this is something I have done years ago though I cannot remember how. Perhaps a small kick in the right direction will solve it for me (and save me additional time). ;-)
I have a stock footage of a curtain opening and going to the sides. The animation is followed by black and white clip (for the alpha). I separated it the two clips and put the animation on v1, the black and white on V2 in a separate sequence (curtain). What do I have to do to apply the b/w mask to the animation? I am messing with keying, but nothing works.
My intention is to use the "curtain" sequence in a "master" sequence to always reveal image slideshows I am working on (12 slideshows with 10 images each, at each set beginning the curtain opening).
I am on CC.
Thanks Alex. Not sure what nest is but the curtain sequence has the animation with the track mate on v1, the b/w footage on v2. Once I put the curtain sequence to my master sequence, it works as intended. The only thing I had to set in the track matte key is to switch it to Luma.