I understood my mistake. I’m accustomed to paradigm of old game engines, such as Irrlicht, Quake 3, etc. with a light map that replaces lighting.
There’s another logic here. There is BaseTexture, MetallicRoughnessTexture and OcclusionTexture. And each of them can have its own UV coordinates, as I understand it. OcclusionTexture can be used as an analog of a light map and, moreover. And it can
be combines with light sources. This method can allow make pretty good looking shadows in static scenes.
There is my test scene for researching this shadowing method:
lightmap_test.zip (2.0 MB)