Texture coordinates, commonly called UVs, describe how to “wrap” a texture around geometry. Lightmaps are textures, so Unity needs UVs to correctly use them in your scene.
|Lightmap UVs introduction||Introductory information about lightmap UVs in the Baked Global Illumination system and the Realtime Global Illumination system.|
|Generating lightmap UVs||How to provide your own lightmap UVs, or have Unity generate them automatically.|
|Visualizing lightmap UVs||How to view the lightmap UVs that Unity is using.|
|Fixing lightmap UV overlap||How to resolve a common issue with lightmap UVs.|