Hi guys. This is just to inform that I also found the same problem when unwanted cells are deleted. I will check Andy's solution now. -m -- View this message in context: http://vtk.1045678.n5.nabble.com/Fwd-Bug-in-vtkPolyData-tp5729465p5729553.html Sent from the VTK - Users mailing list archive at Nabble.com.