Was trying various projects with Unity to understand the engine back in 2016, so the procedural generation project was put on hold until late 2017. The version on December 4th, 2017 shown below was composed of stacked generated cubes of various materials, with a random placed object from a set of Gameobjects placed on top.
This was obviously non-performant, but my goal back then was to identify the rules I needed to establish to make a generated city believable. This version was to test if I could generate various window patterns on the wall surfaces and have the code randomly place objects as needed. There were observable issues – e.g. middle bottom building has windows that occur in one corner and not the other – but seeing issues like that meant I can figure out new rules to fix them.