After going from 5.6 to 5.7 my directional light “shines” through my HISMs when using volumetric fog. This only happens when the directional light is moving (UDS animating day/night here). It seems to worsen when I move further away from the instanced meshes.
Here are GIFs showing the difference between first 5.6 and then 5.7:
Are there maybe changes to HISMs that happened in the backend in 5.7? Lumen Hardware, Nanite and VSMs are in use.
If anybody experienced something similar I would love to hear about it.
That’s a quite specific glitch, almost looks like your instanced mesh are dissappearing when creating distance. As a quick test, I would convert some of them to regular static meshes, and see if the behaviour changes.
As for possible related changes between 5.6 and 5.7, checking around the community, other users have reported that the directional setting for VSM masks is now set to enabled by default, which could create a potential conflict on how volumetric light/fog interacts with your HISMs.
To revert that back to how it was in 5.6, open the console and input r.Shadow.Virtual.UseReceiverMaskDirectional 0, then test your scene again.
