A few questions about GZDoom clipper

[Darkcrafter]

I got a couple of large maps in development that I believe clipper is unwanted and does bad job, creating excessive work for CPU, like that MAP15 entirely made out of big 3D floors: viewtopic.php?t=76565

1. Is there a way to disable the geometry clipper entirely for certain maps?
2. Is there a way to make clipper operating only in certain sectors like convex ones, more precisely the bounding sector(s) that outline the whole map area where floor and ceiling heights are the same (to show the engine it's a skybox zone).

[dpJudas]

1. GZDoom doesn't use a geometry clipper. I assume you mean the clipper that is used to determine the potential visible set (PVS). Yes, you can "disable" it - here's a branch with the changes showing you how. Note that the skybox and portals stopped rendering when you do such a thing. That's because it now doesn't know that a sky is visible.

2. I don't know what you mean. Probably not. You'd have to write a new clipper for what you are trying to do. That's part of the challenge of going "BSP less". Good luck.

[Darkcrafter]

Thank you for clarification, I didn't know it would have been that hard to do, sorry.

Under 2 I meant: inside that outlined area the pvs determination wouldn't work (the gameing area) and only work inside that big square shaped sector (where floor and ceiling heights are same) to stop skybox rendering twice.

[Graf Zahl]

skybox rendering is not a performance issue. The same skybox will never be rendered more than once, even if you can see it in different parts of the map.
During map traversal all linedefs where a skybox appears are collected, merged into one portal and then get rendered in one go.

[Darkcrafter]

skybox rendering is not a performance issue. The same skybox will never be rendered more than once, even if you can see it in different parts of the map.
During map traversal all linedefs where a skybox appears are collected, merged into one portal and then get rendered in one go.

Good to know. Then there are maps with multiple gaming areas which I'd also like to go without PVS.