Crop "spilling" video to not show up on other projector

[paralion]

So, I have 4 x 4K projections, they are all rear projections, creating a Room that has 4 video walls.
In Arena, may "Output monitor" is like this:
https://docs.google.com/presentation/d/ ... sp=sharing

Each Quarter of th Screen represents one wall.

Lets say I have a clip on the FRONT wall. If I move it a bit down, it will "spill down" to the BACK wall. I would like to "crop" that part way, but I dont know how? Dont really understand the crop effect, or is there another method?

I know this might be overcomplicated to explain by writing, but well, at least I tried...

[Zoltán]

Try output masks: https://resolume.com/support/en/output- ... on#masking