Use 3d-objects as matte

Hello again,

We are doing a virtual production project where we combine Unreal environments on led with an extra augmented layer on top coming from Notch. There is some geometry in Unreal that I would like to use as a mask for the augmented layer that is coming from Notch. I have the 3d-objects loaded in Notch, but can’t seem to find a way to make them matte objects. How should I approach this?

What comes to mind, but seems like a workaround to me, is rendering this object in a render layer and then composite/channel boolean this with the main output, thus extracting it in post fx.

Thanks for your time!

Marc

Never mind, figured something out. I put the ‘matte object’ in a render layer that is not set to deferred rendering. I set the material to transparant and transparency (although ghosted out) and brightness to 0. Then it subtracts the matte object from the alpha of the main scene.

So not by knowledge, but I came to a solution. Although I wish I could understand why these things work, and not just get there by trying 500 things until something works. :upside_down_face:

Thanks for sharing your solution!

As far as I can see my method would be to firstly add a render to texture node both the notch augmented sequence and the unreal 3D models and then composite them as required