Static Lights Disabled / Turned Off After Building Light

Hello, my question is in response to this:

So, I was working with a scene that had all movable lighting, and that was eating up FPS, so I changed the lighting to static, and after the lighting was built, there was no lighting.

I have another scene (in the link) that demonstrates that static lighting does work with Lumen. So, does anyone have any insight as to what may actually be going on?

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The text you quoted is correct: Lumen does not support static lights. Static lights are exclusive to baked lighting, they store all of their lighting in surface/volumetric lightmaps.

The reason why it “works” until you build the lighting is because Unreal uses real-time lighting to preview static lights so that you can understand what you’re doing before you build it. Essentially they behave like moveable lights. Once you build the lighting, the editor turns the light off and displays the final baked result in the lightmap.

But when Lumen is enabled, lightmaps are disabled, so when you’ve completed your lighting build the lights will just disappear completely.

Then why does the static lighting work in my (personal) scene, even after I built the lighting? Is there a setting I enabled that I need to enable in the other?

Because it’s on medium scalability, where Lumen is disabled and it is falling back to baked lighting.

I’m going to have to push back on you, unfortunately, because Lumen is NOT disabled in my scene. I have the “Lumen Crawl / Noise” and I also have Global Illumination set to high.

You can push back all you like but that doesn’t change the fact that static lighting is unsupported by Lumen. The exact reason why it “works” in your scene, I don’t know. Maybe static lighting is disabled and so after you build nothing happens. Regardless of the reason, these two features are fundamentally incompatible, period. They don’t work together.

Let me check…

There’s a flag in the project settings as well as one in world settings. World partition maps don’t support static lighting, so it will always be forcibly disabled in world partition levels.

Indeed. Checking now.

Also, just for my edification, (and it’s good and appreciated that you’re clearing this up), does the same go for stationary lighting? I mean, does Lumen support stationary lighting or does it only support movable?

Basically yes. Stationary lights are treated as moveable, so although you can use them, they don’t really do anything different.

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You nailed it.

Saved me a few hours.

Thank you!

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