ockham - neat idea you have there, Certainly interesting, as you and jonthecelt both observed, how the choice of rotation angle makes a difference. A while back made a similar thing, 3 rings of differing speeds (to create parallax scrolling), and in that, your idea and also this weekend freebie, theres one annoying constant. Unless you really zoom in on a tight area, the scene background is always obviously circular. Which means if we wanted to get an effect like the repeating backgrounds seen in Tom & Jerry or the Simpsons wouldn't work. For that I think whats needed is some form of "belt" made up from 4 (or better still more) "plates". Much like the roll of paper used by some animators which sat underneath the animation cel and was controlled by 2 handles. Sorry I forget what this is actually called. But the idea - as per picture - is basically the same. The plates are all identical and have no visible gap twxit them moves from right to left and rotate around 2 pivot points. Eventually the 1st image returns back to the front. I've used a cylindrical 'rotate back' here, but it doesn't have to be like that in actuality. Thats because the scene camera is kept carefully to one plate you wouldn't see how it rotated. But a cube doesn't work because you'd see the edges as it rotates. Hence my feeling on a plate and belt approach, like a caterpillar track. Which could be possible with some form of ERC.

Pinky - you left the lens cap of your mind on again.