Dark zones in the room. (Lighting)

Hi all;

I have a little problem about ilumination with my project. I have some meshes of my room hidden by a curtain. This curtain has a Subsurface material and I like the effect that it simulates, but it get dark a small part of the room and I don’t know how to fix it.

The steps that I followed:

  • Locate meshes and textures.
  • Locate Directional Light, Lightmass Importance Volume and Post Process Volume. Also I located two spot light near of the windows and a Skylight with an intensity value of 3.
  • Modify max and min brightness of the Auto Exposure to 0.1 and the Exposure Bias to -2.

This are the results that I get when I build the lighting. I get a lot of places dark.


I tried to change the curtain material to a translucent material with a 0.99 opacity value and I get fix it a little but… I don’t like the results.


I also tried to delete the curtain mesh to test if the curtain is the truly problem and no another thing.


The thing is that I would like to get a global ilumination of the room without to put lamps mesh or lights into the room.

Could someone give me any advice, please?


So what are your world lightmass settings?

What happens when you set the skylight to moveable? :slight_smile:

Also, you need to increase your lightmap resolution on some of the meshes.


I have the default values from when I created the level. I found this link and I am going to try to change some parameters like Num Indirect Lighting Bounces and Diffuse Bosst. I will come back with the results.


Well, I tried that. It is working relatively well. However, my dear shadows dissapeared. The first image looks more contrasted due to the lighting, although there are a lot of strong dark shadows. In this case, the room looks better illuminated, but I miss the contrast that I was looking for to my scene. I tried to change the intensity of the Skylight and the Bias of the Post process and I get some contrast, but very low.

I have changed the lightmap resolution to 512 for the walls and 256 for the rest of the furnitures. I realized that this change added more time for my lighting build time. Should I raise the value even more?

If you look at the yellow wall on the right in your last image, it doesn’t look very well defined, it’s kind of an odd shape, along with the shadows behind the paintings on the left, and the shadows on the floor. That’s due to the lightmap resolution.

Increase number of light bounces to 10 or 100 (computation impact is minimal). Also in your main light (the sun) increase the indirect lighting scale. Double it or so.

Also if you want to better debug the lightmaps, turn on lightmap viewmode in the viewport settings. That way you can see how much space one actual lightmap texel takes on the walls.

Hi all again!

First I want to thank you for your help! I made some tweaks in my level:

  • I placed some spotlights in the ceiling. The intensity value is very low by it is enough for recover some dark zones.

  • I changed my world settings values to the recomended by jonimake.

  • I made some tweaks in my post process volume and I also added a Color Grading.

  • I remade some Lightmaps uvs for some of the walls. The walls of the room have a 1024 lightmap resolution in this moment.

Well, these are the results:

UE4Editor 2015-08-20 18-42-46-455.jpg
UE4Editor 2015-08-20 18-43-04-862.jpg
UE4Editor 2015-08-20 18-43-23-720.jpg
UE4Editor 2015-08-20 18-43-49-160.jpg

What do you think about it?

I found a odd lighting just behind of the left pilar where are the crystals. If you look the picture, the lighting of the floor looks like don’t find any pilar to make shadows and get dark that place. My sunlight and spotlights of the windows point to the same location (the bed), I mean, they have the same Z rotation. So, shouldn’t the pilar make a little of shadows in that place?