Export / Render Out with Alpha Channel

Sidecar2 wrote on 8/19/2009, 12:52 PM

Goal is to render out a multi track sequence of objects and have the output file include an alpha channel so they can be burned over a background video later using a different NLE.

I tried outputting with Debugmode Frameserver using PNG and the output didn't have an alpha.

I'm now trying an uncompressed QuickTime. Working 1080i.

Any other formats that will include the alpha. I

I understand it has to render out at 32 bit (8 each for RGB and 8 for the alpha).

Is there a switch somewhere that turns that 32 bit on or do I just use Quicktime for output, assuming that works?

Thanks.

Comments

TheHappyFriar wrote on 8/19/2009, 1:44 PM

there's only an alpha rendered if there's an actual alpha in the project. IE if you put a black/white/whatever solid color on the lowest track for the whole project, no alpha, because you have the solid color. If you have nothing in the background except the "black" nothing vegas puts there, an alpha will be there.

QT PNG is easyiest imho: less files vs individual PNG render, and faster.

Laurence wrote on 8/19/2009, 2:17 PM

Another vote for Quicktime PNG here. If anyone has a better solution, let us know, but so far Quicktime PNG is the best one I know of. Way smaller than uncompressed and every bit as good quality.