    geometryFilter = vtkRectilinearGridGeometryFilter()
    geometryFilter.SetInputData(rgrid)
    geometryFilter.SetExtent(0, x + 1, 0, y + 1, (z + 1) // 2, (z + 1) // 2)
    geometryFilter.Update()

    rgridMapper = vtkPolyDataMapper()
--
    geometryFilter = vtkRectilinearGridGeometryFilter()
    geometryFilter.SetInputData(rgrid)
    geometryFilter.SetExtent(0, dimension, 0, dimension, int(dimension / 2), int(dimension / 2))
    geometryFilter.Update()

    rgridMapper = vtkPolyDataMapper()
--
    plane = vtkRectilinearGridGeometryFilter()
    plane.SetInputData(rgrid)
    plane.SetExtent(0, len(x) - 1, 16, 16, 0, len(z) - 1)

    rgridMapper = vtkPolyDataMapper()
    rgridMapper.SetInputConnection(plane.GetOutputPort())
