Hi all, How to get the normal of a particular point on a PolyData in vtk4.0, since vtkNormals is obsolete. in vtk3.2, we can use as below: PolyData.GetPointData().GetNormals().GetNormal(pointId) How about vtk4.0? Thanks, _________________________________________________________________ Chat with friends online, try MSN Messenger: http://messenger.msn.com