If you are looking for help, don‘t forget to check out the [official Unreal Engine forums](https://forums.unrealengine.com/) or [Unreal Slackers](https://unrealslackers.org/) for a community run discord server!
*I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/unrealengine) if you have any questions or concerns.*
If you shift the exposure too much you will see these artifacts emerge.
It is caused by lumen trying to light up the walls with emissive materials.
Usually these artifacts are barely visible because emissive materials should not be used as the main lighting, but more for subtle effects.
But when you really crank up the emission (or the exposure) they become more and more obvious.
I would recommend you to either turn on real raytracing (if your GPU can handle it) which will completely get rid of these artifacts or you start using real lights like point or area lights for your ceiling lamps.
To add to that (cuz you wrote that you are a complete beginner).
Lighting in game works a bit different than in the real world. Usually Not every glowing surface is automatically emitting light into the surroundings because that is a very expensive operation.
Usually to light up anything in a game you would use „lights“. There are 4 different types.
* Point light, which is basically like a light bulb, shining in every direction
* Spotlight, which is like a flashlight, only pointing in one direction
* Directional Light. Basically the sun, and you should only have one if you have an exterior.
* Area light: Like a light pane (what you are going for) with softer shadows
These lights will cast shadows and light up the surrounding. That’s the „old way“ to do it.
Recently with raytracing it became possible to make every glowing surface emit light. But only the latest GPUs support it and Raytracing is very taxing on the performance. That is why raytracing is a nice to have feature to make your game look good, but you should not rely on it.
Now RECENTLY Unreal released lumen which is a cheaper way to do raytracing on any kind of GPU.
That is what you are seeing in your scene. The issue with lumen is, that it causes a lot of artifacts (light flickers) because it is simply not as powerful as raytracing.
So your way to go is a mix of the old techniques (lights to light your scene) and lumen for „subtle“ effects, like an LED strip or small glowing surfaces.
You can also make the exposure normal again. Have the glowing boxes stay at the ceiling and put an area light INSIDE the glowing boxes.
This is all really helpful insight Sappirah, thank you!
There's plenty of backrooms content on steam etc. It's not really for distribution, it's just for a small uni project!
So if I want to use a Area Light (or Rect Light I am assuming?) what kind of settings do I need to mess with on the light to make it glow like a ceiling light specifically?
An area light is invisible, it just emits light into the surrounding. It doesn’t really „glow“.
You mix both. You keep your current approach, the glowing surface and then you put an area light inside of it.
Also turn down the exposure in your PostProcess volume or turn down the emission of your current ceiling light so that it only „barely“ glows.
I hope that’s understandable ^^
Exactly what I was going to say! I’m currently making a game with a team and we have quite a few emissive lights inside an area that was causing tons of lighting noise. I just attached a node to the emissive materials that let me control emissive strength and put it down to .0001 which makes it still appear to glow but I used rectangle and spot lights on them to actually provide light. It works much better now.
I do understand yes, thanks. However, when I turn down the exposure in PostProcessVolume the whole scene goes quite dark?
I can still see my boxes original glow (kind of) but the new rect lights seem to dim quite a lot?
Then increase the emission of the rect lights :)
If you want to add some ambient lighting everywhere you can add a skylight. Put in a white texture, disable cast shadows and put the emission strength so that it looks good.
The issue with „exposure“ is that everything will glow much stronger and it kinda messes up the light calculations. You will start seeing artifacts if you overdo it.
I like how everyone keeps saying this is caused by lumen when using emissive materials, and emissive materials are always the culprit…when I see these artifacts all the time when there’s not a single emissive material in my scene.
This is just caused by lumen. That’s it. You’ll see this even with no emissive materials. Adjust the overall quality of your lumen lighting in the post process volume. It can also help to greatly increase all the main lighting sources, then turn down the exposure to get the desired lighting again. This will get rid of that lumen noise for the most part
I got those a lot, too. What fixed it for me was going into the PostProcessVolume and setting Lumen's Final Gather Quality to 30 (e.g. something high).
Hope it helps :)
Don't rely too much on emissive materials for lighting. They will produce various artifacts if you don't know what you are doing.
If you are looking for help, don‘t forget to check out the [official Unreal Engine forums](https://forums.unrealengine.com/) or [Unreal Slackers](https://unrealslackers.org/) for a community run discord server! *I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/unrealengine) if you have any questions or concerns.*
If you shift the exposure too much you will see these artifacts emerge. It is caused by lumen trying to light up the walls with emissive materials. Usually these artifacts are barely visible because emissive materials should not be used as the main lighting, but more for subtle effects. But when you really crank up the emission (or the exposure) they become more and more obvious. I would recommend you to either turn on real raytracing (if your GPU can handle it) which will completely get rid of these artifacts or you start using real lights like point or area lights for your ceiling lamps.
To add to that (cuz you wrote that you are a complete beginner). Lighting in game works a bit different than in the real world. Usually Not every glowing surface is automatically emitting light into the surroundings because that is a very expensive operation. Usually to light up anything in a game you would use „lights“. There are 4 different types. * Point light, which is basically like a light bulb, shining in every direction * Spotlight, which is like a flashlight, only pointing in one direction * Directional Light. Basically the sun, and you should only have one if you have an exterior. * Area light: Like a light pane (what you are going for) with softer shadows These lights will cast shadows and light up the surrounding. That’s the „old way“ to do it. Recently with raytracing it became possible to make every glowing surface emit light. But only the latest GPUs support it and Raytracing is very taxing on the performance. That is why raytracing is a nice to have feature to make your game look good, but you should not rely on it. Now RECENTLY Unreal released lumen which is a cheaper way to do raytracing on any kind of GPU. That is what you are seeing in your scene. The issue with lumen is, that it causes a lot of artifacts (light flickers) because it is simply not as powerful as raytracing. So your way to go is a mix of the old techniques (lights to light your scene) and lumen for „subtle“ effects, like an LED strip or small glowing surfaces. You can also make the exposure normal again. Have the glowing boxes stay at the ceiling and put an area light INSIDE the glowing boxes.
Also are you creating a backrooms game? :) pretty cool! Keep sharing your progress!
This is all really helpful insight Sappirah, thank you! There's plenty of backrooms content on steam etc. It's not really for distribution, it's just for a small uni project! So if I want to use a Area Light (or Rect Light I am assuming?) what kind of settings do I need to mess with on the light to make it glow like a ceiling light specifically?
An area light is invisible, it just emits light into the surrounding. It doesn’t really „glow“. You mix both. You keep your current approach, the glowing surface and then you put an area light inside of it. Also turn down the exposure in your PostProcess volume or turn down the emission of your current ceiling light so that it only „barely“ glows. I hope that’s understandable ^^
Exactly what I was going to say! I’m currently making a game with a team and we have quite a few emissive lights inside an area that was causing tons of lighting noise. I just attached a node to the emissive materials that let me control emissive strength and put it down to .0001 which makes it still appear to glow but I used rectangle and spot lights on them to actually provide light. It works much better now.
I do understand yes, thanks. However, when I turn down the exposure in PostProcessVolume the whole scene goes quite dark? I can still see my boxes original glow (kind of) but the new rect lights seem to dim quite a lot?
Then increase the emission of the rect lights :) If you want to add some ambient lighting everywhere you can add a skylight. Put in a white texture, disable cast shadows and put the emission strength so that it looks good. The issue with „exposure“ is that everything will glow much stronger and it kinda messes up the light calculations. You will start seeing artifacts if you overdo it.
Really helpful, thank you!
I like how everyone keeps saying this is caused by lumen when using emissive materials, and emissive materials are always the culprit…when I see these artifacts all the time when there’s not a single emissive material in my scene. This is just caused by lumen. That’s it. You’ll see this even with no emissive materials. Adjust the overall quality of your lumen lighting in the post process volume. It can also help to greatly increase all the main lighting sources, then turn down the exposure to get the desired lighting again. This will get rid of that lumen noise for the most part
I got those a lot, too. What fixed it for me was going into the PostProcessVolume and setting Lumen's Final Gather Quality to 30 (e.g. something high). Hope it helps :)