          new_point[i]=p[i]+offset[i];
-        }
-        vbo = &(getTriangleContainer(1)->getVbo(Tri::Flat_normals)->vbo);
-        getTriangleContainer(1)->getVbo(Tri::Flat_normals)->bind();
-        vbo->write(static_cast<int>((3*size*id+vid)*sizeof(cgal_gl_data)),new_normal, static_cast<int>(3*sizeof(cgal_gl_data)));
-        getTriangleContainer(1)->getVbo(Tri::Flat_normals)->release();
-        vbo = &(getTriangleContainer(1)->getVbo(Tri::Flat_vertices)->vbo);
-        getTriangleContainer(1)->getVbo(Tri::Flat_vertices)->bind();
-        vbo->write(static_cast<int>((3*size*id+vid)*sizeof(cgal_gl_data)),new_point, static_cast<int>(3*sizeof(cgal_gl_data)));
-        getTriangleContainer(1)->getVbo(Tri::Flat_vertices)->release();
-        vid+=3;
-
-        hd = next(next(halfedge(f, *face_graph()),*face_graph()), *face_graph());
-        p = face_graph()->point(source(hd, *face_graph()));
-        for(int i=0; i<3; ++i)
-        {
-          new_point[i]=p[i]+offset[i];
-        }
-        vbo = &(getTriangleContainer(1)->getVbo(Tri::Flat_normals)->vbo);
-        getTriangleContainer(1)->getVbo(Tri::Flat_normals)->bind();
-        vbo->write(static_cast<int>((3*size*id+vid)*sizeof(cgal_gl_data)),new_normal, static_cast<int>(3*sizeof(cgal_gl_data)));
-        getTriangleContainer(1)->getVbo(Tri::Flat_normals)->release();
-        vbo = &(getTriangleContainer(1)->getVbo(Tri::Flat_vertices)->vbo);
-        getTriangleContainer(1)->getVbo(Tri::Flat_vertices)->bind();
-        vbo->write(static_cast<int>((3*size*id+vid)*sizeof(cgal_gl_data)),new_point, static_cast<int>(3*sizeof(cgal_gl_data)));
-        getTriangleContainer(1)->getVbo(Tri::Flat_vertices)->release();
-        vid+=3;
-
-        hd = prev(halfedge(f, *face_graph()), *face_graph());
-        p = face_graph()->point(source(hd, *face_graph()));
-        for(int i=0; i<3; ++i)
-        {
-          new_point[i]=p[i]+offset[i];
-        }
-        vbo = &(getTriangleContainer(1)->getVbo(Tri::Flat_normals)->vbo);
-        getTriangleContainer(1)->getVbo(Tri::Flat_normals)->bind();
-        vbo->write(static_cast<int>((3*size*id+vid)*sizeof(cgal_gl_data)),new_normal, static_cast<int>(3*sizeof(cgal_gl_data)));
-        getTriangleContainer(1)->getVbo(Tri::Flat_normals)->release();
-        vbo = &(getTriangleContainer(1)->getVbo(Tri::Flat_vertices)->vbo);
-        getTriangleContainer(1)->getVbo(Tri::Flat_vertices)->bind();
-        vbo->write(static_cast<int>((3*size*id+vid)*sizeof(cgal_gl_data)),new_point, static_cast<int>(3*sizeof(cgal_gl_data)));
-        getTriangleContainer(1)->getVbo(Tri::Flat_vertices)->release();
-      }
-      else if(is_convex)
-      {
-        Point_3 p0,p1,p2;
-        SMesh::Halfedge_around_face_circulator he(halfedge(f, *face_graph()), *face_graph());
-        SMesh::Halfedge_around_face_circulator he_end = he;
-
-        while(next(*he, *face_graph()) != prev(*he_end, *face_graph()))
-        {
-          ++he;
-          vertex_descriptor v0(target(*he_end, *face_graph())),
-              v1(target(*he, *face_graph())),
-              v2(target(next(*he, *face_graph()), *face_graph()));
-          p0 = face_graph()->point(v0);
-          p1 = face_graph()->point(v1);
-          p2 = face_graph()->point(v2);
-          cgal_gl_data new_point[3];
-          QOpenGLBuffer *vbo =nullptr;
-          for(int i=0; i<3; ++i)
-          {
-            new_point[i]=p0[i]+offset[i];
-          }
-          vbo = &(getTriangleContainer(1)->getVbo(Tri::Flat_normals)->vbo);
-          getTriangleContainer(1)->getVbo(Tri::Flat_normals)->bind();
-          vbo->write(static_cast<int>((3*size*id+vid)*sizeof(cgal_gl_data)),new_normal, static_cast<int>(3*sizeof(cgal_gl_data)));
-          getTriangleContainer(1)->getVbo(Tri::Flat_normals)->release();
-          vbo = &(getTriangleContainer(1)->getVbo(Tri::Flat_vertices)->vbo);
-          getTriangleContainer(1)->getVbo(Tri::Flat_vertices)->bind();
-          vbo->write(static_cast<int>((3*size*id+vid)*sizeof(cgal_gl_data)),new_point, static_cast<int>(3*sizeof(cgal_gl_data)));
-          getTriangleContainer(1)->getVbo(Tri::Flat_vertices)->release();
-
-          for(int i=0; i<3; ++i)
-          {
-            new_point[i]=p1[i]+offset[i];
-          }
-          vbo = &(getTriangleContainer(1)->getVbo(Tri::Flat_normals)->vbo);
-          getTriangleContainer(1)->getVbo(Tri::Flat_normals)->bind();
-          vbo->write(static_cast<int>((3*size*id+vid)*sizeof(cgal_gl_data)),new_normal, static_cast<int>(3*sizeof(cgal_gl_data)));
-          getTriangleContainer(1)->getVbo(Tri::Flat_normals)->release();
-          vbo = &(getTriangleContainer(1)->getVbo(Tri::Flat_vertices)->vbo);
-          getTriangleContainer(1)->getVbo(Tri::Flat_vertices)->bind();
-          vbo->write(static_cast<int>((3*size*id+vid)*sizeof(cgal_gl_data)),new_point, static_cast<int>(3*sizeof(cgal_gl_data)));
-          getTriangleContainer(1)->getVbo(Tri::Flat_vertices)->release();
-
-          for(int i=0; i<3; ++i)
-          {
-            new_point[i]=p2[i]+offset[i];
-          }
-          vbo = &(getTriangleContainer(1)->getVbo(Tri::Flat_normals)->vbo);
-          getTriangleContainer(1)->getVbo(Tri::Flat_normals)->bind();
-          vbo->write(static_cast<int>((3*size*id+vid)*sizeof(cgal_gl_data)),new_normal, static_cast<int>(3*sizeof(cgal_gl_data)));
-          getTriangleContainer(1)->getVbo(Tri::Flat_normals)->release();
-          vbo = &(getTriangleContainer(1)->getVbo(Tri::Flat_vertices)->vbo);
-          getTriangleContainer(1)->getVbo(Tri::Flat_vertices)->bind();
-          vbo->write(static_cast<int>((3*size*id+vid)*sizeof(cgal_gl_data)),new_point, static_cast<int>(3*sizeof(cgal_gl_data)));
-          getTriangleContainer(1)->getVbo(Tri::Flat_vertices)->release();
-        }
-      }
-      else
-      {
-        //Computes the normal of the facet
-        if(n == CGAL::NULL_VECTOR)
-        {
-          boost::graph_traits<SMesh>::halfedge_descriptor start = prev(halfedge(f, *face_graph()), *face_graph());
-          boost::graph_traits<SMesh>::halfedge_descriptor hd = halfedge(f, *face_graph());
-          boost::graph_traits<SMesh>::halfedge_descriptor next_=next(hd, *face_graph());
-          do
-          {
-            const Point_3& pa = face_graph()->point(target(hd, *face_graph()));
-            const Point_3& pb = face_graph()->point(target(next_, *face_graph()));
-            const Point_3& pc = face_graph()->point(target(prev(hd, *face_graph()), *face_graph()));
-            if (!CGAL::collinear (pa, pb, pc))
-            {
-              n = CGAL::cross_product(pb-pa, pc -pa);
-              break;
-            }
-            next_ =next(next_, *face_graph());
-          }while(next_ != start);
-
-          if (n == CGAL::NULL_VECTOR) // No normal could be computed, return
-          {
-            qDebug()<<"Warning : normal is not valid. Facet not updated";
-            continue;
-          }
-        }
-        //check if normal contains NaN values
-        if (n.x() != n.x() || n.y() != n.y() || n.z() != n.z())
-        {
-          qDebug()<<"Warning : normal is not valid. Facet not displayed";
-          continue;
-        }
-
-        typedef FacetTriangulator<SMesh, EPICK, boost::graph_traits<SMesh>::vertex_descriptor> FT;
-        EPICK::Vector_3 voffset(offset.x,offset.y,offset.z);
-       FT triangulation(f,n,face_graph(), voffset);
-        //iterates on the internal faces
-        for(FT::CDT::Finite_faces_iterator
-            ffit = triangulation.cdt->finite_faces_begin(),
-            end = triangulation.cdt->finite_faces_end();
-            ffit != end; ++ffit)
-        {
-          if(ffit->info().is_external)
-            continue;
-          Point_3 p = ffit->vertex(0)->point();
-          cgal_gl_data new_point[3];
-          for(int i=0; i<3; ++i)
-          {
-            new_point[i]=p[i];
-          }
-          QOpenGLBuffer *vbo = &(getTriangleContainer(1)->getVbo(Tri::Flat_normals)->vbo);
-          getTriangleContainer(1)->getVbo(Tri::Flat_normals)->bind();
-          vbo->write(static_cast<int>((3*size*id+vid)*sizeof(cgal_gl_data)),new_normal, 3*sizeof(cgal_gl_data));
-          getTriangleContainer(1)->getVbo(Tri::Flat_normals)->release();
-          vbo = &(getTriangleContainer(1)->getVbo(Tri::Flat_vertices)->vbo);
-          getTriangleContainer(1)->getVbo(Tri::Flat_vertices)->bind();
-          vbo->write(static_cast<int>((3*size*id+vid)*sizeof(cgal_gl_data)),new_point, 3*sizeof(cgal_gl_data));
-          getTriangleContainer(1)->getVbo(Tri::Flat_vertices)->release();
-          vid+=3;
-
-
-          p = ffit->vertex(1)->point();
-          for(int i=0; i<3; ++i)
-          {
-            new_point[i]=p[i];
-          }
-          vbo = &(getTriangleContainer(1)->getVbo(Tri::Flat_normals)->vbo);
-          getTriangleContainer(1)->getVbo(Tri::Flat_normals)->bind();
-          vbo->write(static_cast<int>((3*size*id+vid)*sizeof(cgal_gl_data)),new_normal, 3*sizeof(cgal_gl_data));
-          getTriangleContainer(1)->getVbo(Tri::Flat_normals)->release();
-          vbo = &(getTriangleContainer(1)->getVbo(Tri::Flat_vertices)->vbo);
-          getTriangleContainer(1)->getVbo(Tri::Flat_vertices)->bind();
-          vbo->write(static_cast<int>((3*size*id+vid)*sizeof(cgal_gl_data)),new_point, 3*sizeof(cgal_gl_data));
-          getTriangleContainer(1)->getVbo(Tri::Flat_vertices)->release();
-          vid+=3;
-
-          p=ffit->vertex(2)->point();
-          for(int i=0; i<3; ++i)
-          {
-            new_point[i]=p[i];
-          }
-          vbo = &(getTriangleContainer(1)->getVbo(Tri::Flat_normals)->vbo);
-          getTriangleContainer(1)->getVbo(Tri::Flat_normals)->bind();
-          vbo->write(static_cast<int>((3*size*id+vid)*sizeof(cgal_gl_data)),new_normal, 3*sizeof(cgal_gl_data));
-          getTriangleContainer(1)->getVbo(Tri::Flat_normals)->release();
-          vbo = &(getTriangleContainer(1)->getVbo(Tri::Flat_vertices)->vbo);
-          getTriangleContainer(1)->getVbo(Tri::Flat_vertices)->bind();
-          vbo->write(static_cast<int>((3*size*id+vid)*sizeof(cgal_gl_data)),new_point, 3*sizeof(cgal_gl_data));
-          getTriangleContainer(1)->getVbo(Tri::Flat_vertices)->release();
-          vid+=3;
-
-        }
-      }
+      write_in_vbo(
+            getTriangleContainer(0)->getVbo(Tri::Smooth_normals),
+            new_point,id);
     }
   }
   invalidate_aabb_tree();
   redraw();
 }
+
+void Scene_surface_mesh_item::switchToGouraudPlusEdge(bool b)
+{
+  if (!b && !d->supported_rendering_modes.contains(Flat))
+  {
+    d->supported_rendering_modes = QList<RenderingMode>() << FlatPlusEdges
+                                                       << Wireframe
+                                                       << Flat
+                                                       << Gouraud
+                                                       << Points;
+    setFlatPlusEdgesMode();
+    invalidateOpenGLBuffers();
+    redraw();
+  }
+  else if(b)
+  {
+    d->supported_rendering_modes = QList<RenderingMode>() << GouraudPlusEdges
+                                                       << Wireframe
+                                                       << Gouraud
+                                                       << Points;
+    setGouraudPlusEdgesMode();
+  }
+}
diff --git a/Polyhedron/demo/Polyhedron/Scene_surface_mesh_item.h b/Polyhedron/demo/Polyhedron/Scene_surface_mesh_item.h
index b36c7c58afc..0306acce865 100644
--- a/Polyhedron/demo/Polyhedron/Scene_surface_mesh_item.h
+++ b/Polyhedron/demo/Polyhedron/Scene_surface_mesh_item.h
@@ -155,7 +155,7 @@ public:
   void computeElements() const Q_DECL_OVERRIDE;
   void initializeBuffers(CGAL::Three::Viewer_interface*)const Q_DECL_OVERRIDE;
   void updateVertex(vertex_descriptor vh);
-
+  void switchToGouraudPlusEdge(bool b); //replace flatPlusEdge by gouraudPlusEdge and ban Flat.
 Q_SIGNALS:
   void item_is_about_to_be_changed();
   void selection_done();
diff --git a/Polyhedron/demo/Polyhedron/Three.cpp b/Polyhedron/demo/Polyhedron/Three.cpp
index 6c7641af2b2..f3e50064776 100644
--- a/Polyhedron/demo/Polyhedron/Three.cpp
+++ b/Polyhedron/demo/Polyhedron/Three.cpp
@@ -201,6 +201,8 @@ QString Three::modeName(RenderingMode mode) {
     return QObject::tr("Gouraud");
   case PointsPlusNormals:
     return QObject::tr("pts+normals");
+  case GouraudPlusEdges:
+    return QObject::tr("gouraud+edges");
   default:
     Q_ASSERT(false);
     return QObject::tr("unknown");
diff --git a/Three/include/CGAL/Three/Scene_interface.h b/Three/include/CGAL/Three/Scene_interface.h
index 71d772a3263..8ec578afe83 100644
--- a/Three/include/CGAL/Three/Scene_interface.h
+++ b/Three/include/CGAL/Three/Scene_interface.h
@@ -41,6 +41,7 @@ enum RenderingMode
   Flat, //!Renders only faces, with a lighting per face.
   FlatPlusEdges, //!Renders flat faces and edges.
   Gouraud, //!Renders only faces, with a lighting per vertex.
+  GouraudPlusEdges, //!Renders faces with a lighting per vertex, and edges.
   ShadedPoints, //!Renders only points with lighting.
   NumberOfRenderingMode //!Number of values in this enum.
 };
diff --git a/Three/include/CGAL/Three/Scene_item.h b/Three/include/CGAL/Three/Scene_item.h
index 8337c9dfbc3..21f8a6c2510 100644
--- a/Three/include/CGAL/Three/Scene_item.h
+++ b/Three/include/CGAL/Three/Scene_item.h
@@ -377,6 +377,10 @@ public Q_SLOTS:
   void setPointsPlusNormalsMode(){
     setRenderingMode(PointsPlusNormals);
   }
+  //!Sets the RenderingMode to GouraudPlusEdges.
+  void setGouraudPlusEdgesMode(){
+    setRenderingMode(GouraudPlusEdges);
+  }
   
   //!Emits an aboutToBeDestroyed() signal.
   //!Override this function to delete what needs to be deleted on destruction.