diff --git a/source/blender/freestyle/intern/application/Controller.cpp b/source/blender/freestyle/intern/application/Controller.cpp
index eb27ab62340..d7f91d3d7c2 100755
--- a/source/blender/freestyle/intern/application/Controller.cpp
+++ b/source/blender/freestyle/intern/application/Controller.cpp
@@ -93,6 +93,7 @@ Controller::Controller()
   _winged_edge = NULL;
   
   _pView = NULL;
+  _pRenderMonitor = NULL;
 
   _edgeTesselationNature = (Nature::SILHOUETTE | Nature::BORDER | Nature::CREASE);
 
@@ -181,6 +182,11 @@ void Controller::setView(AppView *iView)
   _Canvas->setViewer(_pView);
 }
 
+void Controller::setRenderMonitor(RenderMonitor *iRenderMonitor)
+{
+  _pRenderMonitor = iRenderMonitor;
+}
+
 void Controller::setPassDiffuse(float *buf, int width, int height)
 {
   AppCanvas *app_canvas = dynamic_cast<AppCanvas *>(_Canvas);
@@ -206,6 +212,8 @@ int Controller::LoadMesh(Render *re, SceneRenderLayer* srl)
 {
   
   BlenderFileLoader loader(re, srl);
+
+  loader.setRenderMonitor(_pRenderMonitor);
   
   _Chrono.start();
   
@@ -242,11 +250,15 @@ int Controller::LoadMesh(Render *re, SceneRenderLayer* srl)
   _pView->setModel(_RootNode);
   //_pView->FitBBox();
 
+  if (_pRenderMonitor->testBreak())
+    return 0;
+
 
   _Chrono.start();
 
   
   WXEdgeBuilder wx_builder;
+  wx_builder.setRenderMonitor(_pRenderMonitor);
   blenderScene->accept(wx_builder);
   _winged_edge = wx_builder.getWingedEdge();
 
@@ -465,11 +477,15 @@ void Controller::ComputeViewMap()
   edgeDetector.setCreaseAngle(_creaseAngle);
   edgeDetector.setSphereRadius(_sphereRadius);
   edgeDetector.setSuggestiveContourKrDerivativeEpsilon(_suggestiveContourKrDerivativeEpsilon);
+  edgeDetector.setRenderMonitor(_pRenderMonitor);
   edgeDetector.processShapes(*_winged_edge);
 
   real duration = _Chrono.stop();
   printf("Feature lines    : %lf\n", duration);
 
+  if (_pRenderMonitor->testBreak())
+    return;
+
   // Builds the view map structure from the flagged WSEdge structure:
   //----------------------------------------------------------
   ViewMapBuilder vmBuilder;
@@ -478,6 +494,7 @@ void Controller::ComputeViewMap()
   vmBuilder.setTransform( mv, proj,viewport, _pView->GetFocalLength(), _pView->GetAspect(), _pView->GetFovyRadian());
   vmBuilder.setFrustum(_pView->znear(), _pView->zfar());  
   vmBuilder.setGrid(&_Grid);
+  vmBuilder.setRenderMonitor(_pRenderMonitor);
   
   // Builds a tesselated form of the silhouette for display purpose:
   //---------------------------------------------------------------
diff --git a/source/blender/freestyle/intern/application/Controller.h b/source/blender/freestyle/intern/application/Controller.h
index 4ee79405fa9..6119e14f7b7 100755
--- a/source/blender/freestyle/intern/application/Controller.h
+++ b/source/blender/freestyle/intern/application/Controller.h
@@ -38,6 +38,7 @@
 # include "../system/ProgressBar.h"
 # include "../system/Precision.h"
 # include "../system/Interpreter.h"
+# include "../system/RenderMonitor.h"
 # include "../view_map/FEdgeXDetector.h"
 
 class AppView;
@@ -69,6 +70,7 @@ public:
   ~Controller() ;
   
   void setView(AppView *iView);
+  void setRenderMonitor(RenderMonitor *iRenderMonitor);
   void setPassDiffuse(float *buf, int width, int height);
   void setPassZ(float *buf, int width, int height);
   void setContext(bContext *C);
@@ -177,6 +179,8 @@ private:
   //Viewer2DWindow *_pView2DWindow;
   //Viewer2D *_pView2D;
   
+  RenderMonitor *_pRenderMonitor;
+
   //Model
   // Drawing Structure
   NodeGroup *_RootNode;
diff --git a/source/blender/freestyle/intern/blender_interface/BlenderFileLoader.cpp b/source/blender/freestyle/intern/blender_interface/BlenderFileLoader.cpp
index 492fbf239ad..2b2e92f57dd 100644
--- a/source/blender/freestyle/intern/blender_interface/BlenderFileLoader.cpp
+++ b/source/blender/freestyle/intern/blender_interface/BlenderFileLoader.cpp
@@ -40,6 +40,8 @@ NodeGroup* BlenderFileLoader::Load()
 
 	int id = 0;
 	for(obi= (ObjectInstanceRen *) _re->instancetable.first; obi; obi=obi->next) {
+		if (_pRenderMonitor && _pRenderMonitor->testBreak())
+			break;
 		if (!(obi->lay & _srl->lay))
 			continue;
 		char *name = obi->ob->id.name;
diff --git a/source/blender/freestyle/intern/blender_interface/BlenderFileLoader.h b/source/blender/freestyle/intern/blender_interface/BlenderFileLoader.h
index 804b1eb635d..c5c06567c41 100644
--- a/source/blender/freestyle/intern/blender_interface/BlenderFileLoader.h
+++ b/source/blender/freestyle/intern/blender_interface/BlenderFileLoader.h
@@ -5,6 +5,7 @@
 # include <float.h>
 
 # include "../system/FreestyleConfig.h"
+# include "../system/RenderMonitor.h"
 # include "../scene_graph/NodeGroup.h"
 # include "../scene_graph/NodeTransform.h"
 # include "../scene_graph/NodeShape.h"
@@ -64,6 +65,9 @@ public:
   /*! Gets the smallest edge size read */
   inline real minEdgeSize() {return _minEdgeSize;}
 
+  /*! Modifiers */
+  inline void setRenderMonitor(RenderMonitor *iRenderMonitor) {_pRenderMonitor = iRenderMonitor;}
+
 protected:
 	void insertShapeNode(ObjectInstanceRen *obi, int id);
 	int testDegenerateTriangle(float v1[3], float v2[3], float v3[3]);
@@ -93,6 +97,8 @@ protected:
 	float _viewplane_bottom;
 	float _viewplane_top;
 	float _z_near, _z_far;
+
+	RenderMonitor *_pRenderMonitor;
 };
 
 #endif // BLENDER_FILE_LOADER_H
diff --git a/source/blender/freestyle/intern/blender_interface/FRS_freestyle.cpp b/source/blender/freestyle/intern/blender_interface/FRS_freestyle.cpp
index fe37b89999e..5dcda3bd69c 100644
--- a/source/blender/freestyle/intern/blender_interface/FRS_freestyle.cpp
+++ b/source/blender/freestyle/intern/blender_interface/FRS_freestyle.cpp
@@ -462,6 +462,9 @@ extern "C" {
 	Render* FRS_do_stroke_rendering(Render* re, SceneRenderLayer *srl) {
 		
 		Render* freestyle_render = NULL;
+
+		RenderMonitor monitor(re);
+		controller->setRenderMonitor(&monitor);
 		
 		cout << "\n----------------------------------------------------------" << endl;
 		cout << "|  " << (re->scene->id.name+2) << "|" << srl->name << endl;
@@ -476,6 +479,7 @@ extern "C" {
 
         if( re->test_break(re->tbh) ) {
 			controller->CloseFile();
+			cout << "Break" << endl;
             return NULL;
         }
 
diff --git a/source/blender/freestyle/intern/system/RenderMonitor.h b/source/blender/freestyle/intern/system/RenderMonitor.h
new file mode 100644
index 00000000000..7d148e65c90
--- /dev/null
+++ b/source/blender/freestyle/intern/system/RenderMonitor.h
@@ -0,0 +1,47 @@
+//
+//  Copyright (C) : Please refer to the COPYRIGHT file distributed 
+//   with this source distribution. 
+//
+//  This program is free software; you can redistribute it and/or
+//  modify it under the terms of the GNU General Public License
+//  as published by the Free Software Foundation; either version 2
+//  of the License, or (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU General Public License for more details.
+//
+//  You should have received a copy of the GNU General Public License
+//  along with this program; if not, write to the Free Software
+//  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#ifndef RENDERMONITOR_H
+#define RENDERMONITOR_H
+
+extern "C" {
+#include "render_types.h"
+}
+
+class RenderMonitor
+{
+public:
+
+  inline RenderMonitor(Render *re) {
+    _re = re;
+  }
+
+  virtual ~RenderMonitor() {}
+
+  inline bool testBreak() {
+    return _re && _re->test_break(_re->tbh);
+  }
+ 
+protected:
+
+  Render *_re;
+};
+
+#endif // RENDERMONITOR_H
diff --git a/source/blender/freestyle/intern/view_map/FEdgeXDetector.cpp b/source/blender/freestyle/intern/view_map/FEdgeXDetector.cpp
index 1cbed8a87c6..1d52f37236e 100755
--- a/source/blender/freestyle/intern/view_map/FEdgeXDetector.cpp
+++ b/source/blender/freestyle/intern/view_map/FEdgeXDetector.cpp
@@ -42,6 +42,8 @@ void FEdgeXDetector::processShapes(WingedEdge& we) {
   for(vector<WShape*>::const_iterator it = wshapes.begin();
   it != wshapes.end();
   it++){
+    if (_pRenderMonitor && _pRenderMonitor->testBreak())
+      break;
     wxs = dynamic_cast<WXShape*>(*it);
     wxs->bbox(Min, Max);
     _bbox_diagonal = (Max-Min).norm();
diff --git a/source/blender/freestyle/intern/view_map/FEdgeXDetector.h b/source/blender/freestyle/intern/view_map/FEdgeXDetector.h
index d73a086f81d..2fd6a4a1e8f 100755
--- a/source/blender/freestyle/intern/view_map/FEdgeXDetector.h
+++ b/source/blender/freestyle/intern/view_map/FEdgeXDetector.h
@@ -38,6 +38,7 @@
 # include "../winged_edge/WXEdge.h"
 # include "../winged_edge/Curvature.h"
 # include "../system/ProgressBar.h"
+# include "../system/RenderMonitor.h"
 
 using namespace Geometry;
 
@@ -50,6 +51,7 @@ public:
 
   FEdgeXDetector() {
     _pProgressBar = 0;
+    _pRenderMonitor = 0;
     _computeViewIndependant = true;
     _bbox_diagonal = 1.0;
     _meanEdgeSize = 0;
@@ -165,6 +167,8 @@ public:
 
   inline void setProgressBar(ProgressBar *iProgressBar) {_pProgressBar = iProgressBar;}
 
+  inline void setRenderMonitor(RenderMonitor *iRenderMonitor) {_pRenderMonitor = iRenderMonitor;}
+
 protected:
 
   Vec3r _Viewpoint;
@@ -193,6 +197,7 @@ protected:
   real _kr_derivative_epsilon;
 
   ProgressBar *_pProgressBar;
+  RenderMonitor *_pRenderMonitor;
 };
 
 #endif // FEDGEDXETECTOR_H
diff --git a/source/blender/freestyle/intern/view_map/ViewMapBuilder.cpp b/source/blender/freestyle/intern/view_map/ViewMapBuilder.cpp
index 242b769e8b5..d503daa3696 100755
--- a/source/blender/freestyle/intern/view_map/ViewMapBuilder.cpp
+++ b/source/blender/freestyle/intern/view_map/ViewMapBuilder.cpp
@@ -378,7 +378,7 @@ cout << "\t\tIs occluder" << endl;
 // a QI of 22 because 3 out of 6 occluders have QI <= 22.
 
 template <typename G, typename I>
-static void computeCumulativeVisibility(ViewMap *ioViewMap, G& grid, real epsilon)
+static void computeCumulativeVisibility(ViewMap *ioViewMap, G& grid, real epsilon, RenderMonitor *iRenderMonitor)
 {
   vector<ViewEdge*>& vedges = ioViewMap->ViewEdges();
 
@@ -391,6 +391,8 @@ static void computeCumulativeVisibility(ViewMap *ioViewMap, G& grid, real epsilo
   unsigned maxIndex, maxCard;
   unsigned qiMajority;
   for(vector<ViewEdge*>::iterator ve=vedges.begin(), veend=vedges.end(); ve!=veend; ve++) {
+    if (iRenderMonitor && iRenderMonitor->testBreak())
+      break;
 #if logging > 0
 cout << "Processing ViewEdge " << (*ve)->getId() << endl;
 #endif
@@ -538,7 +540,7 @@ cout << "\tConclusion: QI = " << maxIndex << ", " << (*ve)->occluders_size() <<
 }
 
 template <typename G, typename I>
-static void computeDetailedVisibility(ViewMap *ioViewMap, G& grid, real epsilon)
+static void computeDetailedVisibility(ViewMap *ioViewMap, G& grid, real epsilon, RenderMonitor *iRenderMonitor)
 {
   vector<ViewEdge*>& vedges = ioViewMap->ViewEdges();
 
@@ -551,6 +553,8 @@ static void computeDetailedVisibility(ViewMap *ioViewMap, G& grid, real epsilon)
   unsigned maxIndex, maxCard;
   unsigned qiMajority;
   for(vector<ViewEdge*>::iterator ve=vedges.begin(), veend=vedges.end(); ve!=veend; ve++) {
+    if (iRenderMonitor && iRenderMonitor->testBreak())
+      break;
 #if logging > 0
 cout << "Processing ViewEdge " << (*ve)->getId() << endl;
 #endif
@@ -1115,6 +1119,9 @@ void ViewMapBuilder::computeInitialViewEdges(WingedEdge& we)
   for (vector<WShape*>::const_iterator it = wshapes.begin();
        it != wshapes.end();
        it++) {
+    if (_pRenderMonitor && _pRenderMonitor->testBreak())
+      break;
+
     // create the embedding
     psShape = new SShape;
     psShape->setId((*it)->GetId());
@@ -1151,6 +1158,8 @@ void ViewMapBuilder::computeCusps(ViewMap *ioViewMap){
   for(;
   ve!=veend;
   ++ve){
+    if (_pRenderMonitor && _pRenderMonitor->testBreak())
+      break;
     if((!((*ve)->getNature() & Nature::SILHOUETTE)) || (!((*ve)->fedgeA()->isSmooth())))
       continue;
     FEdge *fe = (*ve)->fedgeA();
@@ -1236,10 +1245,10 @@ void ViewMapBuilder::ComputeCumulativeVisibility(ViewMap *ioViewMap,
 
 	if ( _orthographicProjection ) {
 		BoxGrid grid(*source, *density, ioViewMap, _viewpoint, _EnableQI);
-		computeCumulativeVisibility<BoxGrid, BoxGrid::Iterator>(ioViewMap, grid, epsilon);
+		computeCumulativeVisibility<BoxGrid, BoxGrid::Iterator>(ioViewMap, grid, epsilon, _pRenderMonitor);
 	} else {
 		SphericalGrid grid(*source, *density, ioViewMap, _viewpoint, _EnableQI);
-		computeCumulativeVisibility<SphericalGrid, SphericalGrid::Iterator>(ioViewMap, grid, epsilon);
+		computeCumulativeVisibility<SphericalGrid, SphericalGrid::Iterator>(ioViewMap, grid, epsilon, _pRenderMonitor);
 	}
 }
 
@@ -1265,10 +1274,10 @@ void ViewMapBuilder::ComputeDetailedVisibility(ViewMap *ioViewMap,
 
 	if ( _orthographicProjection ) {
 		BoxGrid grid(*source, *density, ioViewMap, _viewpoint, _EnableQI);
-		computeDetailedVisibility<BoxGrid, BoxGrid::Iterator>(ioViewMap, grid, epsilon);
+		computeDetailedVisibility<BoxGrid, BoxGrid::Iterator>(ioViewMap, grid, epsilon, _pRenderMonitor);
 	} else {
 		SphericalGrid grid(*source, *density, ioViewMap, _viewpoint, _EnableQI);
-		computeDetailedVisibility<SphericalGrid, SphericalGrid::Iterator>(ioViewMap, grid, epsilon);
+		computeDetailedVisibility<SphericalGrid, SphericalGrid::Iterator>(ioViewMap, grid, epsilon, _pRenderMonitor);
 	}
 }
 
@@ -1378,6 +1387,8 @@ void ViewMapBuilder::ComputeRayCastingVisibility(ViewMap *ioViewMap, real epsilo
   ve!=veend;
   ve++)
   {
+    if (_pRenderMonitor && _pRenderMonitor->testBreak())
+      break;
 #if logging > 0
 cout << "Processing ViewEdge " << (*ve)->getId() << endl;
 #endif
@@ -1525,6 +1536,9 @@ void ViewMapBuilder::ComputeFastRayCastingVisibility(ViewMap *ioViewMap, real ep
   ve!=veend;
   ve++)
   {
+    if (_pRenderMonitor && _pRenderMonitor->testBreak())
+      break;
+
     festart = (*ve)->fedgeA();
     fe = (*ve)->fedgeA();
     qiMajority = 1;
@@ -1653,6 +1667,9 @@ void ViewMapBuilder::ComputeVeryFastRayCastingVisibility(ViewMap *ioViewMap, rea
   ve!=veend;
   ve++)
   {
+    if (_pRenderMonitor && _pRenderMonitor->testBreak())
+      break;
+
     set<ViewShape*> occluders;
 
     fe = (*ve)->fedgeA();
@@ -2136,6 +2153,9 @@ void ViewMapBuilder::ComputeSweepLineIntersections(ViewMap *ioViewMap, real epsi
   sv!=svend;
   sv++)
   {
+    if (_pRenderMonitor && _pRenderMonitor->testBreak())
+      break;
+
     const vector<FEdge*>& vedges = (*sv)->fedges();
     
     for(vector<FEdge*>::const_iterator sve=vedges.begin(), sveend=vedges.end();
@@ -2159,6 +2179,19 @@ void ViewMapBuilder::ComputeSweepLineIntersections(ViewMap *ioViewMap, real epsi
     vsegments.clear();
   }
 
+  if (_pRenderMonitor && _pRenderMonitor->testBreak()) {
+    // delete segments
+    if(!segments.empty()){
+      vector<segment* >::iterator s, send;
+      for(s=segments.begin(),send=segments.end();
+      s!=send;
+      s++){
+        delete *s;
+      }
+    }
+    return;
+  }
+
   // reset userdata:
   for(fe=ioEdges.begin(), fend=ioEdges.end();
   fe!=fend;
diff --git a/source/blender/freestyle/intern/view_map/ViewMapBuilder.h b/source/blender/freestyle/intern/view_map/ViewMapBuilder.h
index 2e37a41df3c..a41df92062e 100755
--- a/source/blender/freestyle/intern/view_map/ViewMapBuilder.h
+++ b/source/blender/freestyle/intern/view_map/ViewMapBuilder.h
@@ -40,6 +40,7 @@
 # include "../geometry/GeomUtils.h"
 # include "../geometry/Grid.h"
 # include "../system/ProgressBar.h"
+# include "../system/RenderMonitor.h"
 # include "../geometry/SweepLine.h"
 # include "ViewMap.h"
 # include "SilhouetteGeomEngine.h"
@@ -58,6 +59,7 @@ private:
   ViewMap * _ViewMap; // result
   //SilhouetteGeomEngine _GeomEngine;
   ProgressBar *_pProgressBar;
+  RenderMonitor *_pRenderMonitor;
   Vec3r _viewpoint;
   bool _orthographicProjection;
   Grid* _Grid;
@@ -91,6 +93,7 @@ public:
   inline ViewMapBuilder()
   {
     _pProgressBar = 0;
+    _pRenderMonitor = 0;
     _Grid = 0;
     _currentId = 1;
     _currentFId = 0;
@@ -185,6 +188,7 @@ public:
  
   /*! Modifiers */
   inline void setProgressBar(ProgressBar *iProgressBar) {_pProgressBar = iProgressBar;}
+  inline void setRenderMonitor(RenderMonitor *iRenderMonitor) {_pRenderMonitor = iRenderMonitor;}
   inline void setEnableQI(bool iBool) {_EnableQI = iBool;}
 
 protected:
diff --git a/source/blender/freestyle/intern/winged_edge/WXEdgeBuilder.cpp b/source/blender/freestyle/intern/winged_edge/WXEdgeBuilder.cpp
index 80e06fc2b7b..b29f0c7e9ee 100755
--- a/source/blender/freestyle/intern/winged_edge/WXEdgeBuilder.cpp
+++ b/source/blender/freestyle/intern/winged_edge/WXEdgeBuilder.cpp
@@ -23,6 +23,8 @@
 
 void WXEdgeBuilder::visitIndexedFaceSet(IndexedFaceSet& ifs)
 {
+  if (_pRenderMonitor && _pRenderMonitor->testBreak())
+    return;
   WXShape *shape = new WXShape;
   buildWShape(*shape, ifs);
   shape->setId(ifs.getId().getFirst());
diff --git a/source/blender/freestyle/intern/winged_edge/WingedEdgeBuilder.cpp b/source/blender/freestyle/intern/winged_edge/WingedEdgeBuilder.cpp
index 40c14eafe72..e56ac0f9c42 100755
--- a/source/blender/freestyle/intern/winged_edge/WingedEdgeBuilder.cpp
+++ b/source/blender/freestyle/intern/winged_edge/WingedEdgeBuilder.cpp
@@ -26,6 +26,8 @@
 using namespace std;
 
 void WingedEdgeBuilder::visitIndexedFaceSet(IndexedFaceSet& ifs) {
+  if (_pRenderMonitor && _pRenderMonitor->testBreak())
+    return;
   WShape *shape = new WShape;
   buildWShape(*shape, ifs);
   shape->setId(ifs.getId().getFirst());
diff --git a/source/blender/freestyle/intern/winged_edge/WingedEdgeBuilder.h b/source/blender/freestyle/intern/winged_edge/WingedEdgeBuilder.h
index 8e9d0122e35..972d67355d2 100755
--- a/source/blender/freestyle/intern/winged_edge/WingedEdgeBuilder.h
+++ b/source/blender/freestyle/intern/winged_edge/WingedEdgeBuilder.h
@@ -33,6 +33,7 @@
 # define WINGED_EDGE_BUILDER_H
 
 # include "../system/FreestyleConfig.h"
+# include "../system/RenderMonitor.h"
 # include "../scene_graph/SceneVisitor.h"
 # include "WEdge.h"
 # include "../scene_graph/IndexedFaceSet.h"
@@ -47,6 +48,7 @@ class LIB_WINGED_EDGE_EXPORT WingedEdgeBuilder : public SceneVisitor
     _current_frs_material = NULL;
     _current_matrix = NULL;
     _winged_edge = new WingedEdge; // Not deleted by the destructor
+    _pRenderMonitor = NULL;
   }
 
   virtual ~WingedEdgeBuilder() {
@@ -101,6 +103,10 @@ class LIB_WINGED_EDGE_EXPORT WingedEdgeBuilder : public SceneVisitor
   //    _current_matrix = matrix;
   //  }
 
+  inline void setRenderMonitor(RenderMonitor *iRenderMonitor) {
+    _pRenderMonitor = iRenderMonitor;
+  }
+
  protected:
 
   virtual void buildWShape(WShape& shape, IndexedFaceSet& ifs);
@@ -108,6 +114,8 @@ class LIB_WINGED_EDGE_EXPORT WingedEdgeBuilder : public SceneVisitor
 			      const real *vertices,
 			      unsigned vsize);
 
+  RenderMonitor *_pRenderMonitor;
+
  private:
 
   void buildTriangleStrip(const real *vertices,