How to fix blurry dark artifacts on walls?

Hi everyone, I still have some issues with the lighting of my environment.
The main issue is that I have the dark, blurry artifacts on my walls (not the white ceiling corner panels! That’s just UV problems that needs to be fixed).
I already imported the walls, floor and ceiling seperately and have the “Lightmass Resolution” on 1024 (each mesh).
My first and main issue was, in 4.10, as you can see in the corner and the wall:

I read a lot of excisting threads, lighting trouble shooting, and the “Lets make Lightmass EPIC (and understandable)” thread.
I Also tried and test out a lot of “Lightmass Setting” from several treads but didn’t really worked out, incl. the “Lightmass Portals” in 4.11.

Then I upgraded my 4.10 project to 4.11, I noticed my scene was a lot darker and was not the same as before (first picture).
So I removed the “Saved” and “Intermediate” folders and rebuild the light again.
Then I change the “Lightmass Setting” until it was the closest I could get back as the first picture + without the artifacts.
That look as follow in 4.11:

My question is, how can I get rid of the artifacts and get the sharpness back of the first picture in my current scene (second picture, 4.11)? (Without that the artifact get more worse on the wall).
If I try to scale down the “Static Lighting Level Scale” below 1, the artifacts starts to get worse and worse. Even if I try to smooth it with the “Lighting Smoothness”.
What I did notice is if I increase the “Directional Light - Intensity”, the artifacts also get more worse.

Another question is, should I choose to go back and continue in 4.10, or 4.11?
Since my scene looks better and sharper in 4.10 but I can’t get rid of the artifacts in 4.10 and aswell as 4.11.
Maybe someone can give me good advice?

Small notes:

**- I build on “Lighting Quality - Medium”.

  • I DIDN’T change anything in the .ini files!
  • As you can see in the pictures, I use for lighting: “Directional Light” and “Sky Light”.
  • I already imported the walls, floor and ceiling seperately and have the “Lightmass Resolution” on 1024 each mesh. I also tried 256 and 512 on each mesh.
  • The UV’s are good and the UV Channels 0 and 1 also look fine of each mesh (wall).**

An example of one of the testing results in 4.11:
Static Lighting Level Scale: 0.4
Lighting Smoothness: 0.8
Directional Light Intensity: 8 (I changed it from 6 to 8 based on the current scene).

Looking at the shadow on the floor it looks like low lightmap resolution. Could you please double check those meshes and see if they dont have their lightmap resolution somehow overridden to a lower value inside the level > details panel? If they are correct set Static Lighting Level Scale back to 1 and increase Indirect Lighting Quality instead(start with 2) Then build at Production quality and see how it goes.

Hi Jacky, thanks for you respond and answer! I will double check and try to set the Static Lighting Level Scale back to 1 and increase the Indirect Lighting Quality + try to build at Production Quality. I will let you know if it works out :slight_smile:

Hi Jacky, sorry for the late respond! I took a while to render on a high settings :).
First I was looking back what you’ve said and my Static Lighting Level Scale was already on 1 and Indirect Lighting Quality was already on 10. So that wasn’t the problem.

The problem was that I my lightmaps were leaking. I did manage to solve the problem by:

  1. Made own Lightmaps in Blender.
  2. Import into UE and tick-off auto gen. lightmap uv.
  3. Lightmass resolution 1024.

And everything was solved :slight_smile:
(Please ignore the black box and etc, I just turned it off for rendering but it was still casting shadow haha)

Thanks a lot again for you respond!

Ah, ok. When you said it looked fine in 4.10 i ignored broken lightmap UV possibility. Glad that you figured it out though!