diff --git a/Polyhedron/demo/Polyhedron/Scene_polylines_item.cpp b/Polyhedron/demo/Polyhedron/Scene_polylines_item.cpp
index 1c7309435d2..c7df02791ad 100644
--- a/Polyhedron/demo/Polyhedron/Scene_polylines_item.cpp
+++ b/Polyhedron/demo/Polyhedron/Scene_polylines_item.cpp
@@ -327,6 +327,11 @@ QMenu* Scene_polylines_item::contextMenu()
     QAction* action = menu->addAction(tr("Display corners with radius..."));
     connect(action, SIGNAL(triggered()),
             this, SLOT(change_corner_radii()));
+
+    QAction* actionSmoothPolylines = 
+      menu->addAction(tr("Smooth polylines"));
+    actionSmoothPolylines->setObjectName("actionSmoothPolylines");
+    connect(actionSmoothPolylines, SIGNAL(triggered()),this, SLOT(smooth()));
     menu->setProperty(prop_name, true);
   }
   return menu;
diff --git a/Polyhedron/demo/Polyhedron/Scene_polylines_item.h b/Polyhedron/demo/Polyhedron/Scene_polylines_item.h
index 7a612ca1d2e..a7ad624c002 100644
--- a/Polyhedron/demo/Polyhedron/Scene_polylines_item.h
+++ b/Polyhedron/demo/Polyhedron/Scene_polylines_item.h
@@ -7,6 +7,7 @@
 #include "Scene_item.h"
 
 #include <QString>
+#include <QMenu>
 
 #include <list>
 #include <vector>
@@ -47,7 +48,28 @@ public:
   void draw_edges() const;
 
   void draw_points() const;
-
+  
+  void smooth(std::vector<Point_3>& polyline){
+    bool is_closed = polyline.front()==polyline.back();
+    typedef K::Vector_3 Vector_3;
+    
+    std::size_t start = is_closed ? 0:1;
+    std::size_t end   = polyline.size()-1;
+    
+    Vector_3 prev = (is_closed ? polyline[end-1] : polyline[0]) - CGAL::ORIGIN;
+    
+    for (std::size_t i=start; i!=end; ++i)
+    {
+      Vector_3 curr = polyline[i] - CGAL::ORIGIN;
+      Vector_3 next = polyline[i+1] - CGAL::ORIGIN;
+      
+      polyline[i] = CGAL::ORIGIN+(prev+2*curr+next)/4;
+      prev=curr;
+    }
+    
+    if (is_closed) polyline[end]=polyline[0];
+  }
+  
 public slots:
   void change_corner_radii(double);
   void change_corner_radii();
@@ -55,6 +77,11 @@ public slots:
 
   void merge(Scene_polylines_item*);
 
+  void smooth(){
+    for (Polylines_container::iterator pit=polylines.begin(),pit_end=polylines.end();pit!=pit_end;++pit)
+      smooth(*pit);
+    emit itemChanged();
+  }
 public:
   Polylines_container polylines;