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sporadic
09-05-2005, 06:47 PM
I have two image sequences, and I need to use the alpha channel of the one to matte out a portion of the other. I'm basically an AE newbie, and haven't been able to figure out how to do this in the docs.

Can anyone help?

Thanks!
Vympel
09-05-2005, 07:06 PM
look at

http://forums.cgsociety.org/showthread.php?t=268040
Khalor
09-06-2005, 05:52 AM
One change from the above thread: if you are using the Alpha channel from the seperate footage (as in, not a greyscale representation of the alpha channel, but a true seperate channel) you'll need to use the 'Alpha matte' track matte mode, instead of Luma matte.

Hope that helps! :thumbsup:
sporadic
09-06-2005, 01:01 PM
Thanks, Khalor, that was the tip I needed. I only have the footage with the alpha channel, no greyscale alpha separately. The thread Vympel mentioned pointed out a lot of good stuff I wasn't real clear on though, so that is really useful too.

Thanks!
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09-06-2005, 01:01 PM
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