code: def signedDistance(actor, maxradius=0.5, bounds=(0, 1, 0, 1, 0, 1), dims=(10, 10, 10)):
      
      dist = vtk.vtkSignedDistance()
      dist.SetInputData(actor.polydata(True))
      dist.SetRadius(maxradius)
      dist.SetBounds(bounds)
      dist.SetDimensions(dims)
      dist.Update()
      return Volume(dist.GetOutput())
docs: ``vtkSignedDistance`` filter.
      :param float maxradius: how far out to propagate distance calculation
      :param list bounds: volume bounds.