    surface = vtkParametricKuen()
    source = vtkParametricFunctionSource()

    renderer = vtkRenderer()
    mapper = vtkPolyDataMapper()
    actor = vtkActor()
--
    pfn['Kuen'] = vtkParametricKuen()
    pfn['PluckerConoid'] = vtkParametricPluckerConoid()
    pfn['Pseudosphere'] = vtkParametricPseudosphere()
    # Now set some parameters.
    pfn["Ellipsoid"].SetXRadius(0.5)
    pfn["Ellipsoid"].SetYRadius(2.0)
