On Mac's, .pngs automatically export with transparent backgrounds. PC's don't, however. I believe there ways of doing it with either rendering plugins (twilight, podium, vray, etc), or perhaps just adjusting the colors and shadows of the model to white and black and re-exporting the animation frames, to come up with alpha frames for the entire animation. I've not tried it on a film though, just on one frame photos. Chris

Thanks, Al. I understand it better now.

My understanding is that if you export a .png on a Mac, the background comes out transparent. It does not a PC. So perhaps you could export your animation as a series of .pngs from a Mac and then you could put the pngs together into a video, therby getting your video with transparent background. Chris