• Adobe After Effects

  How to add/subtract mask to/from alpha channel?

  Posted by Jacek Skro on November 16, 2006 at 4:53 pm

  Hello all,

  I work with After some time, but still I don’t discover simple way to add/subtract mask shape to/from alpha channel. Normally masks “cut-outs” whole layer, but I want to do some operationson existing alpha channel with my drawn mask.
  Of course this can be done by making second layer, draw mask on it and setting it as an Track Matte, but this approach doubles my layers count – of course I can still precompose this both layers, and get one layer again, but I think that there is possible one-layer way. Any one know how to make this?

  I try to fill mask with alpha channel white or black (it would be like an equivalent to add or subtract operators), but unfortunately Fill effect works only on RGB not on Alpha channel.

  Regards

  Jacek Skro replied 19 years, 5 months ago 1 Member · 0 Replies
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