Strange Lighting Issue With Directional Light Rotation / Sky Atmosphere

Development Rendering
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Hi there! I’ve run into an issue using Lumen in Unreal 5.1.0 and I’ve been slamming my head against my desk trying to figure it out - has anyone run into this issue before at all or be able to hazard a guess as to what causes it?

When I rotate my directional light to be underneath the ground, the light wacks out and makes everything super bright when it should (from what I can tell) be casting no light under the terrain.

It looks like the Sky Atmosphere in my level is contributing to the issue as when I turn it off in the bright area, it fixes itself but obviously the sky has no colour. Any ideas would be appreciated!

Link to the issue in video form here: Unreal Engine 5 Lighting Issue - YouTube

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I have figured this one out!

Taking a look at the base SkyAtmosphere within a new terrain level, the only difference I could find was within the Rayleigh Scattering. After fiddling with the values for a while, it appears that if the value for Red is set to 0, it will cause this issue and if there is any very slight value (currently mine is set to 0.000001) - it will not unnecessarily brighten like it has been. :slight_smile: