def orthogonal_proj(zfront, zback):
    a = (zfront + zback) / (zfront - zback)
b = -2 * (zfront * zback) / (zfront - zback)
return numpy.array([[1, 0, 0, 0], [0, 1, 0, 0], [0, 0, a, b], [0, 0, 0, zback]]
    )
proj3d.persp_transformation = orthogonal_proj
How to disable perspective in mplot3d?