IBM Animation?
It's relatively unlimited, or just limited by available memory. 🙂 In
other words, they let you define the horizontal and vertical resolution,
and the pixel aspect ratio. Rendering is 24 bits plus 8 bits of alpha
that's processed at the same time. So, for example, you can generate the
alpha planes of your object at the same time as the 24 bit RGB, then use
the alpha data later in the "video post" part of the program, for special
effects, etc.