Hi Bill, thanks for your help, In your case, you did convert vtkImageData to vtkPolyData and use vtkWindowedSincPolyDataFilter to smooth vtkpolyData. If I don’t want to convert vtkImageData to vtkPolyData , can I obtain smooth result in 3D view using vtkImageData? -- Sent from: http://vtk.1045678.n5.nabble.com/VTK-Users-f1224199.html