Probably a dumb question, but what format do I have to render a movie in to get the background invisible? I already have Premul and RBGA enabled, but I just cannot figure it out.
TGA(32bit: 8bitx4channel) and PNG supports alpha.
I don’t know of a movie format that supports alpha. Their is probably one I don’t know. the best thing to do is render an image sequence to a format that supports alpha and use that sequence to do your composting, then when you get it the way you want render to a movie format.
Render the individual frames to individual files in a format that supports Alpha. Then, make sure that you have requested that the Alpha information be included.
This is important for many reasons… one of which is that the process is easily restartable. If your kitten starts playing with the power-cord when your render is 99% finished, and you don’t manage to get to the kitten in time, then you can resume where you left off: all the other frames are still there.
You render to a movie-format as the very last step.
Thanks for all the help.