I need a free animation program that can take a few 5-10 frame looping animations and mask each one with a moving vector or hand drawn raster (either one, or just erasure even, but preferably vector masks) and layer them. Any OS, preferably Windows XP. Any ideas?
Basically, I need something for weather forecasts for our student-run TV station; I figure I can make a layer of looping cloud animation, a layer of looping rain, a layer of snowflakes, etc. all at 50% opacity or so with some gaps between particles over a base image and then just animate a mask on them or animate an outline for them.