Yes you're right. So in fact, the best option for me would be to obtain the right image instead of the left image without compute the normals. But I don't know if it is possible. -- View this message in context: http://vtk.1045678.n5.nabble.com/vtkNormal-tp5450164p5453144.html Sent from the VTK - Users mailing list archive at Nabble.com.