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Lumen + Grass

I wonder if anyone has any tips when working with Lumen and Landscape Grass?
The grass loads extremely slow and doesn’t look very good with Lumen.
I wonder if there’s a way to tell Lumen to ignore it?

Hi!
The post is 18 days old but might help you or anyone else if they find it.
The loading slow part im not sure about, might be many factors( hardware,density,texture size, landscape size, visible distance) To make it look better:
Landscape’s themselves do not contribute to lumen global illumination, but when you use a nanite mesh floor for example and place grass on it you start seeing flickering gi, general shadow noise.
What i did to improve my grass is disable affect distance field lighting on my foliage objects.
Which can be done on the object itself or from the foliage tool under instance settings.
Also i believe that the lumen effect on non nanite meshes are in screen space.( someone correct me if im wrong) and what helped with the noise was using the console command:
r.Lumen.ScreenProbeGather.Temporal.DistanceThreshold
i believe the standard value is 30. but i just pushed it out to a 1000 in a forrest test scene.
so it ended up being, r.Lumen.ScreenProbeGather.Temporal.DistanceThreshold 1000
Try that and see if it helps :slight_smile:

I m using grass for a lawn on my project and it is working fine, though I have not taken it into render queue and rendered it for the final output.

I think the number of instances and your GPU VRAM matters as well. How much VRAM do you have?

Mine is not looking bad when it comes to the lumen.

I will try the threshold command and see if it changes anything