Mask to Alpha w/blending (Composition by scalf)

Author: scalf
License: Public Domain
Date: 2011.07.12
Compatibility: 10.6
Required plugins:

This composition illustrates how to mask a piece of media behind the black values of a picture, leaving the deeper layer to shine through the white values of the mask.

Hopefully the pictures will stay with the file.


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scalf's picture
Re: Mask to Alpha w/blending (Composition by scalf)

I could not upload the media associated with the file.

Check here for it all in a zip where everything works.

cybero's picture
Re: Mask to Alpha w/blending (Composition by scalf)

Maybe a dumb question, but are both the movie files in the zip meant to be black empty space? I wouldn't have thought so from their names :-) .

Upon some further experimentation, although movie files don't work reliably within the setup you posted, plain image files do work just fine.

gabemott's picture
Re: Mask to Alpha w/blending (Composition by scalf)

I found "yellow buzz cube" empty black but "4 Grid Thick White" was a cool animated grid. I had to change the paths to media/ and I dropped in a movie to replace the yellow buzz and it worked. The house mask seemed to scale down when I held the space bar. Thanks for posting.

scalf's picture
Re: Mask to Alpha w/blending (Composition by scalf)

Yeah, sorry for the confusion with the media. They were specific dimensions,and seemed to not stick with it. Also, a different video may adjust the perspective; so it goes.

But the bulk of it is there.

And you are right, they are not supposed to be black ha. Really, I chose those to chow movement behind the image, as well as how to correctly crop the images.

Hopefully you can find it useful!