Weird shadow after built the lightmap

[brahoule]

After building the light I get this weird waving shadow effect. Anyone know what is going on?

[brahoule]

@wickerman123

A low resolution lightmap will create artefacts like that due to interpolation - which is define by the “lightmap smoothness” value in world settings.

Make sure your lightmap resolution is high enough for what you need.

I don’t have this setting in 4.18.3… here is a picture of my settings;