Area Masking on layers

Hi everyone

I am new here, this is my first question.

I like to project with 1 beamer on several display surfaces(4-7) for my shows. Normally I have one layer covering all surfaces together. what I would like to do is “black out” the areas where no screen is positioned.
Also a similar question arises when I want to project on an elliptical shape or a triangle.

Any ideas? I could not find an answer by myself for the problem below, if one exists id be thankful for any pointer in the right direction…

thx
m

Make more layers with Make some extra layers. Set the source to constant color, make the color black. Go to your layer crop thingy, set it to quad. Reply this step until you see just your screen.

Then, what I do for the parts that I do want tot see, is make a new layer for your screens. Don’t slide your opacity open, it would show on your main output. Then make some more layers, 5 of you have 5 screens, set the source to the layer you just created for your 5 screens. Do the same quad thing with these screens.

Example attached. Weg layers are the ones that black out the parts where there are no screens. Scherm layers are the screens. Portrait dinges is the layer used for the screens (scherm layer). Mix is obviously the mix of the main layers…

Link to file: https://drive.google.com/file/d/1aVzlNrDxQlPqPfnmPAg76kKxecrkhAAJ/view?usp=sharing

This youtube vid helped me out a lot: https://www.youtube.com/watch?v=mxZdreZKsQ4