Hi @Vallevaar ,
I do not know what you have measured but one thing is sure: there is no free lunch. The concept of slab has more features than before so it won’t be faster. However we expect Strata to adapt to complexity and be the same cost for all legacy shading models.
Optimization is one of the main thing we focus on. Last time we evaluated, we have measured all legacy shading models with strata in games on consoles (older an newer) and we are roughly on par GPU cost wise, sometimes even faster. This is a must to make sure all games can continue to ship. We are still not done with all platforms and uses cases, lots of work remains.
If you use multiple slabs then that is the advanced use case this new framework allows. It is expected to be more expensive according to the number of slab. A single slab can also be more expensive depending on the features you enable on it (MFP lead to SSS, Fuzz, Anisotropy, Haziness, Colored F0/F90).
Custom shading in UE4 I assume is not really existent as a feature. So there is no comparison point. When that is added at some point to Strata, one should be able to implement dead simple shading models.
I could not reproduce any ctrl+z crashes in 5.2 sorry. Could have been fixed by someone (note: there is no Strata material editor, only Strata nodes in the UE5 material editor)