CompuServe Messages

John, Thanks for the reply. Your explanation is correct, the problem I have however is that the Foreground objects should not have to be rendered over black, If there is black there in the Foreground Alpha image it shouldn't matter what was there in the F image. Say for instance I render an animation on a color backround that I decide I don't like, If I saved the Alpha images is should be a trivial matter to recomposite over another background, but it doesn't seem to work if there is anything BUT black as the original background of the F image. This is how it seems at least, and thats inconsistant with the concept of alpha compositing in any other package I've used. My current application is this: I've digitized many seconds of video of a girl standing in front of a white background. She is supposed to be mapped on torn paper as the top layer of a heavily composited scene. So I paint a torn edge matte just slightly larger than her outline slap her in the forground layer using the matte to "disappear" all the other white around her RIGHT? NO, unless I first composite her over black in Adpro it doesn't work. And thats an extra step I'd rather not take. What am I doing wrong? Thanks in advance. Mark C.