Sixty-five visualizers, six renders each, one per song — each carrying that
song's whole identity: its cast, ink, lattice, palette and a fresh parameter
draw. Side by side, a scene that cannot be changed by the song is obvious in a
way no aggregate could show, which is the complaint this answers.
It scores as well as shows. Each row carries the mean structural distance
between its own six frames, on the same descriptor the variety harness uses and
with colour excluded, so six palettes cannot disguise one image. Sorted
least-varied first, because browsing sixty-five scenes hunting for the
repetitive ones is precisely what a sort order should do for you.
The result names names. Thirteen scenes barely change across six songs, and they
fall into two groups that were already known separately. The ink-only
migrations — Analog Wow, Halftone Misprint, Pitch Shatter, Block Mosh, Scan
Tear — are the shallow tier flagged in MIGRATION.md, where the whole migration
was one posterisation. And Moiré Grid, Isometric Blocks, Quasicrystal, Truchet
Fold, Voronoi Shatter and Apollonian Gasket are the structural twin cliques the
library sweep found weeks of measurement ago, arriving here by a completely
different route: the sweep compared scenes to each other, the gallery compares a
scene to itself, and they agree on the same offenders.
debug.html collects the tools, since there are now enough of them that knowing
which to open is its own problem. It also carries the two things a newcomer
would otherwise learn the hard way: which measurements are safe to steer by
(direct render comparisons) and which are not (aggregate ratios), and what to do
when a page renders perfectly and does nothing.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Engine core: Timeline (fixed dt, audio-mastered in realtime), seeded Rng,
Renderer, Layer/ShaderLayer/SceneLayer, Compositor with blend modes,
feedback and post chain.
Shader scenes are compiled against a fixed uniform contract and define only
`vec4 scene(vec2 uv, vec2 p)`, so adding a scene costs a shader plus a
params block. Deep Nebula ported from party-stage as the first one.
Gate passes, 7/7 in checks.html:
- 300 frames rendered twice are bit-identical
- a fresh Engine reproduces the same frames
- simulated dropped frames change nothing (proves dt is fixed)
- seek matches sequential playback
- 320x180 vs 1280x720 agree within 0.010 (limit 0.06)
- seeded rng reproducible, forked streams independent
- compositor reset clears feedback history
Static gates: no wall-clock or unseeded randomness in deterministic
directories; scene schemas and shader sources agree in both directions.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
