diff --git a/Polyhedron/demo/Polyhedron/Plugins/IO/CMakeLists.txt b/Polyhedron/demo/Polyhedron/Plugins/IO/CMakeLists.txt
index e5d500cc9db..eff76a7c0d5 100644
--- a/Polyhedron/demo/Polyhedron/Plugins/IO/CMakeLists.txt
+++ b/Polyhedron/demo/Polyhedron/Plugins/IO/CMakeLists.txt
@@ -35,7 +35,7 @@ if (VTK_FOUND)
   if ("${VTK_VERSION_MAJOR}" GREATER "5")
     if(VTK_LIBRARIES)
       polyhedron_demo_plugin(vtk_plugin VTK_io_plugin KEYWORDS IO Mesh_3)
-      target_link_libraries(vtk_plugin PUBLIC scene_surface_mesh_item scene_polylines_item scene_c3t3_item
+      target_link_libraries(vtk_plugin PUBLIC scene_surface_mesh_item scene_polylines_item scene_c3t3_item scene_points_with_normal_item
                                        vtkCommonCore vtkIOCore vtkIOLegacy vtkIOXML
                                        vtkFiltersCore vtkFiltersSources)
 
diff --git a/Polyhedron/demo/Polyhedron/Plugins/IO/VTK_io_plugin.cpp b/Polyhedron/demo/Polyhedron/Plugins/IO/VTK_io_plugin.cpp
index c340b70aa24..30855054d34 100644
--- a/Polyhedron/demo/Polyhedron/Plugins/IO/VTK_io_plugin.cpp
+++ b/Polyhedron/demo/Polyhedron/Plugins/IO/VTK_io_plugin.cpp
@@ -20,11 +20,12 @@
 //
 
 #include <CGAL/Mesh_3/io_signature.h>
-#include "Scene_c3t3_item.h"
 #include <QtCore/qglobal.h>
 
 #include "Scene_surface_mesh_item.h"
+#include "Scene_c3t3_item.h"
 #include "Scene_polylines_item.h"
+#include "Scene_points_with_normal_item.h"
 
 #include <CGAL/Three/Polyhedron_demo_plugin_helper.h>
 #include <CGAL/Three/Polyhedron_demo_io_plugin_interface.h>
@@ -45,6 +46,7 @@
 #include <CGAL/boost/graph/Euler_operations.h>
 #include <CGAL/property_map.h>
 #include <CGAL/IO/Complex_3_in_triangulation_3_to_vtk.h>
+#include <CGAL/Mesh_3/tet_soup_to_c3t3.h>
 #include <CGAL/IO/output_to_vtu.h>
 #include <CGAL/boost/graph/io.h>
 
@@ -161,6 +163,10 @@ namespace CGAL{
     //extract cells
     for (vtkIdType i = 0; i<nb_cells; ++i)
     {
+      if(poly_data->GetCellType(i) != 5
+         && poly_data->GetCellType(i) != 7
+         && poly_data->GetCellType(i) != 9) //only supported cells are triangles, quads and polygons
+        continue;
       vtkCell* cell_ptr = poly_data->GetCell(i);
 
       vtkIdType nb_vertices = cell_ptr->GetNumberOfPoints();
@@ -195,13 +201,17 @@ namespace CGAL{
     //extract segments
     for (vtkIdType i = 0; i<nb_cells; ++i)
     {
+      if(poly_data->GetCellType(i) != 3
+         && poly_data->GetCellType(i) != 4)
+        continue;
       vtkCell* cell_ptr = poly_data->GetCell(i);
 
       vtkIdType nb_vertices = cell_ptr->GetNumberOfPoints();
-      if (nb_vertices !=2) continue;
       segments.push_back( std::vector<Point_3>() );
-      segments.back().push_back(point_map[cell_ptr->GetPointId(0)]);
-      segments.back().push_back(point_map[cell_ptr->GetPointId(1)]);
+      for(int j = 0; j < nb_vertices; ++j)
+      {
+        segments.back().push_back(point_map[cell_ptr->GetPointId(j)]);
+      }
     }
   }
 
@@ -372,17 +382,16 @@ public:
 
     std::string fname = fileinfo.absoluteFilePath().toStdString();
 
-    FaceGraph* poly = new FaceGraph();
     // Try to read .vtk in a facegraph
-    
     if(fileinfo.size() == 0)
     {
       CGAL::Three::Three::warning( tr("The file you are trying to load is empty."));
       Scene_facegraph_item* item =
-          new Scene_facegraph_item(poly);
+          new Scene_facegraph_item();
       item->setName(fileinfo.completeBaseName());
       return item;
     }
+    
     vtkSmartPointer<vtkPointSet> data;
     vtkSmartPointer<CGAL::ErrorObserverVtk> obs =
       vtkSmartPointer<CGAL::ErrorObserverVtk>::New();
@@ -446,24 +455,183 @@ public:
       msgBox.exec();
     }
 
-    if (CGAL::vtkPointSet_to_polygon_mesh(data, *poly))
+    //check celltypes
+    bool is_polygon_mesh(false),
+        is_c3t3(false),
+        is_polyline(false);
+    for(int i = 0; i< data->GetNumberOfCells(); ++i)
     {
-      Scene_facegraph_item* poly_item = new Scene_facegraph_item(poly);
-      poly_item->setName(fileinfo.fileName());
-      return poly_item;
+      int t = data->GetCellType(i);
+      if( t == 5 || t == 7 || t == 9) //tri, quad or polygon
+        is_polygon_mesh = true;
+      else if(t == 10) //tetrahedron
+        is_c3t3 = true;
+      else if( t == 3 || t == 4) //line or polyline
+        is_polyline = true;
     }
-    else{
-      // extract only segments
+    Scene_group_item* group = nullptr;
+    if((is_polygon_mesh && is_c3t3)
+       || (is_polygon_mesh && is_polyline)
+       || (is_c3t3 && is_polyline) )
+    {
+      group = new Scene_group_item(fileinfo.baseName());
+      group->setScene(CGAL::Three::Three::scene());
+    }
+  
+    if(is_polygon_mesh)
+    {
+      FaceGraph* poly = new FaceGraph();
+      if (CGAL::vtkPointSet_to_polygon_mesh(data, *poly))
+      {
+        Scene_facegraph_item* poly_item = new Scene_facegraph_item(poly);
+        if(group)
+        {
+          poly_item->setName(QString("%1_faces").arg(fileinfo.baseName()));
+          CGAL::Three::Three::scene()->addItem(poly_item);
+          CGAL::Three::Three::scene()->changeGroup(poly_item, group);
+        }
+        else{
+          poly_item->setName(fileinfo.baseName());
+          return poly_item;
+        }
+      }
+    }
+    
+    if (is_c3t3)
+    {
+      typedef boost::array<int, 3> Facet; // 3 = id
+      typedef boost::array<int, 5> Tet_with_ref; // first 4 = id, fifth = reference
+      Scene_c3t3_item* c3t3_item = new Scene_c3t3_item();
+      c3t3_item->set_valid(false);
+      //build a triangulation from data:
+      std::vector<Tr::Point> points;
+      vtkPoints* dataP = data->GetPoints();;
+      for(int i = 0; i< data->GetNumberOfPoints(); ++i)
+      {
+        double *p = dataP->GetPoint(i);
+        points.push_back(Tr::Point(p[0],p[1],p[2]));
+      }
+      std::vector<Tet_with_ref> finite_cells;
+      bool has_mesh_domain = data->GetCellData()->HasArray("MeshDomain");
+      vtkDataArray* domains = data->GetCellData()->GetArray("MeshDomain");
+      for(int i = 0; i< data->GetNumberOfCells(); ++i)
+      {
+        if(data->GetCellType(i) != 10 )
+          continue;
+        vtkIdList* pids = data->GetCell(i)->GetPointIds();
+        Tet_with_ref cell;
+        for(int j = 0; j<4; ++j)
+          cell[j] = pids->GetId(j);
+        cell[4] = has_mesh_domain ? static_cast<int>(domains->GetComponent(i,0))
+                                  :1;
+        finite_cells.push_back(cell);
+      }
+      std::map<Facet, int> border_facets;
+      //Preprocessing for build_triangulation
+      //check for orientation and swap in cells if not good.
+      for(std::size_t i=0; i<finite_cells.size(); ++i)
+      {
+        Point_3 test_points[4];
+        for (int j = 0; j < 4; ++j)
+        {
+          Tr::Point tp = points[finite_cells[i][j]];
+          test_points[j] = Point_3(tp.x(), tp.y(), tp.z());
+        }
+        if(CGAL::orientation(test_points[0], test_points[1], test_points[2], test_points[3])
+                             != CGAL::POSITIVE)
+        {
+          std::swap(finite_cells[i][1], finite_cells[i][3]);
+        }
+      }
+      CGAL::build_triangulation<Tr, true>(c3t3_item->c3t3().triangulation(), points, finite_cells, border_facets);
+      
+      for( C3t3::Triangulation::Finite_cells_iterator
+           cit = c3t3_item->c3t3().triangulation().finite_cells_begin();
+           cit != c3t3_item->c3t3().triangulation().finite_cells_end();
+           ++cit)
+      {
+        CGAL_assertion(cit->info() >= 0);
+        c3t3_item->c3t3().add_to_complex(cit, cit->info());
+        for(int i=0; i < 4; ++i)
+        {
+          if(cit->surface_patch_index(i)>0)
+          {
+            c3t3_item->c3t3().add_to_complex(cit, i, cit->surface_patch_index(i));
+          }
+        }
+      }
+      
+      //if there is no facet in the complex, we add the border facets.
+      if(c3t3_item->c3t3().number_of_facets_in_complex() == 0)
+      {
+        for( C3t3::Triangulation::Finite_facets_iterator
+             fit = c3t3_item->c3t3().triangulation().finite_facets_begin();
+             fit != c3t3_item->c3t3().triangulation().finite_facets_end();
+             ++fit)
+        {
+          typedef C3t3::Triangulation::Cell_handle      Cell_handle;
+          
+          Cell_handle c = fit->first;
+          Cell_handle nc = c->neighbor(fit->second);
+          
+          // By definition, Subdomain_index() is supposed to be the id of the exterior
+          if(c->subdomain_index() != C3t3::Triangulation::Cell::Subdomain_index() &&
+             nc->subdomain_index() == C3t3::Triangulation::Cell::Subdomain_index())
+          {
+            // Color the border facet with the index of its cell
+            c3t3_item->c3t3().add_to_complex(c, fit->second, c->subdomain_index());
+          }
+        }
+      }
+      c3t3_item->c3t3_changed();
+      c3t3_item->resetCutPlane();
+      if(group)
+      {
+        c3t3_item->setName(QString("%1_tetrahedra").arg(fileinfo.baseName()));
+        CGAL::Three::Three::scene()->addItem(c3t3_item);
+        CGAL::Three::Three::scene()->changeGroup(c3t3_item, group);
+      }
+      else{
+        c3t3_item->setName(fileinfo.baseName());
+        return c3t3_item;
+      }
+    }
+    
+    if(is_polyline)
+    {
       std::vector< std::vector<Point> > segments;
       extract_segments_from_vtkPointSet(data,segments);
-      if (segments.empty()) return NULL; /// TODO handle point sets
       Scene_polylines_item* polyline_item = new Scene_polylines_item();
-      polyline_item->setName(fileinfo.fileName());
       BOOST_FOREACH(const std::vector<Point>& segment, segments)
-        polyline_item->polylines.push_back(segment);
-      return polyline_item;
+          polyline_item->polylines.push_back(segment);
+      if(group)
+      {
+        polyline_item->setName(QString("%1_lines").arg(fileinfo.baseName()));
+        CGAL::Three::Three::scene()->addItem(polyline_item);
+        CGAL::Three::Three::scene()->changeGroup(polyline_item, group);
+      }
+      else{
+        polyline_item->setName(fileinfo.baseName());
+        return polyline_item;
+      }
     }
-    return NULL;
+    
+    if(group)
+      return group;
+    
+    QApplication::restoreOverrideCursor();
+    QMessageBox::warning(CGAL::Three::Three::mainWindow(),
+                         "Problematic file",
+                         "Cell type not recognized. Only points will be displayed.");
+    QApplication::setOverrideCursor(Qt::WaitCursor);
+    Scene_points_with_normal_item* point_item = new Scene_points_with_normal_item();
+    for(int i=0; i< data->GetNumberOfPoints(); ++i)
+    {
+      double* p = data->GetPoint(i);
+      point_item->point_set()->insert(Point_3(p[0], p[1], p[2]));
+    }
+    point_item->setName(fileinfo.baseName());
+    return point_item;
   }
 }; // end Polyhedron_demo_vtk_plugin
 
diff --git a/Polyhedron/demo/Polyhedron/Scene.cpp b/Polyhedron/demo/Polyhedron/Scene.cpp
index 38956320395..7994c82d144 100644
--- a/Polyhedron/demo/Polyhedron/Scene.cpp
+++ b/Polyhedron/demo/Polyhedron/Scene.cpp
@@ -98,16 +98,15 @@ Scene::replaceItem(Scene::Item_id index, CGAL::Three::Scene_item* item, bool emi
             this, SLOT(callDraw()));
     CGAL::Three::Scene_group_item* group =
             qobject_cast<CGAL::Three::Scene_group_item*>(m_entries[index]);
+    QList<Scene_item*> group_children;
     if(group)
     {
-      QList<int> group_children;
       Q_FOREACH(Item_id id, group->getChildren())
       {
         CGAL::Three::Scene_item* child = group->getChild(id);
         group->unlockChild(child);
-        group_children << item_id(child);
+        group_children << child;
       }
-      erase(group_children);
     }
     CGAL::Three::Scene_group_item* parent = m_entries[index]->parentGroup();
     bool is_locked = false;
@@ -148,6 +147,10 @@ Scene::replaceItem(Scene::Item_id index, CGAL::Three::Scene_item* item, bool emi
     Q_EMIT restoreCollapsedState();
     redraw_model();
     Q_EMIT selectionChanged(index);
+    Q_FOREACH(Scene_item* child, group_children)
+    {
+      erase(item_id(child));
+    }
     return item;
 }
 
@@ -1013,10 +1016,13 @@ Scene::setData(const QModelIndex &index,
     {
         RenderingMode rendering_mode = static_cast<RenderingMode>(value.toInt());
         // Find next supported rendering mode
+        int counter = 0;
         while ( ! item->supportsRenderingMode(rendering_mode)
                 )
         {
             rendering_mode = static_cast<RenderingMode>( (rendering_mode+1) % NumberOfRenderingMode );
+            if(counter++ == NumberOfRenderingMode)
+              break;
         }
         item->setRenderingMode(rendering_mode);
         QModelIndex nindex = createIndex(m_entries.size()-1,RenderingModeColumn+1);