N00b advice on static/stationary lighting behavior in Lumen

Development Rendering
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So I am by any means an expert on these subjects so sorry if asking noob questions I am still learning. I know most of these things can probably be found in the documentation online but it is extensive and quite frankly thanks to me still being new I do not even know where to start in the do cumentation.

So my question is this:
(1) I can not seem to build lighting anymore in my scene. I have enabled Lumen and it seems to be related with that. Some posts mention disabling the option “force no precomputed lightning” but I am not sure I want that based on my assumption that Lumen fundamentally renders scenes differently from the pre-lumen scenes.

(2) I am not sure how Lumen interact with stationary/static/moveable lights. When I make the lights static the preview word becomes visible in the casted shadows/light. Previously I needed to build lighting for that to disapear, but since that option is now gone I am unsure how to proceed. Should I just make all lights stationary?

(3) Another problem seems to be related to viewport clipping or something LOD. When I approach my lights the intensity seems to jump down (decrease) at a certain distance and when I move the camera back the light intensity (for the lack of a better word) seems to jump back up. See my attached image for clarification of this issue. This problem especially seems buggy but I am unsure where to start troubleshooting.

Some information that might be valuable.

  • Engine version 5.6
  • Lumen enabled
    • Dynamic Global Illumination Method = Lumen
    • Reflections Method = Lumen
    • Use Hardware Ray Tracing when available = active
    • Ray lighting Mode = Hit Lighting
  • Ray Traced Shadows enabled
  • Production quality = epic
  • Material quality = epic
  • This is a UE4 project converted to UE5, seems to work almost flawlessly. had no big problems until now.
  • Almost everyting is nanite.
  • Hardware:
    • Nvidia RTX 5070ti
    • AMD Ryzen 7 9800X3D
    • Corsair 32GB DDR5 RAM

Please reply If you could help me troubleshoot / point me in the right direction.

Regards.

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1 Like
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I think your main problem might be a bit of confusion. Lumen is dynamic lighting, that’s the opposite of static lighting. So it’s probably best to use one or the other

1 Lumen and all lights are moveable

2 Turn off Lumen in the project settings, and make all lights static.

I also read that since 5.6, Swarm ( the light builder ) is not in the engine download and has to be added manually. That might explain your problems with light building.

There is also the question of why you would want to use static lighting. There’s a lot online about it, because it was very commonly used in UE4, but since Lumen, you need a very specific use case for static lights. Like for instance, only targeting very low end mobile.