I've pulled a key on some green screen footage and want to output a matte from that key as a file or output a file with embedded alpha. Can't for the life of me figure this out. Any help would be appreciated.
What module did you use to create the key?
In action its easy to output a matte, go to Output, select your current output, then change the type to media matte.
In the Modular Keyer, select your key result node, then change viewing from result to matte. Now you can process out a matte.
Hi. What Moody said will get you the FILL and Matte on to the desktop (source area). The software "buttons" are to the right of the MEDIA menu (center right) in the ACTION module.
Onced the FILL and MATTE have been rendered out to the desktop (source area), save them to a CLIP LIBRARY. Once in the CLIP LIBRARY. Select the FILL, hold ALT and select the MATTE (both should now be border highlighted in YELLOW). Then hit the EXPORT IMAGE button. Once in the EXPORT IMAGE menu, select RGBA (as opposed to only RGB), select QUICKTIME (from the list of QT, Targa, TIFF, DPX, etc.), select your compression (I normally export UNCOMPRESSED), choose the LINUX file folder for your destination (TMP, EXPORT, make one that's job specific, etc.), and lastly hit EXPORT (or ADD TO QUEUE AND EXPORT... I'm not in front of a ststem at the moment). Once the file is done exporting, you can open it in After Effects, and it should come in as "millions of colors plus, I think the "plus" indicates and embedded alpha. That should about do it. Good luck. -TomT