VR Foliage / Grass noise needing to be reduced

Development Platform & Builds XR Development
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1

Hi all,

UE5.4.4
Nanite On
Lumen On
Shadow maps On

We have an issue with a project we are working on in which the foliage / grass creates a noise / haze effect (see video). The effect does improve with Frameweight being reduced but still present (even if set to 0)

Other meshes (like buildings etc) are fine it seems to just be an issue with Foliage and Grass objects.

Any ideas why this is happening / name of the issue so we can further research it / or ideally a solution would be amazing!

Found this post which has the same issue but increasing the r.Nanite.MaxPixelsPerEdge didnt fix it.

2

We had the same problem, but never fully fixed it.
However, we tried changing antialiasing method and found that TAA gave a better result (for our use case). We also tried to change the computers GPU to a RTX4090, which reduced this drastically.
(Our VR project was not standalone)

3

Ok thats a shame you weren’t able to fix fully but does seem to be an issue with more fine detail foliage tree’s.

We are using TAA but did find TSR did give a slightly better result but at a cost to performance so not really an option for us.

We found the Directional light source angle helped reducing it to 0 and reducing the frame weight to under 0.5 reduces the issue.