Light Management Questions in UE5 with Lumen: emissive material Light Issues

[toyre]

I have a couple of questions about light management in UE5 with Lumen. In the scene from the video, I’ve added two neon lamps with emissive colored materials. I’d like to understand why when the camera isn’t directly focused on the two lamps, the emitted light disappears, and how I can fix the flickering of light in the environment.

Thanks

[ZacD]

Lumen can fall back to screen space only if a scene isn’t setup well for lumen

Make sure lights have mesh distance fields enabled, check the lumen debug views under lit, you can check emissive light source on static meshes used for lights to make sure they get culled later. Emissive lights also aren’t a replacement for light actors with lumen, small bright emissive are inherently unstable, they generally should be weak or large to avoid the limitations of Lumen.

[toyre]

thanks for the clarification. Emissive lights cannot entirely replace regular lights.

(However, make sure to select “Emissive Light Source” within the emissive light source mesh to prevent them from disappearing when not directly in view.)