problem with null object and layer
by Franz Zander on Jun 20, 2011 at 10:15:18 pm
i hope this is the right forum to post my problem.
ok. what i have are two layer. both are the same layer but the one is only black & white. the other one is the original layer. so, i did 5 or 6 motion trackings in the color layer and combined them with null objects. two layer, one black & white, one colorfull wich has 6 motion trackings and last but not least 6 null objects where every null object is linked with one specific motion track.
my goal was it to make masks in every null object. these masks should follow the motion track and should include the colorfull layer parts. out of the masks, better said the solid, is the black & white layer.
the idea was to have a black & white video where special colorfull parts occure in foreground.
my problem is, that i dont get the combination between mask & colorfull layer. either i have a colorfull or colorless video. i put the black & white footage at the lowest, above is the colorfull layer. the masks are in the "substract" & inverted modus.
what is wrong? did i do a mistake or is the idea false?
Re: problem with null object and layer by Steve Renard on Jun 21, 2011 at 4:05:52 am
If I understand you correctly, you want to have a B&W video with a few bits of color in various places. First question: Is it always the same color? If so, why not use the "leave color" effect?
If it's not always the same color (or group of colors), it sounds like you're on the right track but have missed a step, perhaps. From what you said, it sounds like either you put the masks on the null objects themselves, or on either the B&W or the color layer. To achieve what you're looking for, I think you need to do a series of six (one per null) separate solid layers with masks on them, link each to one of the null objects, and then make six copies of your color footage and use each masked solid as an alpha matte.
Be warned, though, that unless this is an extremely short shot, or you have a high tolerance for drift in the masked areas (or both), it's unlikely that you'll be able to get a good result from this technique. For a really tight mask in this situation, you're probably looking at using the Roto Brush, at the very least, if not doing manual rotoscoping, if you want to stay within AE. You might be able to get better results through Mocha for AE (ships with CS5) but my experience has been so-so with that too.
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