Mapping is the same technique for all objects.

Yeah, mapping was a really torture, but I accepted it at the beginning of this project.

First I must divided the main building into three parts, and textured them separately. The middle parts have incredible poly count, and I had alot of problems with unwrapping and moving the vertices in edit dialog, in the Unwrap modifier. Next I divided the objects into ID's and after that, I used the UVW map and mapped all ID's with only a standard planar mapping. After that I used the Unwrap modifier, for final mapping process.

First I adjusted all the ID's and then moved and relax vertices and welded the ID's together as I went. I then saved the UVW as a bitmap (you can use Texporter or something similar), I used saving through Unwrap (when is functional).

For correct mapping use checker map!

Here are some examples. You can see some stretched parts, which I repaired with the relax dialog in unwrap.

For all the objects I used, Maxwell diffuse material with the texture in the diffuse slot and bump map all except for the leaves. For the leaves I used a plastic material with the roughness and bump, for the water drops I used dielectric material.