    ug1 = vtkUniformGrid()
    # Geometry
    ug1.SetOrigin(origin)
    ug1.SetSpacing(spacing)
    ug1.SetDimensions(dims)

--
    ug2 = vtkUniformGrid()
    # Geometry
    ug2.SetOrigin(origin)
    ug2.SetSpacing(spacing2)
    ug2.SetDimensions(dims)

--
    ug3 = vtkUniformGrid()

    # Geometry
    ug3.SetOrigin(origin3)
    ug3.SetSpacing(spacing2)
    ug3.SetDimensions(dims)
