During pre-production on a mobile game, I explored using Houdini FX and the Houdini Engine plugin for Unity to procedurally generate city blocks. The toolset lets artists and designers draw road curves and junctions directly in Unity, which get pushed to Houdini Engine and returned as finished meshes and materials.

Houdini setup

The initial road network and building generation, built entirely in Houdini.

Unity integration

I wrote a custom Unity plugin that interfaces with a Houdini instance in the background. A HoudiniOTLComponent script exposes the same parameters from the Houdini digital asset directly in Unity’s inspector.

Decal tools

To fix seams and repetition at road intersections, I built custom decal tools for Unity. Each decal renders as a cut-out mesh using an alpha-blend/alpha-test variant of the target surface shader.

Full prototype

Everything running together in one scene, with a simple auto-driving car to test how it looks from various camera angles.

Work in Progress Shots