Color Banding problems with Lightmass (UE 4.7)

I have huge problems with color banding in my project. The walls of my room have these artefacts after baking the light. This looks really terrible. I have increased the light map size, disabled texture streaming and so on. But nothing helps. The lightmass settings should also be ok. What can I do to solve this problem?

Best regards, Andreas

Is that a BSP or a static mesh? Are your lights set to static, stationary, or mobile?

I am using a static mesh. The lights are stationary.

Hey Andreas -

Please have a look at our Lighting Troublshooting Guide, found here specifically the section called, Why is there shadow splotches on my static mesh?, or How to clean those dirty lightmaps?

Thank You

Eric Ketchum