Whether to exhaustively check every possible lightmap layout when packing lightmaps.
Enabling this may significantly increase the time taken to calculate lightmap packing, but it helps ensure that the most optimal possible packing will be used. Use with caution.
This setting only has an effect when using LightingSettings.LightmapPackingMethod.XAtlas.
Additional resources: LightingSettings.lightmapPackingMethod, LightingSettings.lightmapPackingMode.