Matte shape aliasing

Show me grace. I’ve been spending a lot of time in mocha, but I’m pretty new. But I have done a lot of tutorial binging and some broadcast work with Mocha Pro.

I’ve Googled and watched some rotoscoping tutorials from the Videos section, but no answer yet.

Also, am I a dunce, or can you not search the forums? I only see the general site search.


My problem. I had to give up on a removal request, because I was getting aliasing with my shape used for masking / subtract blend mode. I had to do a blur instead. : (

The example below is a foreground matte used over a clean plate removal / replacement.

I tracked the coffee cup. Set up a clean plate replacement of the heat slip. I then intended to roto and mask the fingers back on top.

But I kept getting jagged edges. There doesn’t seem to be much of a fade at all. What is blurry there is original camera motion blur.

The cleanplate is an uncompressed PNG.


I appreciate for the help and apologize for the newbie question.



I’d simply remove that whole section under the finger and composite it back over the top in a compositing program. It looks like mocha is having a hard time replacing that edge nicely. This is not a roto error on your part, but there’s absolutely a solution. Compositing it with a feathered matte, or a matte rendered with motion blur, in nuke or AE, will solve this issue for you.