I'm trying to insert a keyed video in front of a background in the Video Sequence Editor. The video is keyed in the compositor in a separate scene. Then I try to alpha over the scene in front of a background but it won't blend over properly.

Keyed scene in Video Sequence Editor

It somehow can't handle the areas which aren't completely transparent. How can I fix that?

Here is the blender project: keying.zip It's just an example though and I would like to use the same technique in projects without static background as well.

Thank you very much ;)


1 Answer 1


To use the alpha output of the compositor in the VSE first convert the alpha to premultiply. If your alpha channel isn't already an integral part of the image data you can mix it in using a Set Alpha node.

set alpha node into alpha convert node


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