Dirty Shadows

Hi everyone,

i have a quite strange problem. I’m creating an interior/exterior scene and I have some shadow problems. I found many ways to fix them and in the beginning it worked very fine. So first here are my lighting settings:

Scene has:
Directional Light (stationary)
Sky Light (stationary)

World Settings:

Static Lighting Level Scale : 0.2
Indirect Light Bouces: 30
Indirect Lighting Quality 10
Indirect Light Smoothness 0.75

With this settings i’m able to have a very good look in my “light-lab level” where I can test the settings (no dirt, very smooth, even in very dark areas). Now I moved to my main scene with the same settings, same meshs and light map resolutions! (512 or sometimes 1024). And it get this:

Whats going on there? Is it possible that a bigger and larger scene needs a different light setting? Do you have an idea?


this page contains all information you need about lighting troubles

Well i checked this site befor. And as you can see i’m using Even better Lightningsettings as in this article. So thats the reason why i can’t understand where these problems come from…

Well okay … here are two pictures. As i said: both levels have the SAME Settings in World and the same lights in level.
The geometry for this room is also the same with the same Light Map Resolution. But as you can see there is a huge difference… Its not only this one wall. Many Objects have this Problem in my main scene. Once again here are my settings:

  • Static Lighting Level Scale : 0.2
    Indirect Light Bouces: 30 Indirect
    Lighting Quality 10 Indirect Light
    Smoothness 0.75

Light Test Scene : Everything is fine:

Main Scene: Dirty Shadows:


you need to change these things

Indirect Lighting Quality

Indirect Lighting Smoothness

Num Indirect Lighting Bounces

All in world setting

change the light map resolution of that wall with bad shadows

open wall mesh and under static mesh settings you will see light map resolution of that wall

use a lightmassimportance volume

it is really cool .

every little object in your scene have their own lightmap settings take a look at them one by one. something maybe broken.

it is as if you have used different materials for those chairs :smiley:

Well i had a closer look at my objects and i didn’t override the Lightmap Resolution in the Level Editor. The Chair (in both Scenes) has a Resolution of 1024… And yes of course I’m using an importance volume…

And the material is nearly the same. only roughness is set to 0.9 in the Main Scene. But also walls like in the first picture with the same material having this problem :-(… Or is there a internal Crash for this Level, so Lightbuilding in this quality isn’t possible?

I already experienced this lighting problem but lighting trouble shooting guide solved my problem.

the only other thing that I can say is use a higher quality build. it is set to preview by default

I’m using the high Quality Setting. I will reset all my lights and will Build the Level on monday. I saw That i have 570 unbuild objects, if ichange the Lightning. Are ~ 600 objects too much ?