Transparent Torus renders in unwanted way

[paul-goblin]

Describe the bug

When I render a Torus or a similar shaped surface with opacity smaller than 1, it creates weird circular cross sections. There is one of these cross sections per resolution, ie. with resolution(20, 20) there are 19 cross sections rendered.

Code:

`class Test(ThreeDScene):

def construct(self):

    torus = Torus(resolution = (20, 20)).set_opacity(0.5)

    self.add(torus)`

Wrong display or Error traceback:

Additional context

This Problem is relevant in my case as I want to render loops on surfaces which should also be seen behind the torus (e.g. representing the generators of the fundamental group).