I followed this tutorial by Jerome Etienne on generating a procedural city using Three.js.
The tutorial was a way to learn more about Three.js. Most of my time was spent figuring out how to update methods used in the tutorial (r59) that are deprecated in newer versions of Three.js (I was using r73).
Some pictures from debugging
Removing texture from roof - before
Fun times with the roof texture location when attempting to merge buildings
Testing that both vertexColor and base color work