What is the purpose of SRP Batcher?

I am using frame debugging in order to optimize my upcoming game. I don't really understand the idea behind the SRP Batcher. I want to reduce the amount of batches and, although, it appears that many elements are combined in a batch, that is not the case as seen from the Frame Debugger.



So here in the first SRP Batch I have at the moment only 7 batches, however when I click the next SRP Batch the amount jumps to 21. As if the objects are rendered separately. But why is it called a SRP Batcher then? What does it do?

 

I don't think the Batches stat is as important if you're using the SRP batcher.

 

Yeah that's true
Been experimenting with SRP Batcher since it's came out and I've noticed that when it's enabled stats are somewhat wrong but performance is better so you should not care about stats when using it just look at FPS

 

Necroing this for others who are trying to find information on the subject. In scenes with lots of terrain trees grass et cetera, SRP Batcher can in fact be up to 3x slower than traditional GPU instancing in the render thread. If you're drawing several thousand pieces of foliage with similar materials and meshes or some similar situation the SRP batcher doesn't stand a chance against instancing.

It would really be the optimum situation if it were possible to disable or enable SRP batcher on a per material/shader basis without resorting to shader witchcraft by calling SRP incompatible var.

The assumption that SRP is faster in all situations is plainly incorrect, i don't doubt it's commonly faster for a varied scene but situations where you're using thousands of identical meshes instancing really is quite a bit faster (real use case scene, on a 8700k render thread hits 20ms with SRP batcher, 5.6ms with a combination of static and GPU instancing. This is a huge difference).

 

All kinds of batching all have their own respective use-cases and are not silver bullets.
https://forum.unity.com/threads/srp-batcher-and-gpu-instancing.833362/#post-5521216

 

agreed - a toggle batch/instance would be easier than writing boiler plate c#. i wonder if URP 10.2 new particle system mesh intancing can be used for that.