Hi Will,
Thank you for your reply.
I used vtkWindowedSincPolyDataFilter and SetEdgeAngle. it was perfect. Thanks.
windowed = vtk.vtkWindowedSincPolyDataFilter()
windowed.SetInputData(part)
windowed.SetNumberOfIterations(20)
windowed.FeatureEdgeSmoothingOn()
windowed.SetFeatureAngle(180)
windowed.BoundarySmoothingOn()
windowed.SetEdgeAngle(180)
windowed.Update()