Frustum Culling

[Dr Dogg]

I am always a little suspicious when frustrum culling becomes an abolsute necesity. Could your data be sorted pre-rendering in such a way as to avoid having to frustum cull so much data anyway?

For example BSP trees or portal rendering. If your data largly is static, BSPs allow rendering without depth-testing.

Perhaps you could use frustum culling but group your data in such a way so that large chunks of data can be culled by one test.

I guess my point is, if you are culling really small groups of objects, you may be wasting your time.

[roffe]

Originally posted by Dr Dogg:
I am always a little suspicious when frustrum culling becomes an abolsute necesity.

Why? If you are not culling your space partioning structure against a viewing volume, how are you doing your gross culling?
Unless you want to pre-calculate a lot(PVS).

If your data largly is static, BSPs allow rendering without depth-testing.

If you use bsps with the intent to not use depth-testing you need to split every polygon that crosses splitting planes. Studies have shown that this will severly increase your polygon count. It could be good to manage transparent surfaces though.

When talking about frustum culling and performance in general, I'd like to recommend this document about batching from NVIDIA. http://developer.nvidia.com/docs/IO/...BatchBatch.pdf


[This message has been edited by roffe (edited 02-03-2004).]