Landscape Mountains: It takes forever to bulid lighthing

HI,
I downloaded Landscape Mountains, and tried to build it, but found that it has been taking forever to build lighting.
Anyone knows what’s wrong? The warning message suggested that the size of the lightmap for the landscape foilage is too large, and suggest reducing it.

Thanks.

Yeah, landscapes are large, generally you don’t want to use baked lighting for large maps because it takes a long time to calculate and takes a lot of disk space.

But dynamic lighting kills performance too.