diff --git a/apps/sample/trimesh_attribute/trimesh_attribute.cpp b/apps/sample/trimesh_attribute/trimesh_attribute.cpp
index b83426b2..a7d0fed3 100644
--- a/apps/sample/trimesh_attribute/trimesh_attribute.cpp
+++ b/apps/sample/trimesh_attribute/trimesh_attribute.cpp
@@ -66,10 +66,10 @@ int main()
    named_hv[i]   = 1.0f;  //                or an integer index
   }
 
-  // you can query if an attribute is present or not
+  // query if an attribute is present or not
   bool hasRadiosity = tri::HasPerVertexAttribute(m,"Radiosity");
 
-  // Once created with AddPerVertexAttribute, an handle to the attribute can be obtained as follows 
+  // obtain another handle of a previously attribute
   MyMesh::PerVertexAttributeHandle<float> ret_hv = tri::Allocator<MyMesh>::GetPerVertexAttribute<float>(m,"Radiosity");
 
   // you can also have PerMesh attributes
@@ -78,10 +78,10 @@ int main()
   // PerMesh attributes are accessed directly using the handle itself
   hm() = 10;
 
-  // you can delete an attribute by name
+  // delete an attribute by name
   tri::Allocator<MyMesh>::DeletePerVertexAttribute(m,"Radiosity");
 
-  // you can delete an attribute by handle
+  // delete an attribute by handle
   tri::Allocator<MyMesh>::DeletePerVertexAttribute(m,anon_hv);
 
   bool res;
diff --git a/apps/sample/trimesh_ball_pivoting/trimesh_ball_pivoting.cpp b/apps/sample/trimesh_ball_pivoting/trimesh_ball_pivoting.cpp
index 6a9560bf..4cc9d4e6 100644
--- a/apps/sample/trimesh_ball_pivoting/trimesh_ball_pivoting.cpp
+++ b/apps/sample/trimesh_ball_pivoting/trimesh_ball_pivoting.cpp
@@ -93,7 +93,7 @@ int  main(int argc, char **argv)
 		}
   vcg::tri::UpdateBounding<MyMesh>::Box(m);
   vcg::tri::UpdateNormal<MyMesh>::PerFace(m);
-  printf("Input mesh  vn:%i fn:%i\n",m.vn,m.fn);
+  printf("Input mesh  vn:%i fn:%i\n",m.VN(),m.FN());
 
   int t0=clock();
   // Initialization
@@ -106,7 +106,7 @@ int  main(int argc, char **argv)
 
   int t2=clock();
 
-  printf("Output mesh vn:%i fn:%i\n",m.vn,m.fn);
+  printf("Output mesh vn:%i fn:%i\n",m.VN(),m.FN());
   printf("Created in :%i msec (%i+%i)\n",t2-t0,t1-t0,t2-t1);
 	
   vcg::tri::io::PlyInfo pi;
diff --git a/apps/sample/trimesh_closest/trimesh_closest.cpp b/apps/sample/trimesh_closest/trimesh_closest.cpp
index 44707281..95245bc7 100644
--- a/apps/sample/trimesh_closest/trimesh_closest.cpp
+++ b/apps/sample/trimesh_closest/trimesh_closest.cpp
@@ -120,7 +120,7 @@ bool UnitTest_Closest(const char *filename1, int sampleNum, float dispPerc, std:
   TriMeshGrid TRGrid;
   if(useFaceNumForGrid)
   {
-    TRGrid.Set(mr.face.begin(),mr.face.end(),mr.fn*2);
+    TRGrid.Set(mr.face.begin(),mr.face.end(),mr.FN()*2);
   }
   else
   {
diff --git a/apps/sample/trimesh_clustering/trimesh_clustering.cpp b/apps/sample/trimesh_clustering/trimesh_clustering.cpp
index ebff7ca4..7c86f2f9 100644
--- a/apps/sample/trimesh_clustering/trimesh_clustering.cpp
+++ b/apps/sample/trimesh_clustering/trimesh_clustering.cpp
@@ -90,7 +90,7 @@ int  main(int argc, char **argv)
 		}
   vcg::tri::UpdateBounding<MyMesh>::Box(m);
   vcg::tri::UpdateNormal<MyMesh>::PerFace(m);
-  printf("Input mesh  vn:%i fn:%i\n",m.vn,m.fn);
+  printf("Input mesh  vn:%i fn:%i\n",m.VN(),m.FN());
   vcg::tri::Clustering<MyMesh, vcg::tri::AverageColorCell<MyMesh> > Grid;
   Grid.DuplicateFaceParam=DupFace;
   Grid.Init(m.bbox,CellNum,CellSize);
@@ -104,7 +104,7 @@ int  main(int argc, char **argv)
   int t1=clock();
   Grid.ExtractMesh(m);
   int t2=clock();
-  printf("Output mesh vn:%i fn:%i\n",m.vn,m.fn);
+  printf("Output mesh vn:%i fn:%i\n",m.VN(),m.FN());
   printf("Simplified in :%i msec (%i+%i)\n",t2-t0,t1-t0,t2-t1);
 	
   vcg::tri::io::PlyInfo pi;
diff --git a/apps/sample/trimesh_copy/trimeshcopy.cpp b/apps/sample/trimesh_copy/trimeshcopy.cpp
index b6dc8ff8..f8b30e1d 100644
--- a/apps/sample/trimesh_copy/trimeshcopy.cpp
+++ b/apps/sample/trimesh_copy/trimeshcopy.cpp
@@ -101,16 +101,16 @@ bool UnitTest_Append(const char *filename1, const char *filename2)
       exit(-1);
   }
   int endOpen = clock();
-  std::cout << "mesh loaded in " << float(endOpen-startOpen)/CLOCKS_PER_SEC << " msecs. Verts: " << mr.vn << " Faces: " << mr.fn << "\n";
+  std::cout << "mesh loaded in " << float(endOpen-startOpen)/CLOCKS_PER_SEC << " msecs. Verts: " << mr.VN() << " Faces: " << mr.FN() << "\n";
 
   int startCopy = clock();
   vcg::tri::Append<MeshType,MeshType>::Mesh(ml,mr,false,true);
   int endCopy = clock();
   std::cout << "mesh copied in " << float(endCopy-startCopy)/CLOCKS_PER_SEC << " msecs." << std::endl;
 
-  assert(ml.vn==mr.vn);
+  assert(ml.VN()==mr.VN());
   assert(ml.en==mr.en);
-  assert(ml.fn==mr.fn);
+  assert(ml.FN()==mr.FN());
 
   int startSave = clock();
   vcg::tri::io::ExporterPLY<MeshType>::Save(ml,filename2);
diff --git a/apps/sample/trimesh_curvature/trimesh_curvature.cpp b/apps/sample/trimesh_curvature/trimesh_curvature.cpp
index 15b1cb73..5fc897ce 100644
--- a/apps/sample/trimesh_curvature/trimesh_curvature.cpp
+++ b/apps/sample/trimesh_curvature/trimesh_curvature.cpp
@@ -22,7 +22,8 @@
 ****************************************************************************/
 #include<vcg/complex/complex.h>
 
-#include<wrap/io_trimesh/import_off.h>
+#include<wrap/io_trimesh/export_off.h>
+#include <vcg/complex/algorithms/create/platonic.h>
 
 #include<vcg/complex/algorithms/update/curvature.h>
 #include<vcg/complex/algorithms/update/normal.h>
@@ -44,26 +45,16 @@ class MyMesh    : public tri::TriMesh< vector<MyVertex>, vector<MyFace> , vector
 
 int main( int argc, char **argv )
 {
-  if(argc<2)
-  {
-    printf("Usage trimesh_base <meshfilename.obj>\n");
-    return -1;
-  }
-
   MyMesh m;
-
-  if(tri::io::ImporterOFF<MyMesh>::Open(m,argv[1])!=0)
-  {
-    printf("Error reading file  %s\n",argv[1]);
-    exit(0);
-  }
+  tri::Torus(m,30,10);
+  tri::io::ExporterOFF<MyMesh>::Save(m,"torus.off");
 
   tri::UpdateTopology<MyMesh>::FaceFace(m);
   tri::UpdateCurvature<MyMesh>::PerVertex(m);
-  tri::UpdateCurvature<MyMesh>::MeanAndGaussian(m);
-  tri::UpdateCurvature<MyMesh>::PrincipalDirections(m);
+//  tri::UpdateCurvature<MyMesh>::MeanAndGaussian(m);
+//  tri::UpdateCurvature<MyMesh>::PrincipalDirections(m);
   tri::UpdateCurvature<MyMesh>::PrincipalDirectionsNormalCycle(m);
-  tri::UpdateCurvature<MyMesh>::PrincipalDirectionsPCA(m,m.bbox.Diag()/100);
+//  tri::UpdateCurvature<MyMesh>::PrincipalDirectionsPCA(m,m.bbox.Diag()/100);
 
   tri::UpdateNormal<MyMesh>::PerVertexNormalized(m);
   printf("Input mesh  vn:%i fn:%i\n",m.VN(),m.FN());
diff --git a/apps/sample/trimesh_diskparam/trimesh_diskparam.cpp b/apps/sample/trimesh_diskparam/trimesh_diskparam.cpp
index 7333bd42..c02b62c3 100644
--- a/apps/sample/trimesh_diskparam/trimesh_diskparam.cpp
+++ b/apps/sample/trimesh_diskparam/trimesh_diskparam.cpp
@@ -64,7 +64,7 @@ int main( int argc, char **argv )
     return -1;
   }
 
-  printf("Mesh has %i vn %i fn\n",m.vn,m.fn);
+  printf("Mesh has %i vn %i fn\n",m.VN(),m.FN());
   tri::PoissonSolver<MyMesh> PS(m);
 
   if(!PS.IsFeaseable())
diff --git a/apps/sample/trimesh_edge/trimesh_edge.cpp b/apps/sample/trimesh_edge/trimesh_edge.cpp
index b3dca32f..4755bec2 100644
--- a/apps/sample/trimesh_edge/trimesh_edge.cpp
+++ b/apps/sample/trimesh_edge/trimesh_edge.cpp
@@ -201,7 +201,7 @@ int main( int argc, char **argv )
     exit(0);
   }
   tri::UpdateBounding<MyMesh>::Box(m);
-  printf("Input mesh  vn:%i fn:%i\n",m.vn,m.fn);
+  printf("Input mesh  vn:%i fn:%i\n",m.VN(),m.FN());
   srand(time(0));
 
   Plane3f slicingPlane;
@@ -210,7 +210,7 @@ int main( int argc, char **argv )
   vcg::IntersectionPlaneMesh<MyMesh, MyMesh, float>(m, slicingPlane, em );
   tri::Clean<MyMesh>::RemoveDuplicateVertex(em);
   vcg::tri::CapEdgeMesh(em,slice);
-  printf("Slice  mesh has %i vert and %i faces\n", slice.vn, slice.fn );
+  printf("Slice  mesh has %i vert and %i faces\n", slice.VN(), slice.FN() );
 
   MyMesh A,B;
   SplitMesh(m,A,B,slicingPlane);
@@ -218,7 +218,7 @@ int main( int argc, char **argv )
   tri::UpdatePosition<MyMesh>::Translate(B,-slicingPlane.Direction()*m.bbox.Diag()/80.0);
   tri::Append<MyMesh,MyMesh>::Mesh(sliced,A);
   tri::Append<MyMesh,MyMesh>::Mesh(sliced,B);
-  printf("Sliced mesh has %i vert and %i faces\n", sliced.vn, sliced.fn );
+  printf("Sliced mesh has %i vert and %i faces\n", sliced.VN(), sliced.FN() );
 
   tri::io::ExporterPLY<MyMesh>::Save(slice,"slice.ply",false);
   tri::io::ExporterPLY<MyMesh>::Save(sliced,"sliced.ply",false);
diff --git a/apps/sample/trimesh_join/trimesh_join.cpp b/apps/sample/trimesh_join/trimesh_join.cpp
index 66f7acb5..8ebe3fbe 100644
--- a/apps/sample/trimesh_join/trimesh_join.cpp
+++ b/apps/sample/trimesh_join/trimesh_join.cpp
@@ -97,12 +97,12 @@ int main(int argc,char **argv )
         printf("Error reading file  %s\n",argv[1]);
 			  exit(0);
 		  }
-      printf("Input mesh %3i           vn:%9i fn:%9i\n",i, mr.vn, mr.fn);
+      printf("Input mesh %3i           vn:%9i fn:%9i\n",i, mr.VN(), mr.FN());
       if(ClipFlag) 
       { 
         tri::GenericVertexInterpolator<MyMesh> interp(mr);
         tri::TriMeshClipper<MyMesh>::Box(ClipBB,interp,mr);
-        printf("              clipped to vn:%9i fn:%9i\n", mr.vn, mr.fn);
+        printf("              clipped to vn:%9i fn:%9i\n", mr.VN(), mr.FN());
       }
       tri::UpdateBounding<MyMesh>::Box(mr);
       TotBB.Add(mr.bbox);
@@ -111,7 +111,7 @@ int main(int argc,char **argv )
   		++i;
 		}
   
-  printf("Output mesh vn:%i fn:%i\n",ml.vn,ml.fn);
+  printf("Output mesh vn:%i fn:%i\n",ml.VN(),ml.FN());
 	
   tri::io::ExporterPLY<MyMesh>::Save(ml,"joined.ply");
   int dv=tri::Clean<MyMesh>::RemoveDuplicateVertex(ml); 
diff --git a/apps/sample/trimesh_optional/trimesh_optional.cpp b/apps/sample/trimesh_optional/trimesh_optional.cpp
index e4d1d696..820991ff 100644
--- a/apps/sample/trimesh_optional/trimesh_optional.cpp
+++ b/apps/sample/trimesh_optional/trimesh_optional.cpp
@@ -20,10 +20,8 @@
 * for more details.                                                         *
 *                                                                           *
 ****************************************************************************/
-#include<vcg/complex/complex.h>
 
-#include<vcg/simplex/vertex/component_ocf.h>
-#include<vcg/simplex/face/component_ocf.h>
+#include<vcg/complex/complex.h>
 
 #include<vcg/complex/algorithms/create/platonic.h>
 #include<vcg/complex/algorithms/update/topology.h>
@@ -65,12 +63,11 @@ int main(int , char **)
   tri::Tetrahedron(cm);
   tri::Tetrahedron(cmof);
  
-  printf("Generated mesh has %i vertices and %i triangular faces\n",cm.vn,cm.fn);
+  printf("Generated mesh has %i vertices and %i triangular faces\n",cm.VN(),cm.FN());
   
-  /// Calculates both vertex and face normals.
-  /// The normal of a vertex v is the weigthed average of the normals of the faces incident on v.
-  /// normals are not normalized
+  assert(tri::HasFFAdjacency(cmof) == false);
   cmof.face.EnableFFAdjacency();
+  assert(tri::HasFFAdjacency(cmof) == true);
 
   tri::UpdateTopology<CMesh   >::FaceFace(cm);
   tri::UpdateTopology<CMeshOcf>::FaceFace(cmof);
@@ -78,19 +75,22 @@ int main(int , char **)
   tri::UpdateFlags<CMesh   >::FaceBorderFromFF(cm);
   tri::UpdateFlags<CMeshOcf>::FaceBorderFromFF(cmof);
 
-  tri::UpdateNormal<CMesh   >::PerVertexNormalized(cm);
-  tri::UpdateNormal<CMeshOcf>::PerVertexNormalized(cmof);
+  tri::UpdateNormal<CMesh   >::PerVertexPerFace(cm);
+  cmof.face.EnableNormal();  // if you remove this the next line will throw an exception for a missing 'normal' component
+  tri::UpdateNormal<CMeshOcf>::PerVertexPerFace(cmof);
 
   printf("Normal of face 0 is %f %f %f\n\n",cm.face[0].N()[0],cm.face[0].N()[1],cm.face[0].N()[2]);
-  int t0=0,t1=0;
-  while(t1-t0<200)
+  int t0=0,t1=0,t2=0;
+  while(float(t1-t0)/CLOCKS_PER_SEC < 0.5)
   {
     t0=clock();
     tri::Refine(cm,tri::MidPointButterfly<CMesh>(cm),0);
     t1=clock();
     tri::Refine(cmof,tri::MidPointButterfly<CMeshOcf>(cmof),0);
+    t2=clock();
   }
 
+  printf("Last Iteration: Refined a tetra up to a mesh of %i faces in %5.2f %5.2f sec\n",cm.FN(),float(t1-t0)/CLOCKS_PER_SEC,float(t2-t1)/CLOCKS_PER_SEC);
 	cmof.vert.EnableRadius();
 	cmof.vert.EnableQuality();
 
@@ -118,7 +118,6 @@ int main(int , char **)
         {
           float q =vi->Q();
           float r =vi->R();
-//          int ii = vcg::tri::Index(cmof, *vi);
           assert(q==r);
         }
       }
diff --git a/apps/sample/trimesh_ray/trimesh_ray.cpp b/apps/sample/trimesh_ray/trimesh_ray.cpp
index 2fa3cb12..f7e0e5c5 100644
--- a/apps/sample/trimesh_ray/trimesh_ray.cpp
+++ b/apps/sample/trimesh_ray/trimesh_ray.cpp
@@ -148,7 +148,7 @@ int main(int argc,char ** argv)
 
   printf("Initializated in %i msec\n",t1-t0);
   printf("Completed in %i msec\n",t2-t1);
-  printf("Shoot %i rays and found %i intersections\n",m.vn*samplePerVert,totRay);
+  printf("Shoot %i rays and found %i intersections\n",m.VN()*samplePerVert,totRay);
 
 return 0;
 }
diff --git a/apps/sample/trimesh_refine/trimesh_refine.cpp b/apps/sample/trimesh_refine/trimesh_refine.cpp
index 7a7df42f..e848222a 100644
--- a/apps/sample/trimesh_refine/trimesh_refine.cpp
+++ b/apps/sample/trimesh_refine/trimesh_refine.cpp
@@ -96,7 +96,7 @@ int  main(int argc, char **argv)
   tri::UpdateTopology<MyMesh>::FaceFace(m);
   tri::UpdateFlags<MyMesh>::FaceBorderFromFF(m);
   tri::UpdateNormal<MyMesh>::PerVertexNormalized(m);
-  printf("Input mesh  vn:%i fn:%i\n",m.vn,m.fn);
+  printf("Input mesh  vn:%i fn:%i\n",m.VN(),m.FN());
 	
   n_steps=atoi(argv[3]);
 	
@@ -124,7 +124,7 @@ int  main(int argc, char **argv)
     }					
   }
   
-  printf("Output mesh vn:%i fn:%i\n",m.vn,m.fn);
+  printf("Output mesh vn:%i fn:%i\n",m.VN(),m.FN());
 
   vcg::tri::io::PlyInfo pi;
   pi.mask|=vcg::tri::io::Mask::IOM_BITPOLYGONAL;
diff --git a/apps/sample/trimesh_split_vertex/trimesh_split_vertex.cpp b/apps/sample/trimesh_split_vertex/trimesh_split_vertex.cpp
index 228e6863..d71bffc4 100644
--- a/apps/sample/trimesh_split_vertex/trimesh_split_vertex.cpp
+++ b/apps/sample/trimesh_split_vertex/trimesh_split_vertex.cpp
@@ -130,13 +130,13 @@ int main(int argc, char ** argv)
 	srcMesh.face.EnableWedgeTex();
 #endif
 	vcg::tri::io::ImporterPLY<SrcMesh>::Open(srcMesh, argv[1]);
-	if ((srcMesh.vn <= 0) || (srcMesh.fn <= 0))
+	if ((srcMesh.VN() <= 0) || (srcMesh.FN() <= 0))
 	{
 		printf("invalid source mesh file.\n");
 		return -1;
 	}
-	const int srcVN = srcMesh.vn;
-	const int srcFN = srcMesh.fn;
+	const int srcVN = srcMesh.VN();
+	const int srcFN = srcMesh.FN();
 	printf("source mesh succesfully loaded.\n");
 
 #ifdef TEST_IN_PLACE_SPLIT
@@ -154,8 +154,8 @@ int main(int argc, char ** argv)
 		return -1;
 	}
 	printf("destination mesh succesfully saved.\n");
-	const int dstVN = dstMesh.vn;
-	const int dstFN = dstMesh.fn;
+	const int dstVN = dstMesh.VN();
+	const int dstFN = dstMesh.FN();
 
 	printf("\n");
 	printf("statistics:\n");