I ran into a special problem. Our scene setup is using the Ultra Dynamic Sky plugin. For reducing flickering in our scene, I used the cvar r.TSR.ShadingRejection.Flickering.Period=10 to reduce flickering. Unfortunately when changing the light time, you can visibly see that there are “light artefacts”. And the scene needs more time to settle until it is gone.
Do you have any idea what is causing this? I will try to see if I can reproduce it with an Unreal light source as UDS is quite a special thing.
Edit: This is caused by using a noise node for creating a normal map. Using a static noise solves this. The effect is very obvious in the shadow and if you apply this noise directly you can see that it is only noisy and living in the shadows.
Edit2: issue was actually mipmap gen settings of the normal texture set to “NoMipMap”. Choose any other value here to get rid of the error.