worlds via code, from fable 5.1
# fable51-worlds
Worlds as code. A prompt in, a world you can walk out.
[Claude Fable 5.1](https://www.anthropic.com/claude/fable) agent swarms take a brief - a sentence, a photograph, a clip - then research the place, model it, render it, and check it. What ships is a plain [Three.js](https://threejs.org) app that opens in a browser.
No game engine. No proprietary 3D tiles. No downloaded meshes. Every building, storefront, sign, tree and traffic light is generated by code that lives in this repo.
## ⚔️ Head-to-head: Claude Fable 5.1 vs GPT-6 Astra
Both models' entries are one-shot results.
### Union Square, San Francisco
Same brief, same test conditions, two models. Each built Union Square from scratch, then the Astra world was filmed along the Fable walkthrough's camera route and the two are shown side by side, unedited.
▶ [Watch the head-to-head](union-square-sf-gpt-astra/media/fable51-vs-gpt6-astra-union-square.mp4) · 59 s · left GPT-6 Astra, right Claude Fable 5.1 · [Fable 5.1 build](union-square-sf/) · [GPT-6 Astra build](union-square-sf-gpt-astra/)
### Higashiyama, Kyoto
Same brief, two models. Each built Higashiyama from scratch, then the Astra world was filmed to the Fable walkthrough's shot sequence and timing. The two are shown side by side, unedited.
▶ [Watch the Kyoto comparison](kyoto-higashiyama-gpt-astra/media/fable51-vs-gpt6-astra-kyoto.mp4) · 53.9 s · left Codex / GPT-6 Astra, right Claude Fable 5.1 · [Fable build](kyoto-higashiyama/) · [Codex source and viewer](kyoto-higashiyama-gpt-astra/) · [Full Codex walkover GIF](kyoto-higashiyama-gpt-astra/media/kyoto-higashiyama-codex-walkover.gif)
## Worlds
### 🌉 [Union Square, San Francisco](union-square-sf/)
▶ [Watch the walkthrough](union-square-sf/media/union-square-walkthrough.mp4) · 59 s · 1920×1080 · aerial, plaza, Nintendo, lower level, Apple
### ⛩️ [Higashiyama, Kyoto](kyoto-higashiyama/)
▶ [Watch the walkthrough](kyoto-higashiyama/media/kyoto-higashiyama-walkthrough.mp4) · 54 s · 1920×1080 · seven scenes, Gion to Kiyomizu-dera at sunset
More worlds coming.
## Any input → a world
Text, video or image. The brief names the subject and the style, and the same pipeline runs behind all three.
| Input | A brief looks like | The world that comes back |
|---|
| 📝
Text | "Hanamikoji, Kyoto - as a hand-painted anime background" | A named place in a named style: real geometry on surveyed ground, with the look written to order |
| 🎞️
Video | a thirty-second walk-and-talk from a film | The set behind the shot, continued past the edges of frame - step off the camera path and walk the rest of it |
| 🖼️
Image | one photograph, any angle | The place in the frame as geometry: turn around, change the hour, light it differently |
Style is as open as subject. The same street can come back as a cel-shaded anime plate, a photographic reconstruction or a night scene, because each world's renderer is written for it rather than chosen from a list.
## Roadmap
A world is the substrate. What stands on it is the point.
| ✅ | Interactive scenes | Real places, walkable in a browser - this repo |
| 🔜 | Animation and video | Motion as code: shot lists, camera language and continuity held across a sequence minutes long, cut from the world itself rather than generated frame by frame - anime, and documentary camera-matched to the real location |
| 🔜 | Agent environments | Worlds as training and evaluation environments, where the same code that builds the place also supplies the reward and the verification signal - and, played straight, an RPG |
| 🔜 | 4D, embodiment, robotics | Scenes that change over time, and simulation where the ground truth comes free with the geometry |
| 🔜 | Test-time scaling performance | Measure how world quality changes with more inference time and compute |
## How these are made
Every stage is in the repo, and every stage can be re-run:
## Why code