How to texture a huge city? I followed a tutorial to create a city using .osm map file, and ended up with a red-colored city, (with red buildings), I wanted to know how do I texture it?
Tutorial I followed

In the tutorial, he states something about a texture atlas, which I couldnt understand. 
Thanks!
Around 2:00 minutes at the step 4 of the video tutorial : compose the texture atlas.
This texture is simply a single large image composed of several buildings facades and roofs images found on CGTextures.com.
So this is simply a copy/paste process.