Hello, I just started using lumen recently, but I found this light artifact everytime I setup skylight, I add directional light , ppv , and sphere with hdr and everytime I switch to lumen from static light I get this white artifact which is somehow screenspaced so it’s always follow the camera in the center.
I’m sorry in advance if I’m having a setup blunder but I remember testing same setup few months ago and I didn’t recall having this issue but I didn’t endup using lumen much since initial test so please forgive me if I made some mistake in my setup, thanks
I’m basicly trying to remove the clouds , the SkyAtmosphere and switch the Skylight to capture scene from the hdri sphere but I get this artifact, when I use the SkyAtmosphere and realtime capture I get no artifact
While I don’t know exactly how you’re using them, my understanding is that HDRI spheres are not a supported feature by lumen, and that you’re going to need to use the skylight alone if you want artifact-free rendering.
how’s the hdri sphere done? you may have to find this switch in the material named “is sky”. that shold prevent it from casting any shadows or mess with the directional lighting or sky light.
This was it! , I only switched off shadows on the sphere and totally forgot to enable issky , I realized it had something to do with my setup since everything worked fine when I used the hdribackdrop , thanks alot!
I think I got excited too soon, after looking closer the artifact was still there after fixing issky , but wasn’t clear from directional light intensity.
I made same setup twice again once with hdribackdrop and once with editorsphere and sky material but there is always artifact with the sphere.
It also happens when I use capture scene skylight , did you try to use hdribackdrop? that seems to work fine , the problem must be in the sphere or sphere material but I don’t know why , I’m using the editor sphere
Just like lumen has issues with small emissive objects, ensure your cubemaps also do not have small bright pixels. I had left my sun enabled in my sky material, which created a very intense bright spot in my captured cubemap.
Capturing the cubemap without the sun resolved my issue.
Revitalizing this thread because I am running into the same problem. This seems to be a limitation of lumen? I managed to really bring it out by using only a sky light with a cube texture and killing all other light and then dimming the lighting a lot.
In general its a bigger cube around the camera and then a smaller circle if you’re close to other actors.
I’ve played around with a lot of cvars and settings. Here are a couple points:
Is purely a skylight thing with any type (realtime capture, scene capture and cube texture)
Only happens with Lumen GI
Is not affected by other light types.
Is ALWAYS there, just not very noticable in most lighting scenarios or scenes, especially if you use a brighter directional light. But a dimmly lit scene that is relatively flat makes it very apparent.
No matter if normal level or world partition.
Lumen Settings in Post-Process don’t affect it at all.
Lumen Reflections don’t do anything to it.
I couldn’t find any cvars that expand it or at least affect it at all.
Oddly has Lumen Flicker close to camera and far away, but not inbetween.
Tested in 5.3.2 and 5.4.4, no difference.
So yeah. Since I haven’t found a workaround, any tips would be greatly appreciated.
