Can't Get Indirect Lighting To Work

Hi Guys,

I’m quite new to lighting in Unreal, so I’ve not got a clue what’s happening with my lighting (see attached image). I’m trying to get my garage interior to be lit purely through the windows, but I’m getting some strange artifacts.

Some additional Info:

  • Light maps are 512
  • All lighting is static
  • There is invisible cubes behind the mesh to stop light from bleeding through
  • Scene has light mass importance volume

Any help with this is appreciated.



Thank you both for the help. When I set the lightmass back to default I get lines around my walls (see second image). I read this was to do with modular walls, so I set my lightmass to the settings suggested in the last image of the page here The lines disappear but I still get the strange artifacts, also more light is bleeding through the corners of walls. I already have blocks behind the walls, with the visibility off to try and rectify this. Any other suggestions?

Thanks Jordon

UPDATE: So the image below has the following world settings:

512 Lightmaps
Static Lighting Level Scale: 0.1
Num Indirect Lighting Bounces: 3
Num Sky Lighting Bounces: 3
Indirect Lighting Quality: 2
Indirect Lighting Smoothness: 0.6
Compress Lightmaps OFF

As you can see the artifacts are still appearing :confused: I assume it’s something to do with the indirect lighting quality? Any suggestions is appreciated.




I just lost my previous post… :S …so once again…

You need Lightmass Portals in your openings (doors/windows)!!
You’ve found the sky multibounce so that’s fine! :wink: …although I would go higher a bit with both bounces…
And I would set Indirect Lighting Quality also higher 4=<… There are people who use the following rule: Static Lighting Level Scale x Indirect Lighting Quality = 1
You’ll see, maybe you’ll need higher lightmap resolution if you’re not satisfied with the result…

You’re almost there!! :slight_smile:
Good luck!

Thanks. I’ve merged the walls, floor, and the ceiling in Unreal. Unreal is laying out the lightmaps like this (see below), is this the correct way of doing things?

Appreciate the help, thanks. This is what it looks like with your suggestions (see below), the weird shadows are fixed. But I’m still getting some light bleed, I have cubes behind the meshes to help stop the bleeding from coming through, these are set to visible OFF, should the visability be set to ON? Also would you suggest making the number of light bounces higher?


Static Lighting Level Scale: 1.0
Num Indirect Lighting Bounces: 25
Num Sky Lighting Bounces: 25
Indirect Lighting Quality: 8
Indirect Lighting Smoothness: 0.75
Compress Lightmaps ON


Really thanks a bunch for the help, as you can see below everything is pretty much fixed now! Plus you helped me learn a bit more about lighting, so thanks!