Currently groom always overlaps fogs (volumetric clouds) even if it’s behind it.
The example is below - to the left there is the same groom in the distance, it’s behind the cloud but you can see it clearly like cloud is not there.
This question is also important because there is VDB rendering plugin that uses volumetric clouds as it’s base and the solution would help to blend groom better in the scene with VDB.
Already tried modes from r.HairStrands.ComposeAfterTranslucency - I guess it works for translucent materials and not fogs.
Reported bug to Unreal: ## Case # 00513275: Groom render sorting issue with fogs (volumetric clouds) has been received
It’s imporant issue for cinematic pipeline since Volumetric Clouds are currently one of the best ways to render VDB and there is no solution for mixing with groom.
