How to set overlapping shapes to add

Hi, in Mocha Pro, I tracked and roto’d an air conditioning pipe with several ducts attached to it. I roto’d
the pipe and the ducts separately. When I rendered the mattes, the pipe and ducts were white, but the spots where their shapes overlapped were black. How do I render the overlaps as additive, so they will render white as well?


Hi @anamorph

How are you rendering the mattes out?

My guess is those layers are turned off and you’re rendering all visible layers. Try making sure you’re rendering every layer you need.

Thanks for the reply. All the layers are on. Here’s what the preview looks like on-screen:


Could this be because all the rotoshapes are on one layer? If so, is here an easy way to move them to separate layers? Thanks.

Oh, definitely it’s because they’re on the same layer.

You can duplicate the layers and delete the shapes you don’t need per layer.

In the future, when shapes overlap on the same layer, the expected behavior is to be a cutout inside of Mocha. If you don’t want that behavior, simply add layers. Hope that helps!


Thanks for that. I tried duplicating the layer and deleting rotoshapes, but I can’t seem to select one rotoshape – they are all grouped into a single mass. What am I missing? Thanks!

You’ll have to use marquee selection under the selection tool and delete the points. It’s not ideal. One layer is treated like a single shape, so you have to delete the offending points.