OhMyUnicorn experiment · 22 September 2026 · build 21:09 to 21:24 CET · one model, no pipeline

An AI built this planet in 14 minutes

We gave Claude Opus 5.5 the same one-line brief we gave other models before it. It wrote one self-contained Three.js page on its own, inside Claude Code: no multi-model pipeline, no reviewer, no automatic checks. It took screenshots of its own page three times, fixed what it saw, and stopped.

output a ThreeJS 3D cartoony/comics-like planet, with vibrant life on it: clouds, mountains, city buildings, cars and plane romaing it. It should be possible to orbit around and zoom and see the details. No harness is to be used

Play it

Drag to spin, scroll or pinch to zoom. Close to the ground the camera tilts to the horizon, so zooming in turns into a flyover. Buttons (or keys 1, 2, 3) put you behind a plane or on a car.

Fullscreen ↗

Stills

whole planet — Orbit view: 3 ring roads, 6 cities where they cross, bridges over the sea, puffy clouds, atmosphere rim, comic ink lines + halftone shadows.

close up — Zoomed in: the camera tilts to the horizon. Road over the hills, cars, round and pine trees, snowy peak.

A city by a lagoon, a boat on the water, cloud shadows on the ground.

plane ride — Ride a plane. ⚠ The contrail puffs sit in front of the fuselage in this view (known flaw, not fixed).

car ride — Ride a car: a bus ahead, oncoming car, red bridge rails, sea below.

What is in it

Thing	Count	How
Cars (incl. yellow buses)	78	2 lanes each way on 3 ring roads, head and tail lights
Planes	7	spinning propellers, banking, contrails; one tows a "HELLO PLANET POP!" banner
Boats	9	loop on open water only
City towers / houses	234 / 194	towers get taller at the centre, windows drawn in the shader (some lit); pitched-roof houses on the outskirts
Trees / windmills	2,600 / 12	forest patches from noise; windmills turn on grassy hills
Clouds	52 clusters	two layers drifting in opposite directions, casting shadows
Also		snow caps, beaches, turquoise shallows + foam at the coast, gentle sea swell, a cratered moon, twinkling stars

Comic look = a post pass: black ink lines from depth and normal breaks, halftone dots on the shadow side, a light that always comes from the upper left of the screen so no side of the planet is ever dark. One 48 KB file; three.js 0.170 from jsDelivr.

Cost and time

Measured from this session's own transcript (every API call's usage), priced at Opus 5.5 list rates: $4 / MTok in, $20 out, $0.20 cache read, $8 for 1-hour cache writes.

Window	Wall clock	API calls	Output tok	Cache read tok	Cache write tok	List $
Build (first line of code to last fix)	14.0 min	15	56.6k	2.50M	113k	$2.54

Where the build's $2.54 went: output 45% ($1.13), 1-hour cache writes 36% ($0.91), cache reads 20% ($0.50). Of the 14 minutes, about 7 were waiting on software-GL screenshots (this box has no GPU; each frame takes ~1 s).

Why it costs more than the page's size suggests: the coding agent re-sends its whole working context (~115k to 170k tokens: project instructions, notes, tool list) on every call. The page itself is ~13k output tokens. A bare single API call with no tools and no looks would likely land near $0.5 to 0.8 (estimate, not measured), but would also skip the three look-and-fix rounds that caught the spiky mountains, the milky atmosphere disc and the plane camera staring at empty sky.

Next to the other lanes (same brief, earlier runs)

Earlier runs of the same brief (19 September). This compares cost and time only, not quality.

Earlier test: DeepSeek V4.1 Flash vs Pareto 26.9, same brief ↗

Lane	Time	List $	Notes
Claude Opus 5.5, alone	14.0 min	$2.54	3 look rounds, 48 KB page
GPT-6 Astra, alone (low effort)	4.5 min	$1.23	8 screenshots, 15.8 KB page, gate PASS
Astra plans, DeepSeek writes the page, DeepSeek repairs	14.5 min	$1.55	first page blank, repair PASS
DeepSeek V4.1 Flash, alone (low effort)	14.4 min	$0.31	143 turns, 638 KB page, gate PASS

What this does not show

No real-GPU frame rate measured. Only software-rendered screenshots. Two extra render passes (ink lines) plus a 2048 shadow map; should be fine on a laptop, not measured. Not tested on a phone.
Not fully blind. Before building, the model read our notes on what we liked in an earlier planet (plane quality, two-lane roads, round globe, cloud polish). The other models only saw the brief.
"No pipeline" is not "no tools": this ran inside Claude Code, with a file writer and a headless browser for screenshots.
Known flaws: contrail puffs block the plane in ride view; cars drive through each other where roads cross; roads cut steep trenches through mountains; building windows only read up close; the banner plane's banner is edge-on from behind (ride mode skips that plane).
Needs internet: three.js from jsDelivr, fonts from Google Fonts.

Made by OhMyUnicorn Forge: describe an app in plain words, get a live URL.