Talks And Demos: Unreal Fest 2025: Game Engines and shader struggling: UE's solution to the problem

Learn how to reduce shader stuttering by setting up a test environment, capturing shader data, and applying PSO optimizations for smoother gameplay.

https://dev.epicgames.com/community/learning/talks-and-demos/VEkM/unreal-engine-unreal-fest-2025-game-engines-and-shader-struggling-ue-s-solution-to-the-problem

Hi, thanks for your awesome tutorial!

There is a minor thing that still bothers me in the module-3 video. There are some cvars you set:

r.ShaderPipelineCache.ExcludePreCachePSO=1
r.PSOPrecache.ProxyCreationWhenPSOReady=1

However, according to the official reference, when the r.PSOPrecache.ProxyCreationWhenPSOReady is 1 (which is the default value), the proxy creation behavior will depend on the r.PSOPrecache.ProxyCreationDelayStrategy, and the default value of the latter one is 0, which means it will delay creation until PSOs are ready. Perhaps you mean to set r.PSOPrecache.ProxyCreationDelayStrategy=1?

Besides that, IIRC, maybe we need to r.PSOPrecache.Validation to non-zero make sure r.ShaderPipelineCache.ExcludePreCachePSO takes effect?