# Strange Noise in Shadows Cast on Foliage

**URL:** <https://forums.unrealengine.com/t/strange-noise-in-shadows-cast-on-foliage/2435427>\
**Category:** World Creation\
**Tags:** Shadows, unreal-engine, Foliage, Lighting\
**Created:** [April 2, 2025, 2:16am UTC](https://forums.unrealengine.com/t/strange-noise-in-shadows-cast-on-foliage/2435427 "2025-04-02T02:16:40Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![luanzerabr](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@luanzerabr](https://forums.unrealengine.com/u/luanzerabr)\
**Post date:** [April 2, 2025, 2:16am UTC](https://forums.unrealengine.com/t/strange-noise-in-shadows-cast-on-foliage/2435427/1 "2025-04-02T02:16:40Z")

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Hello, thank you in advance for your attention!

I’m working on an Archviz project in Unreal Engine 5.5.4. Everything was going well until I started populating the scene with vegetation like grass, trees, etc., all imported from FAB.  
When I began placing the trees after painting the grass using Foliage Painting, I noticed this bizarre noise in the shadows cast over the grass, and I simply can’t remove it or debug what’s causing it. I’ve already changed the lighting, anti-aliasing, and the grass material.  
There are also other parts of the scene where strange flickering is happening, like on the stair railing of the house.

I suspect it’s some kind of Lumen or Nanite bug, but I don’t know how to fix it. Has anyone seen something like this before?

Here are links to some footage I took:  
[Vídeo 01](https://youtu.be/ENt3XtjTrjU)  
[Video 02](https://youtu.be/Z-7fPxDscsA)

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**Author:** ![Hirk](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Hirk](https://forums.unrealengine.com/u/Hirk)\
**Post date:** [April 5, 2025, 9:42pm UTC](https://forums.unrealengine.com/t/strange-noise-in-shadows-cast-on-foliage/2435427/2 "2025-04-05T21:42:52Z")

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Here are some notes I took while watching YouTube videos about Unreal Engine. Maybe there’s something there that will help you.

 ![FoliageIssues](https://d3kjluh73b9h9o.cloudfront.net/original/4X/3/7/0/3704efd104ce834765d1e2f27295724b358def6d.jpeg)

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**Author:** ![pansee001](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@pansee001](https://forums.unrealengine.com/u/pansee001)\
**Post date:** [April 19, 2025, 8:10pm UTC](https://forums.unrealengine.com/t/strange-noise-in-shadows-cast-on-foliage/2435427/3 "2025-04-19T20:10:20Z")

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Hi there,

I’ve seen a good post on this earlier.  
[https://forums.unrealengine.com/t/foliage-has-a-shadow-noise-grain-how-to-fix-it/727330/36](https://forums.unrealengine.com/t/foliage-has-a-shadow-noise-grain-how-to-fix-it/727330)

It likely has something to do with virtual shadow maps and raytracing combined with soft shadows.

You can check it by setting your sun angle to 0 in your directional light.

Potential fix (for now) is to increase the rays per pixel on raytracing and messing around with the sun angle.

That worked for me at least.