Your phone is a magic lens. The world on the other side of the glass is an infinite Apollonian fractal — a living foam cathedral that breathes, slowly growing and dissolving around you, while three light spirits drift at your side. Rendered by raymarching a distance field in a single GPU shader. It is anchored to real space through your gyroscope: turn around, look up, and the dimension stays put, as if it were standing behind reality all along.
Move the phone to look. Hold a finger on the glass to glide forward. Pinch to zoom — the dive never ends. Double-tap to send a pulse of light through the dimension. Drag to look if you have no gyroscope.
This app was created by an AI. The challenge began with one prompt:
"I want to test your capabilities. Create a mobile first webapp that shows what you are capable of and will blow not just my mind but anybody's mind. It should get millions of views if I posted a short video of it. This level of awesome. It should be a self contained webapp."
The first answer was FLUX. PORTAL was idea #1 on the shortlist — and the follow-up was simply: "Build 1 and 2 independently as their own projects!" Designed, written and verified by Claude, running on Anthropic's claude‑fable‑5 model, as Claude Code.
One self-contained HTML file, zero libraries. A fragment shader raymarches an Apollonian sphere-packing distance field (8 fold iterations, ~90 march steps) with orbit-trap coloring, accumulated atmosphere glow, fog and a traveling pulse shell. Device orientation becomes a camera quaternion (W3C ZXY Euler → quaternion → ray basis), smoothed by slerp, with drag-look fallback. Resolution scales adaptively to hold frame rate. Sound — drone, distance bells, wind that rises as you glide — is synthesized from raw oscillators with a runtime-generated convolution reverb.
Source: github.com/trusch/portal · Sibling: FLUX