need help: rotoscoping motion-tracked material

[schorsch]

Hello!
So this is my first post here, and I'm kinda ashamed to bother you with a rather silly question like the following one :eyeRoll

I'm working on a tiny little project for which I shot some footage where an actor moves from left to right. So I tracked the camera movement with mocha and added the tracking footage to a text-comp which I want to be in the background. Now I need the actor to hide the sign when he moves over/in it.

I tried drawing masks but I keep getting a strange problem where the mask only affects the line of tracking points, but not the whole text-comp I want to be behind the actor. I don't know how to solve this problem myself so any piece of advice is highly appreciated :)

Here are some screenshots to make my point clearer:

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this is what I want to do: hiding the sign behind the actors head while he moves over it.


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and that's what it ends up like. the layer modes don't seem to change anything, all I get is a buggy piece of masked out sign along the "motion tracking points line". I really don't know what I could try to fix this :(



thanks in advance!

[chrisg]

Hi schorsch,

The problem is that the mask is being effected by the tracker scaling, so it is scaling down. I would create a new solid a layer above, and mask that layer, then use an alpha or alpha inverted track matte. The mask won't move with the tracked layer, and you will have to animate it.

[schorsch]

ahhh thanks a ton! solved it by following your advice :)