Lightmaps give me large and dark squares on mesh

this problem is driving me crazy…
I have a custom mesh used as part of a landscape: I did both the UV channel 0 and 1.
When building the lightmaps I get this awful result:
I basically have correct shadows (for example,look at the rocks) but ALSO that strange dark squares.
Please note that they aren’t related to the topolgy of the mesh that is completely different.
I have a lot of lights in my scene, points, spot,and a directional… Maybe one (or more) of them causes this thing but I can’t really find the guilty.
any help is most welcome :slight_smile:


Is the ground made up of multiple squares? If so then that’s why

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