Dear Martin, Have you tried vtkSelectPolyData(to generate scalars)-->vtkClipPolyData(using input scalar data)? Good luck Regards, Yue -- View this message in context: http://vtk.1045678.n5.nabble.com/Cut-a-triangulated-surface-with-a-line-tp5722012p5724913.html Sent from the VTK - Users mailing list archive at Nabble.com.