2 replies to this topic

[jdub]

I was wondering if there's a significant performance advantage to batching together the rendering of scene objects which use the same shader?

[Jason Z]

There is potentially a performance advantage. In general you can say that fewer draw calls should be better, but that all depends on what else is going on in your rendered scene. There isn't a straight answer for these type of questions really, you have to profile your application and see what works best in a given circumstance.

[Nik02]

Generally speaking, the fewer state changes, the better. Of course, if you use heavy logic to implement the batching itself, at some point it ceases to be worthwhile.

If you have a strong GPU but weak CPU (rough measures, I know), you likely benefit more from batching than with a system with strong CPU but relatively weak GPU. Each state change will consume CPU time, even though the setup time on the GPU hardware would be very fast.

Edited by Nik02, 30 November 2012 - 06:04 AM.