Ok my project has 5 .mov files exported from FCP using compressor with "animation, millions+" settings from FCP using compressor . Each .mov is a edited layer with blank spaces revealing below layers that are rendered out with alpha channel.
From that I want to build separate comps in AE apply effects, transitions and, fine tune in AE. Then I wanted to compose those comps in a final comp.
My problem is as a test of the alphas before I started, the alphas were not working in AE, I checked them in FCP they work perfect.
What I've done so far:
1- Interoperate Footage settings were correct (i thought), alpha straight-unmatted
2- tried a bunch different mode combos even though it should work without that, but no help
3- the only way I could get it to work was to use a "Difference Matt" effect with difference layers set to none and all other settings to zero.
This seems to work but I know its probably not the best way to do this.
I don't know about using Compressor to make the Alpha-channeled qt's. What happens if you export from FCP using quicktime conversion?
I'll take your word for it that you double-checked the footage for transparency in FCP. I assume you:
1) imported the footage into an FCP project
2) set the fcp viewers to show the checkerboard background that indicates transparency
3) added the clips to an FCP edit timeline and
4) saw the checkerboard pattern behind the clips
I won't ask why you chose to use FCP's lousy chroma keyer instead of keying in AE. I guess you have your reasons.
Sr. Promotion Producer
KCRG-TV (ABC) Cedar Rapids, IA