89e05459c0
A section used to be one scene, and two thirds of the library is composable —
sparse by design, elements ON something. Cast as backgrounds anyway, they left
9 of 40 sampled frames under 20% painted, the darkest at 0.3%: a minute and a
half of a few bright things on black, invisible to every gate because every
gate on the stack was a limit rather than a floor.
Every section now stands on a GROUND: a canvas that fills the frame, cast per
section kind so a shot cut changes the shot and not the world. When the shot
fills the frame itself it IS the ground — two canvases stacked is two pictures
fighting. Above that, a coverage BUDGET: director appetite times the section's
energy times where the story is, capped at two frames' worth of material.
The measured facts move into the repo. scenes/metadata.json is generated from
the gallery — coverage as a shot, coverage as a bed, variety, the structural
profile — tracked in git, stamped with a fingerprint of the scenes and the
metric definitions, and refreshed from gallery.html. `surface` is derived from
it rather than declared; nine scenes claimed `canvas` while painting under a
third of the frame, and declaring it is now a lint error. The generator weights
every layering choice by measured structural distance, because family labels
and the render disagree: two `geometric` scenes can be 0.31 apart and a `flow`
and an `organic` scene 0.04.
The gallery's 0.1 red line is gone. It was right when a section was one scene
and wrong now — nineteen scenes were failing a bar for being consistent, which
is a virtue in an ingredient.
Chasing the numbers turned up four real faults:
* A scene that reads prev() cannot be a ground. It returns the whole
composited frame including the layers above it, so a datamosh under a shot
is eating it: the render stopped reproducing from a seek and two WebGL
contexts diverged by 91/255 against a tolerance of 4.
* Screen was the wrong operator for a shot over a bed. It lightens, so a
median quarter of every frame clipped to paper and whole sections rendered
100% white. Replaced by a lumakey — the shot's brightness is its alpha.
* Feedback was an accumulator: a still image settled at 2.3x its own
brightness. Fine over black, fatal over a filled ground. Normalised at 0.6,
plus a highlight shoulder so the top rolls off instead of clipping.
* useTrack never prewarmed, so a fresh Show's first frame differed from every
later render of it — the export-breaking hazard Compositor.prime documents.
Blazing is a decision now, not a side effect: directors declare an appetite for
it, a section must be loud and late in the story to earn one, and quiet kinds
never do. The ceiling gate matches that — a hard cap per section, and no more
than a fifth of them hot at all.
Rendered across twelve videos, middle of every section:
painted 51% mean, darkest 0.3% -> 87% mean, darkest 43%
clipped white 24% median, worst 100% -> 1% mean, worst 30%
separation 0.10 -> 0.44
Seven scenes can ground a section — five geometric, two organic — so every
quiet section of every video stands on one of two beds. That is the library's
largest hole and it is scene work: there is no minimal or flow canvas that
fills half the frame without reading prev().
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
80 lines
3.1 KiB
JavaScript
80 lines
3.1 KiB
JavaScript
// Flow family: spiral arms winding into a slowly wandering core.
|
|
//
|
|
// Differential rotation is the point — the inner arms turn faster than the outer
|
|
// ones, so the arms wind up over time and the image is never twice the same.
|
|
// Distinct from Curl Flow (isotropic advection with no centre) and Kaleido
|
|
// Tunnel (rigid radial symmetry receding): this has one centre, real shear, and
|
|
// no symmetry at all.
|
|
//
|
|
// The core is drawn in the track's signature form, so the eye of a hexagonal
|
|
// track's vortex is a hexagon.
|
|
|
|
export const vortexDrift = {
|
|
name: 'Vortex Drift',
|
|
family: 'flow',
|
|
kind: 'fragment',
|
|
consumes: ['cast', 'ink'],
|
|
traits: ['shape', 'camera', 'style'],
|
|
|
|
params: {
|
|
arms: { type: 'int', range: [1, 7], default: 3, uniform: 'u_arms', bias: 'density' },
|
|
winding: { type: 'float', range: [0.5, 7], default: 2.5, uniform: 'u_winding', bias: 'density' },
|
|
shear: { type: 'float', range: [0.1, 2.5], default: 1.0, uniform: 'u_shear' },
|
|
speed: { type: 'float', range: [0.02, 0.6], default: 0.15, uniform: 'u_speed', bias: 'motion', rate: true },
|
|
turbulence:{ type: 'float', range: [0, 1.2], default: 0.4, uniform: 'u_turbulence' },
|
|
core: { type: 'float', range: [0.0, 0.4], default: 0.12, uniform: 'u_core', bias: 'energy' },
|
|
falloff: { type: 'float', range: [0.2, 2.0], default: 0.8, uniform: 'u_falloff' },
|
|
palette: { type: 'palette', count: 5 },
|
|
},
|
|
|
|
reactive: {
|
|
core: { feature: 'beat', amount: 0.3, response: 'spike' },
|
|
turbulence: { feature: 'bandMid', amount: 0.3, response: 'smooth' },
|
|
},
|
|
|
|
shader: `
|
|
vec4 scene(vec2 uv, vec2 p) {
|
|
float t = u_time * u_speed + u_seed;
|
|
p = sigCamera(p);
|
|
|
|
// The eye wanders, so the composition never sits still even when the arms do.
|
|
vec2 eye = vec2(sin(t * 0.6) * 0.22, cos(t * 0.47) * 0.16);
|
|
vec2 q = p - eye;
|
|
|
|
float r = max(length(q), 1e-4);
|
|
float a = atan(q.y, q.x);
|
|
|
|
// Differential rotation: angular speed falls off with radius, so the arms
|
|
// shear. Bounded rather than 1/r, or the core would spin arbitrarily fast.
|
|
float omega = u_shear / (0.35 + r * 1.6);
|
|
float wound = a + omega * t * 2.0 + log(r + 0.25) * u_winding;
|
|
|
|
// Turbulence breaks the arms into filaments instead of clean spokes.
|
|
wound += (fbm(q * 3.0 + t * 0.4, 4) - 0.5) * u_turbulence * 2.0;
|
|
|
|
float arms = max(float(u_arms), 1.0);
|
|
float band = sin(wound * arms) * 0.5 + 0.5;
|
|
band = pow(band, 1.8);
|
|
|
|
// Density falls off outward, so the frame has a subject.
|
|
float envelope = exp(-r * u_falloff);
|
|
|
|
vec3 col = pal(0) * 0.06;
|
|
col += palRamp(wound * 0.08 + r * 0.2) * band * envelope * 0.9;
|
|
col += pal(4) * pow(band, 4.0) * envelope * 0.5;
|
|
|
|
// The eye itself, in the signature form.
|
|
if (u_core > 0.004) {
|
|
float d = castMain(q / u_core) * u_core;
|
|
col = mix(col, pal(0) * 0.05, smoothstep(0.004, -0.01, d));
|
|
col += pal(3) * inkStroke(d) * 0.8;
|
|
col += pal(4) * exp(-max(d, 0.0) * 18.0) * 0.35;
|
|
}
|
|
|
|
return vec4(inkValue(col), 1.0);
|
|
}
|
|
`,
|
|
};
|
|
|
|
export default vortexDrift;
|