Hi vtkusers, i have generated the the mesh with vtkClipVolume. Could anyone tell me how to get the points and cells in the vtkUnstructuredGrid and revise them. I don't know the structure of the class very much, and how to use the function in the class. Should anyone give me a example!!!!!!!! Best regards! Longfei Cong lfcong at nlpr.ia.ac.cn 2004-03-12