I haven't looked at the code of this demo but it seems there's no dynamic lighting at all, the "lighting" of the face of each cube depends only on which side it

I haven't looked at the code of this demo but it seems there's no dynamic lighting at all, the "lighting" of the face of each cube depends only on which side it's facing as far as I can tell. You can see that the underside of trees is pretty luminous for instance.