diff --git a/Polyhedron/demo/Polyhedron/MainWindow.cpp b/Polyhedron/demo/Polyhedron/MainWindow.cpp
index 6866f6ef032..04c8b559808 100644
--- a/Polyhedron/demo/Polyhedron/MainWindow.cpp
+++ b/Polyhedron/demo/Polyhedron/MainWindow.cpp
@@ -371,6 +371,7 @@ MainWindow::MainWindow(const QStringList &keywords, bool verbose, QWidget* paren
 
   // Setup the submenu of the View menu that can toggle the dockwidgets
   Q_FOREACH(QDockWidget* widget, findChildren<QDockWidget*>()) {
+    widget->setFeatures(QDockWidget::DockWidgetClosable | QDockWidget::DockWidgetFloatable);
     ui->menuDockWindows->addAction(widget->toggleViewAction());
   }
   ui->menuDockWindows->removeAction(ui->dummyAction);
@@ -1285,7 +1286,7 @@ QList<Scene_item*> MainWindow::loadItem(QFileInfo fileinfo,
   QCursor tmp_cursor(Qt::WaitCursor);
   CGAL::Three::Three::CursorScopeGuard guard(tmp_cursor);
   QList<Scene_item*> result = loader->load(fileinfo, ok, add_to_scene);
-  if(result.empty() || !ok)
+  if(!ok)
   {
     QApplication::restoreOverrideCursor();
       QMessageBox::warning(this, tr("Error"),
@@ -1579,6 +1580,8 @@ void MainWindow::showSceneContextMenu(const QPoint& p) {
             has_stats = true;
         }
         QMenu menu;
+        menu.addAction(actionAddToGroup);
+        menu.insertSeparator(0);
         Q_FOREACH(QString name, menu_actions.keys())
         {
           if(name == QString("alpha slider")
@@ -2579,6 +2582,10 @@ void MainWindow::makeNewGroup()
 {
   Scene_group_item * group = new Scene_group_item();
   scene->addItem(group);
+  for(Scene::Item_id id : scene->selectionIndices())
+  {
+    scene->changeGroup(scene->item(id), group);
+  }
 }
 
 void MainWindow::on_upButton_pressed()
@@ -2956,6 +2963,7 @@ void MainWindow::on_actionSa_ve_Scene_as_Script_triggered()
   std::vector<QColor> colors;
   std::vector<int> rendering_modes;
   QStringList not_saved;
+  Polyhedron_demo_io_plugin_interface* camera_plugin = nullptr;
   for(int i = 0; i < scene->numberOfEntries(); ++i)
   {
     Scene_item* item = scene->item(i);
@@ -2963,6 +2971,8 @@ void MainWindow::on_actionSa_ve_Scene_as_Script_triggered()
     QString ext;
     for(Polyhedron_demo_io_plugin_interface* iop : io_plugins)
     {
+      if(iop->name() == "camera_positions_plugin")
+        camera_plugin = iop;
       if(iop->isDefaultLoader(item))
       {
         QString sf = iop->saveNameFilters().split(";;").first();
@@ -2992,6 +3002,23 @@ void MainWindow::on_actionSa_ve_Scene_as_Script_triggered()
     colors.push_back(item->color());
     rendering_modes.push_back(item->renderingMode());
   }
+  bool has_camera_positions = false;
+  if(camera_plugin)
+  {
+    QString fullpath = make_fullpath("camera_tmp.camera.txt");
+    QList<Scene_item*> dummy;
+    if(camera_plugin->save(QFileInfo(fullpath), dummy))
+    {
+      QByteArray item = file_to_string(fullpath.toStdString().c_str());
+      os << "var camera_positions= [\'";
+      os<<qCompress(item, 9).toBase64().toStdString().c_str();
+      os << "\']\n" ;
+      //delete temp file
+      QFile tmp_file(fullpath);
+      tmp_file.remove();
+      has_camera_positions =true;
+    }
+  }
   if(loaders.empty())
     return;
   //path
@@ -3054,6 +3081,12 @@ void MainWindow::on_actionSa_ve_Scene_as_Script_triggered()
   os << "        it.setRenderingMode(rendering_modes[index]);\n";
   os << "});\n";
   os << "viewer.moveCameraToCoordinates(camera, 0.05);\n";
+  if(has_camera_positions)
+  {
+    os<<"  var path=\"cams.camera.txt\";\n";
+    os<<"  var fullpath = main_window.write_string_to_file(camera_positions, path);\n";
+    os<<"  main_window.open(fullpath,\'camera_positions_plugin\');\n";
+  }
   os.close();
   if(!not_saved.empty())
     QMessageBox::warning(this,
@@ -3238,6 +3271,13 @@ void MainWindow::setupViewer(Viewer* viewer, SubViewer* subviewer)
     }
     viewer->setTotalPass(nb);
   });
+
+  action = subviewer->findChild<QAction*>("actionScaleScene");
+  action->setCheckable(true);
+  action->setChecked(false);
+  connect(action, &QAction::triggered,
+          viewer, &Viewer::scaleScene);
+
   action= subviewer->findChild<QAction*>("actionBackFrontShading");
   connect(action, SIGNAL(toggled(bool)),
           viewer, SLOT(setBackFrontShading(bool)));
@@ -3450,6 +3490,10 @@ SubViewer::SubViewer(QWidget *parent, MainWindow* mw, Viewer* mainviewer)
   actionBackFrontShading->setChecked(false);
   viewMenu->addAction(actionBackFrontShading);
 
+  QAction* actionScaleScene = new QAction("&Scale the Scene...",this);
+  actionScaleScene->setObjectName("actionScaleScene");
+  viewMenu->addAction(actionScaleScene);
+
   if(mainviewer)
     setAttribute(Qt::WA_DeleteOnClose);
   setWindowIcon(QIcon(":/cgal/icons/resources/menu.png"));
diff --git a/Polyhedron/demo/Polyhedron/Plugins/Camera_position/Camera_positions_list.cpp b/Polyhedron/demo/Polyhedron/Plugins/Camera_position/Camera_positions_list.cpp
index 707a5b7fff3..c015e8f495c 100644
--- a/Polyhedron/demo/Polyhedron/Plugins/Camera_position/Camera_positions_list.cpp
+++ b/Polyhedron/demo/Polyhedron/Plugins/Camera_position/Camera_positions_list.cpp
@@ -89,13 +89,9 @@ void Camera_positions_list::activatedRow(QModelIndex index)
   Three::activeViewer()->moveCameraToCoordinates(s);
 }
 
-void Camera_positions_list::on_saveButton_pressed()
-{
-  QString filename =
-    QFileDialog::getSaveFileName(this,
-                                 tr("Save camera coordinates to file"),
-                                 QString(),
-                                 tr("(*.camera.txt)"));
+bool Camera_positions_list::save(QString filename) {
+  if(m_model->rowCount() <1)
+    return false;
   QFile file(filename);
   file.open(QIODevice::WriteOnly);
   QTextStream out(&file);
@@ -108,6 +104,17 @@ void Camera_positions_list::on_saveButton_pressed()
         << "\n";
   }
   file.close();
+  return true;
+}
+
+void Camera_positions_list::on_saveButton_pressed()
+{
+  QString filename =
+    QFileDialog::getSaveFileName(this,
+                                 tr("Save camera coordinates to file"),
+                                 QString(),
+                                 tr("(*.camera.txt)"));
+  save(filename);
 }
 
 void Camera_positions_list::on_openButton_pressed()
diff --git a/Polyhedron/demo/Polyhedron/Plugins/Camera_position/Camera_positions_list.h b/Polyhedron/demo/Polyhedron/Plugins/Camera_position/Camera_positions_list.h
index 575fd68b603..f9d43a2a88d 100644
--- a/Polyhedron/demo/Polyhedron/Plugins/Camera_position/Camera_positions_list.h
+++ b/Polyhedron/demo/Polyhedron/Plugins/Camera_position/Camera_positions_list.h
@@ -15,6 +15,7 @@ public:
 
 public Q_SLOTS:
   void load(QString filename);
+  bool save(QString filename);
 protected Q_SLOTS:
   void on_plusButton_pressed();
   void on_minusButton_pressed();
@@ -41,3 +42,4 @@ private:
 };
 
 #endif
+
diff --git a/Polyhedron/demo/Polyhedron/Plugins/Camera_position/Camera_positions_plugin.cpp b/Polyhedron/demo/Polyhedron/Plugins/Camera_position/Camera_positions_plugin.cpp
index e252689a452..53104cf7256 100644
--- a/Polyhedron/demo/Polyhedron/Plugins/Camera_position/Camera_positions_plugin.cpp
+++ b/Polyhedron/demo/Polyhedron/Plugins/Camera_position/Camera_positions_plugin.cpp
@@ -31,8 +31,11 @@ public:
     return QList<Scene_item*>();
   }
 
-  bool canSave(const Scene_item*) override { return false; }
-  bool save(QFileInfo,QList<CGAL::Three::Scene_item*>& ) override {return false; }
+  bool canSave(const Scene_item*) override { return true; }
+  bool save(QFileInfo fileinfo,QList<CGAL::Three::Scene_item*>& ) override
+  {
+    return cpl->save(fileinfo.filePath());
+  }
 private:
   Camera_positions_list* cpl;
 };
diff --git a/Polyhedron/demo/Polyhedron/Plugins/PMP/CMakeLists.txt b/Polyhedron/demo/Polyhedron/Plugins/PMP/CMakeLists.txt
index d4392625bca..a7d9eac607b 100644
--- a/Polyhedron/demo/Polyhedron/Plugins/PMP/CMakeLists.txt
+++ b/Polyhedron/demo/Polyhedron/Plugins/PMP/CMakeLists.txt
@@ -95,7 +95,7 @@ target_link_libraries(surface_intersection_plugin PUBLIC scene_surface_mesh_item
 
 qt5_wrap_ui( repairUI_FILES RemoveNeedlesDialog.ui)
 polyhedron_demo_plugin(repair_polyhedron_plugin Repair_polyhedron_plugin  ${repairUI_FILES} KEYWORDS PMP)
-target_link_libraries(repair_polyhedron_plugin PUBLIC scene_surface_mesh_item)
+target_link_libraries(repair_polyhedron_plugin PUBLIC scene_points_with_normal_item scene_surface_mesh_item)
 
 qt5_wrap_ui( isotropicRemeshingUI_FILES Isotropic_remeshing_dialog.ui)
 polyhedron_demo_plugin(isotropic_remeshing_plugin Isotropic_remeshing_plugin  ${isotropicRemeshingUI_FILES} KEYWORDS PMP)
diff --git a/Polyhedron/demo/Polyhedron/Plugins/PMP/Repair_polyhedron_plugin.cpp b/Polyhedron/demo/Polyhedron/Plugins/PMP/Repair_polyhedron_plugin.cpp
index 0e50beabcf1..f16ad282266 100644
--- a/Polyhedron/demo/Polyhedron/Plugins/PMP/Repair_polyhedron_plugin.cpp
+++ b/Polyhedron/demo/Polyhedron/Plugins/PMP/Repair_polyhedron_plugin.cpp
@@ -1,6 +1,7 @@
 #include <QtCore/qglobal.h>
 
 #include "Scene_surface_mesh_item.h"
+#include "Scene_points_with_normal_item.h"
 #include <CGAL/Three/Scene_interface.h>
 #include <CGAL/Three/Polyhedron_demo_plugin_interface.h>
 #include <CGAL/Three/Polyhedron_demo_plugin_helper.h>
@@ -47,6 +48,7 @@ public:
     actionRemoveSelfIntersections = new QAction(tr("Remove Self-Intersections"), mw);
     actionStitchCloseBorderHalfedges = new QAction(tr("Stitch Close Border Halfedges"), mw);
     actionDuplicateNMVertices = new QAction(tr("Duplicate Non-Manifold Vertices"), mw);
+    actionExtractNMVertices = new QAction(tr("Extract Non-Manifold Vertices"), mw);
     actionMergeDuplicatedVerticesOnBoundaryCycles = new QAction(tr("Merge Duplicated Vertices on Boundary Cycles"), mw);
     actionAutorefine = new QAction(tr("Autorefine Mesh"), mw);
     actionAutorefineAndRMSelfIntersections = new QAction(tr("Autorefine and Remove Self-Intersections"), mw);
@@ -57,6 +59,7 @@ public:
     actionRemoveSelfIntersections->setObjectName("actionRemoveSelfIntersections");
     actionStitchCloseBorderHalfedges->setObjectName("actionStitchCloseBorderHalfedges");
     actionDuplicateNMVertices->setObjectName("actionDuplicateNMVertices");
+    actionExtractNMVertices->setObjectName("actionExtractNMVertices");
     actionMergeDuplicatedVerticesOnBoundaryCycles->setObjectName("actionMergeDuplicatedVerticesOnBoundaryCycles");
     actionAutorefine->setObjectName("actionAutorefine");
     actionAutorefineAndRMSelfIntersections->setObjectName("actionAutorefineAndRMSelfIntersections");
@@ -67,6 +70,7 @@ public:
     actionRemoveSelfIntersections->setProperty("subMenuName", "Polygon Mesh Processing/Repair/Experimental");
     actionRemoveIsolatedVertices->setProperty("subMenuName", "Polygon Mesh Processing/Repair");
     actionDuplicateNMVertices->setProperty("subMenuName", "Polygon Mesh Processing/Repair");
+    actionExtractNMVertices->setProperty("subMenuName", "Polygon Mesh Processing/Repair");
     actionMergeDuplicatedVerticesOnBoundaryCycles->setProperty("subMenuName", "Polygon Mesh Processing/Repair");
     actionAutorefine->setProperty("subMenuName", "Polygon Mesh Processing/Repair/Experimental");
     actionAutorefineAndRMSelfIntersections->setProperty("subMenuName", "Polygon Mesh Processing/Repair/Experimental");
@@ -82,6 +86,7 @@ public:
                              << actionRemoveSelfIntersections
                              << actionStitchCloseBorderHalfedges
                              << actionDuplicateNMVertices
+                             << actionExtractNMVertices
                              << actionMergeDuplicatedVerticesOnBoundaryCycles
                              << actionAutorefine
                              << actionAutorefineAndRMSelfIntersections
@@ -104,6 +109,8 @@ public:
   template <typename Item>
   void on_actionDuplicateNMVertices_triggered(Scene_interface::Item_id index);
   template <typename Item>
+  void on_actionExtractNMVertices_triggered(Scene_interface::Item_id index);
+  template <typename Item>
   void on_actionMergeDuplicatedVerticesOnBoundaryCycles_triggered(Scene_interface::Item_id index);
   template <typename Item>
   void on_actionAutorefine_triggered(Scene_interface::Item_id index);
@@ -116,6 +123,7 @@ public Q_SLOTS:
   void on_actionRemoveSelfIntersections_triggered();
   void on_actionStitchCloseBorderHalfedges_triggered();
   void on_actionDuplicateNMVertices_triggered();
+  void on_actionExtractNMVertices_triggered();
   void on_actionMergeDuplicatedVerticesOnBoundaryCycles_triggered();
   void on_actionAutorefine_triggered();
   void on_actionAutorefineAndRMSelfIntersections_triggered();
@@ -127,6 +135,7 @@ private:
   QAction* actionRemoveSelfIntersections;
   QAction* actionStitchCloseBorderHalfedges;
   QAction* actionDuplicateNMVertices;
+  QAction* actionExtractNMVertices;
   QAction* actionMergeDuplicatedVerticesOnBoundaryCycles;
   QAction* actionAutorefine;
   QAction* actionAutorefineAndRMSelfIntersections;
@@ -347,6 +356,32 @@ void Polyhedron_demo_repair_polyhedron_plugin::on_actionDuplicateNMVertices_trig
   }
 }
 
+template <typename Item>
+void Polyhedron_demo_repair_polyhedron_plugin::on_actionExtractNMVertices_triggered(Scene_interface::Item_id index)
+{
+  namespace PMP =   CGAL::Polygon_mesh_processing;
+  typedef typename boost::graph_traits<typename Item::Face_graph>::halfedge_descriptor halfedge_descriptor;
+
+  if (Item* poly_item = qobject_cast<Item*>(scene->item(index)))
+  {
+    std::vector<halfedge_descriptor> hds;
+    PMP::non_manifold_vertices(*poly_item->face_graph(), std::back_inserter(hds));
+    if(hds.empty())
+    {
+      CGAL::Three::Three::information(tr(" No NM vertex found."));
+      return;
+    }
+    Scene_points_with_normal_item* pitem = new Scene_points_with_normal_item();
+    pitem->setColor(Qt::red);
+    pitem->setName(QString("%1 nm vertices").arg(poly_item->name()));
+    for(const auto& h : hds)
+    {
+      pitem->point_set()->insert(poly_item->face_graph()->point(target(h, *poly_item->face_graph())));
+    }
+    scene->addItem (pitem);
+  }
+}
+
 void Polyhedron_demo_repair_polyhedron_plugin::on_actionDuplicateNMVertices_triggered()
 {
   QApplication::setOverrideCursor(Qt::WaitCursor);
@@ -355,6 +390,14 @@ void Polyhedron_demo_repair_polyhedron_plugin::on_actionDuplicateNMVertices_trig
   QApplication::restoreOverrideCursor();
 }
 
+void Polyhedron_demo_repair_polyhedron_plugin::on_actionExtractNMVertices_triggered()
+{
+  QApplication::setOverrideCursor(Qt::WaitCursor);
+  const Scene_interface::Item_id index = scene->mainSelectionIndex();
+  on_actionExtractNMVertices_triggered<Scene_surface_mesh_item>(index);
+  QApplication::restoreOverrideCursor();
+}
+
 template <typename Item>
 void Polyhedron_demo_repair_polyhedron_plugin::on_actionMergeDuplicatedVerticesOnBoundaryCycles_triggered(Scene_interface::Item_id index)
 {
diff --git a/Polyhedron/demo/Polyhedron/Polyhedron_demo_plugin_helper.cpp b/Polyhedron/demo/Polyhedron/Polyhedron_demo_plugin_helper.cpp
index 0418d405f72..51a425f57f0 100644
--- a/Polyhedron/demo/Polyhedron/Polyhedron_demo_plugin_helper.cpp
+++ b/Polyhedron/demo/Polyhedron/Polyhedron_demo_plugin_helper.cpp
@@ -9,7 +9,7 @@ void CGAL::Three::Polyhedron_demo_plugin_helper::addDockWidget(QDockWidget* dock
 {
   mw->addDockWidget(::Qt::LeftDockWidgetArea, dock_widget);
   dock_widget->setSizePolicy(QSizePolicy(QSizePolicy::Preferred, QSizePolicy::Preferred));
-
+  dock_widget->setFeatures(QDockWidget::DockWidgetClosable | QDockWidget::DockWidgetFloatable);
   QList<QDockWidget*> dockWidgets = mw->findChildren<QDockWidget*>();
   int counter = 0;
   Q_FOREACH(QDockWidget* dock, dockWidgets) {
diff --git a/Polyhedron/demo/Polyhedron/Scene.cpp b/Polyhedron/demo/Polyhedron/Scene.cpp
index 8ea8f34d521..6ddc13cc074 100644
--- a/Polyhedron/demo/Polyhedron/Scene.cpp
+++ b/Polyhedron/demo/Polyhedron/Scene.cpp
@@ -90,6 +90,8 @@ Scene::addItem(CGAL::Three::Scene_item* item)
     item->drawEdges(CGAL::Three::Three::mainViewer());
     item->drawPoints(CGAL::Three::Three::mainViewer());
     CGAL::Three::Three::mainViewer()->setDepthPeelingFbo(fbo);
+    if(group)
+       m_groups.append(id);
     return id;
 }
 
@@ -110,6 +112,7 @@ Scene::replaceItem(Scene::Item_id index, CGAL::Three::Scene_item* item, bool emi
     QList<Scene_item*> group_children;
     if(group)
     {
+      m_groups.removeAll(index);
       Q_FOREACH(Item_id id, group->getChildren())
       {
         CGAL::Three::Scene_item* child = group->getChild(id);
@@ -152,6 +155,7 @@ Scene::replaceItem(Scene::Item_id index, CGAL::Three::Scene_item* item, bool emi
     if(group)
     {
         addGroup(group);
+        m_groups.append(index);
     }
     itemChanged(index);
     Q_EMIT restoreCollapsedState();
@@ -173,6 +177,7 @@ Scene::erase(Scene::Item_id index)
     setSelectedItemsList(QList<Scene_interface::Item_id>()<<item_id(item));
     return erase(selectionIndices());
   }
+  m_groups.removeAll(index);
   if(item->parentGroup()
      && item->parentGroup()->isChildLocked(item))
     return -1;
@@ -248,6 +253,7 @@ Scene::erase(QList<int> indices)
       item->parentGroup()->removeChild(item);
     children.removeAll(removed_item);
     indexErased(removed_item);
+    m_groups.removeAll(removed_item);
     m_entries.removeAll(item);
 
     Q_EMIT itemAboutToBeDestroyed(item);
@@ -1359,9 +1365,15 @@ QItemSelection Scene::createSelectionAll()
   //it is not possible to directly create a selection with items that have different parents, so
   //we do it iteratively.
   QItemSelection sel;
-  for(int i=0; i< m_entries.size(); ++i)
-    sel.select(index_map.keys(i).at(0),
-               index_map.keys(i).at(4));
+  sel.select(this->createIndex(0, 0),
+             this->createIndex(m_entries.size(), LastColumn));
+  for(const auto& gid : m_groups)
+  {
+    CGAL::Three::Scene_group_item* group =
+        qobject_cast<CGAL::Three::Scene_group_item*>(item(gid));
+    sel.select(index_map.keys(group->getChildren().first()).at(0),
+               index_map.keys(group->getChildren().last()).at(4));
+  }
   return sel;
 }
 
@@ -1726,7 +1738,7 @@ void Scene::updatePrimitiveIds(CGAL::Three::Scene_item* it)
     }
   }
 }
-bool Scene::testDisplayId(double x, double y, double z, CGAL::Three::Viewer_interface* viewer)
+bool Scene::testDisplayId(double x, double y, double z, CGAL::Three::Viewer_interface* viewer, const QVector3D& scaler)
 {
     CGAL::Three::Scene_item *i = item(mainSelectionIndex());
     if(!i)
@@ -1734,7 +1746,7 @@ bool Scene::testDisplayId(double x, double y, double z, CGAL::Three::Viewer_inte
     Scene_print_item_interface* spit= qobject_cast<Scene_print_item_interface*>(i);
     if(spit && i->visible())
     {
-        bool res = spit->testDisplayId(x,y,z, viewer);
+        bool res = spit->testDisplayId(x,y,z, viewer, scaler);
         return res;
     }
     else
diff --git a/Polyhedron/demo/Polyhedron/Scene.h b/Polyhedron/demo/Polyhedron/Scene.h
index 6240a255abf..1159739e3e7 100644
--- a/Polyhedron/demo/Polyhedron/Scene.h
+++ b/Polyhedron/demo/Polyhedron/Scene.h
@@ -64,6 +64,7 @@ public:
   int numberOfEntries() const Q_DECL_OVERRIDE;
   // returns the list of items.
   const QList<CGAL::Three::Scene_item*>& entries() const { return m_entries; }
+
   Q_INVOKABLE CGAL::Three::Scene_item* item(int) const Q_DECL_OVERRIDE;
   int item_id(CGAL::Three::Scene_item*) const Q_DECL_OVERRIDE;
 
@@ -94,7 +95,7 @@ public:
   void printAllIds() Q_DECL_OVERRIDE;
   //!Re-computes the primitiveIds for `item`
   void updatePrimitiveIds(Scene_item *item) Q_DECL_OVERRIDE;
-  bool testDisplayId(double x, double y, double z, CGAL::Three::Viewer_interface* viewer) Q_DECL_OVERRIDE;
+  bool testDisplayId(double x, double y, double z, CGAL::Three::Viewer_interface* viewer, const QVector3D& scaler) Q_DECL_OVERRIDE;
   Bbox bbox() const Q_DECL_OVERRIDE;
   void computeBbox();
   double len_diagonal() const Q_DECL_OVERRIDE
@@ -280,6 +281,7 @@ private:
   typedef QList<CGAL::Three::Scene_item*> Entries;
   //List containing all the scene_items.
   Entries m_entries;
+  QList<Item_id> m_groups; //used to optimize createSelectionAll()
   QList<Item_id> children;
   // Index of the currently selected item.
   int selected_item;
diff --git a/Polyhedron/demo/Polyhedron/Scene_polyhedron_selection_item.cpp b/Polyhedron/demo/Polyhedron/Scene_polyhedron_selection_item.cpp
index 2473c474f3c..69de06f2d58 100644
--- a/Polyhedron/demo/Polyhedron/Scene_polyhedron_selection_item.cpp
+++ b/Polyhedron/demo/Polyhedron/Scene_polyhedron_selection_item.cpp
@@ -2254,9 +2254,9 @@ void Scene_polyhedron_selection_item::printAllIds()
 {
   d->item->polyhedron_item()->printAllIds();
 }
-bool Scene_polyhedron_selection_item::testDisplayId(double x, double y, double z, CGAL::Three::Viewer_interface* viewer)const
+bool Scene_polyhedron_selection_item::testDisplayId(double x, double y, double z, CGAL::Three::Viewer_interface* viewer, const QVector3D& scaler)const
 {
-  return d->item->polyhedron_item()->testDisplayId(x, y, z, viewer);
+  return d->item->polyhedron_item()->testDisplayId(x, y, z, viewer, scaler);
   return false;
 }
 
diff --git a/Polyhedron/demo/Polyhedron/Scene_polyhedron_selection_item.h b/Polyhedron/demo/Polyhedron/Scene_polyhedron_selection_item.h
index dbfca601296..71cd28e6f85 100644
--- a/Polyhedron/demo/Polyhedron/Scene_polyhedron_selection_item.h
+++ b/Polyhedron/demo/Polyhedron/Scene_polyhedron_selection_item.h
@@ -218,7 +218,7 @@ public:
   bool printEdgeIds() const;
   bool printFaceIds() const;
   void printAllIds();
-  bool testDisplayId(double, double, double, CGAL::Three::Viewer_interface*)const;
+  bool testDisplayId(double, double, double, CGAL::Three::Viewer_interface*, const QVector3D&)const;
   bool shouldDisplayIds(CGAL::Three::Scene_item *current_item) const;
   QString defaultSaveName() const
   {
diff --git a/Polyhedron/demo/Polyhedron/Scene_surface_mesh_item.cpp b/Polyhedron/demo/Polyhedron/Scene_surface_mesh_item.cpp
index ee404035f3f..3addac4c486 100644
--- a/Polyhedron/demo/Polyhedron/Scene_surface_mesh_item.cpp
+++ b/Polyhedron/demo/Polyhedron/Scene_surface_mesh_item.cpp
@@ -2130,7 +2130,7 @@ void Scene_surface_mesh_item::printAllIds()
   d->killIds();
 }
 
-bool Scene_surface_mesh_item::testDisplayId(double x, double y, double z, CGAL::Three::Viewer_interface* viewer)const
+bool Scene_surface_mesh_item::testDisplayId(double x, double y, double z, CGAL::Three::Viewer_interface* viewer, const QVector3D& scaler)const
 {
   const CGAL::qglviewer::Vec offset = static_cast<CGAL::Three::Viewer_interface*>(CGAL::QGLViewer::QGLViewerPool().first())->offset();
   EPICK::Point_3 src(x - offset.x,
@@ -2138,13 +2138,14 @@ bool Scene_surface_mesh_item::testDisplayId(double x, double y, double z, CGAL::
                       z - offset.z);
 
   CGAL::qglviewer::Camera* cam = viewer->camera();
-  EPICK::Point_3 dest( cam->position().x - offset.x,
-                       cam->position().y - offset.y,
-                       cam->position().z - offset.z);
+  EPICK::Point_3 dest( cam->position().x/scaler.x() - offset.x,
+                       cam->position().y/scaler.y() - offset.y,
+                       cam->position().z/scaler.z() - offset.z);
   EPICK::Vector_3 v(src,dest);
   EPICK::Vector_3 dir(cam->viewDirection().x,
                       cam->viewDirection().y,
                       cam->viewDirection().z);
+
   if(-CGAL::scalar_product(v, dir) < cam->zNear()) //if src is behind the near plane, don't display.
     return false;
   v = 0.01*v;
diff --git a/Polyhedron/demo/Polyhedron/Scene_surface_mesh_item.h b/Polyhedron/demo/Polyhedron/Scene_surface_mesh_item.h
index d04f771899b..fba5cb89635 100644
--- a/Polyhedron/demo/Polyhedron/Scene_surface_mesh_item.h
+++ b/Polyhedron/demo/Polyhedron/Scene_surface_mesh_item.h
@@ -149,7 +149,7 @@ public:
   bool printFaceIds()const Q_DECL_OVERRIDE;
   void printAllIds() Q_DECL_OVERRIDE;
   bool shouldDisplayIds(CGAL::Three::Scene_item *current_item) const Q_DECL_OVERRIDE;
-  bool testDisplayId(double x, double y, double z, CGAL::Three::Viewer_interface*)const Q_DECL_OVERRIDE;
+  bool testDisplayId(double x, double y, double z, CGAL::Three::Viewer_interface*, const QVector3D &scaler)const Q_DECL_OVERRIDE;
   float alpha() const Q_DECL_OVERRIDE;
   void setAlpha(int alpha) Q_DECL_OVERRIDE;
   QSlider* alphaSlider();
diff --git a/Polyhedron/demo/Polyhedron/TextRenderer.cpp b/Polyhedron/demo/Polyhedron/TextRenderer.cpp
index 2e9ce45fefe..9a18b8d19ab 100644
--- a/Polyhedron/demo/Polyhedron/TextRenderer.cpp
+++ b/Polyhedron/demo/Polyhedron/TextRenderer.cpp
@@ -2,7 +2,7 @@
 #include <CGAL/Three/Scene_item.h>
 #include <CGAL/Three/Scene_print_item_interface.h>
 #include "Scene_polyhedron_selection_item.h"
-void TextRenderer::draw(CGAL::Three::Viewer_interface *viewer)
+void TextRenderer::draw(CGAL::Three::Viewer_interface *viewer, const QVector3D& scaler)
 {
     QPainter *painter = viewer->getPainter();
     if (!painter->isActive())
@@ -23,10 +23,15 @@ void TextRenderer::draw(CGAL::Three::Viewer_interface *viewer)
           if(viewer->testDisplayId(src.x, src.y, src.z))
           {
             if(item->is_3D())
-              rect = QRect(int(camera->projectedCoordinatesOf(src).x-item->width()/2),
-                           int(camera->projectedCoordinatesOf(src).y-item->height()/2),
+            {
+              src.x *= scaler.x();
+              src.y *= scaler.y();
+              src.z *= scaler.z();
+              rect = QRect(int(camera->projectedCoordinatesOf(src).x -item->width()/2),
+                           int(camera->projectedCoordinatesOf(src).y -item->height()/2),
                            int(item->width()),
                            int(item->height()));
+            }
             else
               rect = QRect(int(src.x-item->width()/2),
                            int(src.y-item->height()/2),
diff --git a/Polyhedron/demo/Polyhedron/Viewer.cpp b/Polyhedron/demo/Polyhedron/Viewer.cpp
index 95ede4b08db..b215784e429 100644
--- a/Polyhedron/demo/Polyhedron/Viewer.cpp
+++ b/Polyhedron/demo/Polyhedron/Viewer.cpp
@@ -17,6 +17,7 @@
 #include <QOpenGLDebugLogger>
 #include <QStyleFactory>
 #include <QAction>
+#include <QMultipleInputDialog.h>
 #include <QRegularExpressionMatch>
 #ifdef CGAL_USE_WEBSOCKETS
 #include <QtWebSockets/QWebSocket>
@@ -25,6 +26,7 @@
 #include <CGAL/Three/Three.h>
 
 #include "ui_LightingDialog.h"
+#include "CGAL_double_edit.h"
 
 #if defined(_WIN32)
 #include <QMimeData>
@@ -46,8 +48,10 @@ public:
   bool clipping;
   bool projection_is_ortho;
   bool cam_sharing;
+  bool scene_scaling;
   GLfloat gl_point_size;
   QVector4D clipbox[6];
+  QVector3D scaler;
   QPainter *painter;
 
   // L i g h t i n g
@@ -117,6 +121,7 @@ public:
   {
     return shader_programs;
   }
+
 #ifdef CGAL_USE_WEBSOCKETS
   QWebSocket m_webSocket;
 #endif
@@ -292,6 +297,8 @@ void Viewer::doBindings()
   d->textRenderer = new TextRenderer();
   d->is_2d_selection_mode = false;
   d->is_connected = false;
+  d->scene_scaling = false;
+  d->scaler = QVector3D(1,1,1);
 
   connect( d->textRenderer, SIGNAL(sendMessage(QString,int)),
            this, SLOT(printMessage(QString,int)) );
@@ -407,7 +414,7 @@ Viewer::~Viewer()
                              .arg(d->back_color.redF())
                              .arg(d->back_color.greenF())
                              .arg(d->back_color.blueF()));
-
+    makeCurrent();
     d->vao.destroy();
     if(d->_recentFunctions)
       delete d->_recentFunctions;
@@ -831,9 +838,23 @@ void Viewer::postSelection(const QPoint& pixel)
     point = camera()->pointUnderPixel(pixel, found) - offset();
   }
   if(found) {
-    Q_EMIT selectedPoint(point.x,
-                         point.y,
-                         point.z);
+    QVector3D transformed_point(point.x,
+                                point.y,
+                                point.z);
+    if(d->scene_scaling)
+    {
+      transformed_point = QVector3D(
+            point.x+offset().x,
+            point.y+offset().y,
+            point.z+offset().z);
+      transformed_point = transformed_point/d->scaler;
+      transformed_point[0] -=offset().x ;
+      transformed_point[1] -=offset().y ;
+      transformed_point[2] -=offset().z ;
+    }
+    Q_EMIT selectedPoint(transformed_point.x(),
+                         transformed_point.y(),
+                         transformed_point.z());
     CGAL::qglviewer::Vec dir;
     CGAL::qglviewer::Vec orig;
     if(d->projection_is_ortho)
@@ -931,6 +952,10 @@ void Viewer::attribBuffers(int program_name) const {
     this->camera()->getModelViewProjectionMatrix(d_mat);
     for (int i=0; i<16; ++i)
         mvp_mat.data()[i] = GLfloat(d_mat[i]);
+    if(d->scene_scaling){
+      mvp_mat.scale(d->scaler);
+      mv_mat.scale(d->scaler);
+    }
 
     QOpenGLShaderProgram* program = getShaderProgram(program_name);
     program->bind();
@@ -1130,7 +1155,7 @@ void Viewer::drawVisualHints()
     {
       d->textRenderer->addText(message_text);
     }
-    d->textRenderer->draw(this);
+    d->textRenderer->draw(this, d->scaler);
 
     if (d->_displayMessage)
       d->textRenderer->removeText(message_text);
@@ -1458,7 +1483,7 @@ void Viewer::wheelEvent(QWheelEvent* e)
 
 bool Viewer::testDisplayId(double x, double y, double z)
 {
-    return d->scene->testDisplayId(x,y,z,this);
+    return d->scene->testDisplayId(x,y,z,this, d->scaler);
 }
 
 QPainter* Viewer::getPainter(){return d->painter;}
@@ -1552,26 +1577,26 @@ void Viewer_impl::showDistance(QPoint pixel)
         rendering_program_dist.setAttributeBuffer("vertex",GL_FLOAT,0,3);
         buffer.release();
         vao.release();
-
         distance_is_displayed = true;
-        double dist = std::sqrt((BPoint.x-APoint.x)*(BPoint.x-APoint.x) + (BPoint.y-APoint.y)*(BPoint.y-APoint.y) + (BPoint.z-APoint.z)*(BPoint.z-APoint.z));
+        double dist = std::sqrt((BPoint.x-APoint.x)/scaler.x()*(BPoint.x-APoint.x)/scaler.x() + (BPoint.y-APoint.y)/scaler.y()*(BPoint.y-APoint.y)/scaler.y() + (BPoint.z-APoint.z)/scaler.z()*(BPoint.z-APoint.z)/scaler.z());
         QFont font;
         font.setBold(true);
         TextItem *ACoord = new TextItem(float(APoint.x),
                                         float(APoint.y),
                                         float(APoint.z),
                                         QString("A(%1,%2,%3)")
-                                        .arg(APoint.x-viewer->offset().x, 0, 'g', 10)
-                                        .arg(APoint.y-viewer->offset().y, 0, 'g', 10)
-                                        .arg(APoint.z-viewer->offset().z, 0, 'g', 10), true, font, Qt::red, true);
+                                        .arg(APoint.x/scaler.x()-viewer->offset().x, 0, 'g', 10)
+                                        .arg(APoint.y/scaler.y()-viewer->offset().y, 0, 'g', 10)
+                                        .arg(APoint.z/scaler.z()-viewer->offset().z, 0, 'g', 10), true, font, Qt::red, true);
         distance_text.append(ACoord);
         TextItem *BCoord = new TextItem(float(BPoint.x),
                                         float(BPoint.y),
                                         float(BPoint.z),
                                         QString("B(%1,%2,%3)")
-                                        .arg(BPoint.x-viewer->offset().x, 0, 'g', 10)
-                                        .arg(BPoint.y-viewer->offset().y, 0, 'g', 10)
-                                        .arg(BPoint.z-viewer->offset().z, 0, 'g', 10), true, font, Qt::red, true);
+                                        .arg(BPoint.x/scaler.x()-viewer->offset().x, 0, 'g', 10)
+                                        .arg(BPoint.y/scaler.y()-viewer->offset().y, 0, 'g', 10)
+                                        .arg(BPoint.z/scaler.z()-viewer->offset().z, 0, 'g', 10), true, font, Qt::red, true);
+
         distance_text.append(BCoord);
         CGAL::qglviewer::Vec centerPoint = 0.5*(BPoint+APoint);
         TextItem *centerCoord = new TextItem(float(centerPoint.x),
@@ -1583,12 +1608,12 @@ void Viewer_impl::showDistance(QPoint pixel)
         Q_FOREACH(TextItem* ti, distance_text)
           textRenderer->addText(ti);
         Q_EMIT(viewer->sendMessage(QString("First point : A(%1,%2,%3), second point : B(%4,%5,%6), distance between them : %7")
-                  .arg(APoint.x-viewer->offset().x)
-                  .arg(APoint.y-viewer->offset().y)
-                  .arg(APoint.z-viewer->offset().z)
-                  .arg(BPoint.x-viewer->offset().x)
-                  .arg(BPoint.y-viewer->offset().y)
-                  .arg(BPoint.z-viewer->offset().z)
+                  .arg(APoint.x/scaler.x()-viewer->offset().x)
+                  .arg(APoint.y/scaler.y()-viewer->offset().y)
+                  .arg(APoint.z/scaler.z()-viewer->offset().z)
+                  .arg(BPoint.x/scaler.x()-viewer->offset().x)
+                  .arg(BPoint.y/scaler.y()-viewer->offset().y)
+                  .arg(BPoint.z/scaler.z()-viewer->offset().z)
                   .arg(dist, 0, 'g', 10)));
     }
 
@@ -1958,6 +1983,56 @@ bool Viewer::isClipping() const
 {
   return d->clipping;
 }
+
+void Viewer::scaleScene()
+{
+  CGAL::Bbox_3 bbox = CGAL::Three::Three::scene()->bbox();
+  if(!d->scene_scaling)
+  {
+    QMultipleInputDialog dialog ("Scale Scene", CGAL::Three::Three::mainWindow());
+    DoubleEdit* x_val = dialog.add<DoubleEdit> ("Scale along X");
+    DoubleEdit* y_val = dialog.add<DoubleEdit> ("Scale along Y");
+    DoubleEdit* z_val = dialog.add<DoubleEdit> ("Scale along Z");
+    x_val->setMinimum(0);
+    y_val->setMinimum(0);
+    z_val->setMinimum(0);
+    if(bbox != CGAL::Bbox_3(0,0,0,0,0,0))
+    {
+      QPushButton* norm_button = dialog.add<QPushButton> ("");
+      norm_button->setText("Normalize");
+      norm_button->setToolTip("Automatically fill values to display the scene in a unit cube.");
+
+      connect(norm_button, &QPushButton::clicked, this,
+              [x_val, y_val, z_val, &bbox](){
+        x_val->setValue(1.0/(bbox.xmax()-bbox.xmin()));
+        y_val->setValue(1.0/(bbox.ymax()-bbox.ymin()));
+        z_val->setValue(1.0/(bbox.zmax()-bbox.zmin()));
+      });
+    }
+    if (dialog.exec() != QDialog::Accepted)
+    {
+      parent()->findChild<QAction*>("actionScaleScene")->setChecked(false);
+      return;
+    }
+    d->scaler.setX(x_val->text()==""?1.0:x_val->value());
+    d->scaler.setY(y_val->text()==""?1.0:y_val->value());
+    d->scaler.setZ(z_val->text()==""?1.0:z_val->value());
+
+    if(d->scaler.x() == 0.0 || d->scaler.y() == 0.0 || d->scaler.z()== 0.0)
+    {
+      parent()->findChild<QAction*>("actionScaleScene")->setChecked(false);
+      return;
+    }
+  }
+  else
+    d->scaler = QVector3D(1,1,1);
+
+  CGAL::qglviewer::Vec vmin(((float)bbox.xmin()+offset().x)*d->scaler.x(), ((float)bbox.ymin()+offset().y)*d->scaler.y(), ((float)bbox.zmin()+offset().z)*d->scaler.z()),
+      vmax(((float)bbox.xmax()+offset().x)*d->scaler.x(), ((float)bbox.ymax()+offset().y)*d->scaler.y(), ((float)bbox.zmax()+offset().z)*d->scaler.z());
+  camera()->setPivotPoint((vmin+vmax)*0.5);
+  camera()->fitBoundingBox(vmin, vmax);
+  d->scene_scaling = !d->scene_scaling;
+}
 #ifdef CGAL_USE_WEBSOCKETS
 void Viewer::setShareCam(bool b, QString session)
 {
diff --git a/Polyhedron/demo/Polyhedron/Viewer.h b/Polyhedron/demo/Polyhedron/Viewer.h
index 0d5bd3541df..7fceedbb0e7 100644
--- a/Polyhedron/demo/Polyhedron/Viewer.h
+++ b/Polyhedron/demo/Polyhedron/Viewer.h
@@ -137,7 +137,7 @@ public Q_SLOTS:
   void onSocketConnected();
   void onTextMessageSocketReceived(QString message);
 #endif
-
+  void scaleScene();
 protected:
   void paintEvent(QPaintEvent *)Q_DECL_OVERRIDE;
   void paintGL()Q_DECL_OVERRIDE;
diff --git a/Three/include/CGAL/Three/Scene_draw_interface.h b/Three/include/CGAL/Three/Scene_draw_interface.h
index 4ceaa728a23..d3ef745763f 100644
--- a/Three/include/CGAL/Three/Scene_draw_interface.h
+++ b/Three/include/CGAL/Three/Scene_draw_interface.h
@@ -61,7 +61,7 @@ public:
    * \param z the Z coordinate of theTextItem's position.
    * \param viewer the viewer used to display the Scene.
    * \return true if the TextItem is visible. */
-  virtual bool  testDisplayId(double x, double y, double z, CGAL::Three::Viewer_interface* viewer) = 0;
+  virtual bool  testDisplayId(double x, double y, double z, CGAL::Three::Viewer_interface* viewer, const QVector3D& scaler) = 0;
 
   ///\brief displays all the vertices ids if there are less than max_textItems.
   virtual void printVertexIds() = 0;
diff --git a/Three/include/CGAL/Three/Scene_print_item_interface.h b/Three/include/CGAL/Three/Scene_print_item_interface.h
index 3ad79996463..f6ff32c2374 100644
--- a/Three/include/CGAL/Three/Scene_print_item_interface.h
+++ b/Three/include/CGAL/Three/Scene_print_item_interface.h
@@ -48,7 +48,7 @@ public:
   //!
   //! \returns true if the Id should be displayed
   //! \returns false if the Id should not be displayed (if it is hidden for example)
-  virtual bool testDisplayId(double, double, double, CGAL::Three::Viewer_interface*)const = 0;
+  virtual bool testDisplayId(double, double, double, CGAL::Three::Viewer_interface*, const QVector3D& scaler)const = 0;
 
   //! \brief Tests if this item should display its ids.
   //!
diff --git a/Three/include/CGAL/Three/TextRenderer.h b/Three/include/CGAL/Three/TextRenderer.h
index 678a3cfc0b9..2d2f8e3a4c0 100644
--- a/Three/include/CGAL/Three/TextRenderer.h
+++ b/Three/include/CGAL/Three/TextRenderer.h
@@ -139,7 +139,7 @@ public:
     {
     }
     //!Draws all the `TextItem`s
-    void draw(CGAL::Three::Viewer_interface* viewer);
+    void draw(CGAL::Three::Viewer_interface* viewer, const QVector3D& scaler);
     //!\brief Adds a single TextItem to TextRenderer::local_textItems
     //!
     //! @see addText(float p_x, float p_y, float p_z, QString p_text, bool p_3D = true,  QFont font = QFont(), QColor p_color = Qt::black)