I’m having an issue with light bleed in interiors of buildings that seemingly disappears as I get closer to the area and reappears when I move further away. [Edit] This issue existed prior to upgrading the project to UE5 so I don’t believe this is a UE5/Lumen issue.
Project Details:
Lumen is enabled
Moveable directional light
No light source within the building
[Edit] All roofs/walls/etc. are separate, solid meshes.
[Edit] Walls/roofs/etc. are 20 cm thick
What We’ve Tried:
Adjusting shadow bias (Setting shadow bias to 0 fixes the light bleed, but causes artifacts to appear elsewhere in the world)
Adjusting shadow filter sharpness
Adjusting dynamic shadow distance
Adjusting cascade shadows and contact shadows
[Edit] A boxed light blocker around the building has zero effect
[Edit] Adjusting Lumen Scene Detail and Max Trace Distance on post process settings has no effect
Below are screenshots from a distance and in close-proximity to the far corner seen in the distant image.
Try changing shadow slope bias in Directional light (also maybe Shadow resolution scale), you can also try changing Shadow bias but be warned setting it too low causes some strange lines to appear on objects.
We adjusted pretty much every lighting setting we have and seemingly had it fixed for a week or so, but now it’s back. Wish I had a definitive answer for you, but it seems like it’s just tweaking every little thing until it looks decent.
I had a similar issue today, I found that making the light blocker mesh around my room have solid 10cm thick walls fixed the issue (it wasn’t working to block light when it was a simple outer shell).
I fixed the same issue in my scene by going into my Direct Light/Advanced/Shadow Bias.
It was set to 0.5. I changed it to zero and the leaking disappeared.
If you create a box as a light blocker, try to invert the normals. Saver is maybe to create a thick shell as a blocker box. Unfortunately not very handy.
In my case, I was able to rectify this issue by setting Shadow Slope Bias to zero and maxing out Contact Shadow Length in the Directional Light; hopefully this helps someone that happens across this thread.
Hi, I’m seeing the same issue at distance, and like you have tried many of the suggestions. Were you able to find anything that helps which isn’t setting shadow bias to zero?