You are correct - I used rings instead of accretion disk because it allows a bit more visible detail in what particles go where. As far as I'm aware, because the particles are massless, the difference is purely visual. Real accretion disks would be blindingly bright anyway, far more than red hot, more like x-ray hot, especially in a violent situation like this.
It is 3D I assure you, it is just viewed perpendicular to the black holes orbit(s) for viewing clarity/simplicity. I could have put the camera at any angle but doing so would just make it less clear what's going on.
