Dev builds infinite procedurally generated city world with Claude Code
A developer gave Claude Code an ambitious challenge: build an infinite, voxel world with full city life, including explorable building interiors, NPCs with daily routines, mass transit, local transport, and a day/night cycle. The project took about two weeks to build.
NPCs get up, go to work, meet friends, have dinner, and go home. Trains connect different cities, while buses and subways handle transport within a city.
The world generation uses an integer-only nested algorithm: it lays out large-scale terrain loosely first, then generates progressively finer layers down to individual objects inside buildings. This post mainly showcases a video of the result; a follow-up will cover how Claude was guided to handle a project this large without losing track of details.
Key points
- Built an infinite voxel world with Claude Code in about two weeks
- NPCs follow daily routines — waking up, working, socializing, going home
- Includes mass transit between cities and local buses/subways within cities
- Uses an integer-only nested algorithm, generating from coarse terrain down to individual objects
- How to keep Claude consistent on such a large project will be explained in a follow-up post