Hi there,
I have an issue with nanite tessellation on both landscapes and static meshes in both 5.3 and 5.4. Essentially parts of the tessellation are rendered black until you get closer to it and then when you move away they go back to being black silhouettes.
I have tried every nanite setting that I am aware of, tried on both a landscape and a static mesh equivalent of the landscape and tried both 5.3 and 5.4 on different projects.
It happens at both runtime and in the viewport
See the video below of what I am experiencing. This is on a landscape with nanite tesselation enabled.
Does anyone know if this is fixable or just a bug currently with Nanite Tessellation?
Yep, this is a known problem by the devs and it does have workarounds. Essentially, Virtual Shadow Maps try to cache shadow information as much as they can, and since they’re not currently aware of nanite tesselation, they will hold onto old shadow pages that don’t take nanite tesselation into account. When you move close to the geo however, VSM discards the old pages and generates new ones that do account for the nanite geo, but that’s only because you’ve gotten close enough to the surface that VSMs would have made new shadow data anyways.
So basically, VSMs don’t know about nanite tesselation at the moment, and shadow objects like they aren’t tesselated until their pages get refreshed. You can fix it by forcing VSMs to reject history faster and more aggressively, but bear in mind this can seriously damage your frame rate, especially with a lot of lights. I believe 5.4 release has a patch for this, but it’s not in the preview currently.
Thanks for the information - I did manage to solve this shortly after, I un-checked Two-Sided Material which fixed it… Frustratingly this was after trying to solve it for almost a day with no luck and it was simply that…
However, I then needed to duplicate the landscape, move it down, and apply a different two-sided material to then block any light coming from underneath…