code: def surfaceIntersection(actor1, actor2, tol=1e-06, lw=3):
      
      bf = vtk.vtkIntersectionPolyDataFilter()
      poly1 = actor1.GetMapper().GetInput()
      poly2 = actor2.GetMapper().GetInput()
      bf.SetInputData(0, poly1)
      bf.SetInputData(1, poly2)
      bf.Update()
      actor = Actor(bf.GetOutput(), "k", 1)
      actor.GetProperty().SetLineWidth(lw)
      return actor
docs: Intersect 2 surfaces and return a line actor.
  
      .. hint:: |surfIntersect.py|_