There are multiple goals one can have in mind when making a building generator. Here, I try three different methods that are geared towards 3 different potential goals when making a building.
Building 1: Using a basic construction blueprint you create multiple instances of a mesh, editable in the Unreal editor.
This method is best if you just want to use a few segments of a wall mesh to make a whole building.
The construction blueprint for generating walls.
An interior mapping material has been added to a plane behind the walls to spice up the look of the building, which uses raycasting and a cubemap to create false interiors.
Building 2: This building uses an HDA to generate the building geometry procedurally along a user-defined spline. The user can also input any decor geometry for the windows and doors into the HDA, which are placed randomly for less visual uniformity.
The final product in Unreal engine with materials applied. This method is suited for creating buildings with overall irregular shapes, or for prioritizing being able to add individual window/door/decor assets to certain buildings.
The houdini graph used to generate the building from a spline, allowing for 3 geometry inputs.
Building 3: Unreal materials are applied to 2 cubes to generate all the details of this building, whose floors and damage layout can be easily changed. The inner shell had false interiors and the appearance of damaged cavities from any angle.
The outer shell uses a parallax occlusion material to add false indentations framing each window. The inner cube uses the aforementioned interior mapping material, and a more dramatic parallax occlusion material.
The unreal material generating the hull of the building, using parallax ocllusion for adding fake wall detail to the cube.
The unreal material for the building's interior, lerping between a interior mapping material for the windows and a parallax occlusion material for where the wall appears damaged.