I graduated in 2014 with my project to make procedural buildings using SideFx Houdini. Inspired by games such as Rainbow Six Siege and the Assasin Creed series, I wanted to make a complete building and test the limits of Houdini.
My main focus was to be able to generate the framework of the building based on an chosen architectural style. This style would be made up of different parts, like doors, windows and repeating wall sections. Houdini was used as an editor, putting these parts together.
Once a building is worked out, procedural style rules can be extracted to rebuild these buildings in a game engine from a floor plan or be exported from Houdini as a model (broken up in sections).
With the advent of the Houdini Engine in Unity and Unreal, it became possible to port sections of the node network straight to game.