Rectangular Light Affecting Objects Behind It in UE5 – Need Help

Development Rendering
, ,
1

Hello guys,

I’m currently working on a Gears of War 5 fan art scene in Unreal 5.1 and have run into a lighting issue that I haven’t been able to solve for quite some time. For some reason, my rectangular light is affecting objects that are positioned behind it, which shouldn’t be happening.

Feedback_07
Feedback_071849×2081 4.78 MB

Here’s what I’ve tried so far:

  1. Toggled Lumen on and off

  2. Replaced the light with a simple emissive plane — the issue remained

  3. I tried changing the lighting channels, but it didn’t help.

  4. Recreated the scene from scratch without importing any textures — the light worked correctly. However, after applying textures again, the issue reappeared.

  5. I tried turning off all other lights and leaving only this one for the flare.

  6. I enabled two-sided in the material and flipped the normals of the objects behind the light source.

  7. I also tried switching to a different light source, like a point light.

This makes me think it might be related to optimization or memory limits — possibly something like the texture streaming pool size. Unfortunately, I haven’t been able to find a solution online or through experimentation.

Here’s a video that clearly shows the issue:
:backhand_index_pointing_right: https://www.youtube.com/watch?v=Gezzw3xixrs&ab_channel=AlexFilvet

I’d be really grateful if you could take a look or point me in the right direction to fix this.

Kind regards,
Oleksandr Filatov

2

Looks like some sort of screenspace effect. Either from Lumen or screenspace reflections. If you put a non-reflective material on that wall, does it still happen? If you disable Bloom, does it still happen?

1 Like
3

I found the solution: Disabling SSR and Lumen’s diffuse indirect lighting did the trick:
r.SSR.Quality 0
r.Lumen.DiffuseIndirect.Allow 0

4

This disables lumen’s GI, just so you’re aware, so your scene will have no GI unless you bake it.