You need to render your movie with an alpha channel. First double check to make sure you have a transparent background by clicking on the “checkerboard” underneath the Comp Work area, if you see the checkerboard when you click it, you have transparency.
So press “shift+cntl+/” to add your comp to the render queue, choose your render settings, then choose your output module. You will need to choose one that supports an alpha channel. Quicktime-Animation is a good one, in that it’s lossless and supports an alpha(though it delivers massively sized files). To activate the alpha go to Video Output > Channels and change it from the default of “RGB” to “RGB + Alpha” Now render away.
Johnny Cuevas, Editor
Thinkck.com
“I have not failed 700 times. I have succeeded in proving that those 700 ways will not work. When I have eliminated the ways that will not work, I will find the way that will work.”
—THOMAS EDISON on inventing the light bulb.