Combine multiple Quad' materials into one material

Hey there!

Simple question, I think: I have a 2D scene with several transparent quads, some of them overlapping with each other (resulting in less transparent parts). I want them not to show overlapping and instead be one transparent layer.

That's why I tried to use a renderTexture on a camera (rendering all the quads, but without transparency) and put that into a new fullscreen quad with the transparent material which is seen by a new camera (rendering to game view).

The problem here: I can't grasp how to use renderTexture right. The aspect ratio always seems to be 1:1 and my app is targeted to Android, so most of the time it will be 16:9.

Is there a way to fix this or another approach that fits this problem better?

Thanks for your time! RyFridge