GUI always covering screen - how to make use of it?

Questions & Answers
1

In my mobile game, I have scaleforms GUI covering 1/3 of the screen completely all the time. Now I think, why should I render everything behind this area at all?

Like this:

Can I somehow make this area to work along with occlusion culling?

Or maybe, faster way is to use 1 Camera to render GUI, and 2nd Camera render-to-texture and then show on that smaller portion of the screen? This way, I’ll have more vision, but would it hurt performance?

Basically, my question is - how could I use this all-the-time covered area affectively to aid either performance or visuals? Any recommendations?

2

You don’t need any rendertextures, just two cameras. Set the viewport rect of the second camera so it covers part of the screen.