code: def projectSphereFilter(actor):
      
      poly = actor.polydata()
      psf = vtk.vtkProjectSphereFilter()
      psf.SetInputData(poly)
      psf.Update()
      a = Actor(psf.GetOutput())
      return a
docs: Project a spherical-like object onto a plane.
  
      .. hint:: |projectsphere| |projectsphere.py|_