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Alpha Mattes

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Andrew WagstaffAlpha Mattes
by on Dec 9, 2010 at 8:32:50 pm

Could anyone tell me how you get an alpha matte to work ive got two video files a background video and a 3D character for a second video ive already rendered a separate alpha from my 3D software but i cant get it to work

ive looked around and i cant find any tutorials that deal with alphas on thier own

any help would be great

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Dave LaRondeRe: Alpha Mattes
by on Dec 9, 2010 at 9:51:52 pm

Did it come out as a B&W image where black=0% opacity, and white=100% opacity? The white part is the alpha channel, and you use it as a LUMA matte and not an alpha matte.

If you mean something else, did you render the image in a codec that supports alpha channels, like Quicktime's Animation or PNG codecs? You typically have to make sure the it's set up to include alpha channels.

If you're on a Windows box and don't use quicktime, you're on your own as far as codec selection goes.

Dave LaRonde
Sr. Promotion Producer
KCRG-TV (ABC) Cedar Rapids, IA

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Andrew WagstaffRe: Alpha Mattes
by on Dec 9, 2010 at 10:04:53 pm

Thankyou it was a luma mat

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