Raise the variety bar to 0.1

Deliberately a target rather than a description of where the library sits. Of
the scenes measured since the region block went in, only Droste Feedback at
0.324 is comfortably over; Plasma Bloom is 0.082, Voronoi Shatter and Apollonian
Gasket 0.062, Moiré Grid 0.047. Most of the library fails this, which is the
point — a bar set where the work already is measures nothing.

Third value in two days, and both previous moves were instrument corrections
rather than changes of mind: the motion block was reading zero for the entire
library, and adding the region block made the total a mean over six blocks
instead of five. Both raised every score, so 0.04 had quietly drifted down
relative to the thing it was judging. Documented as something to re-read off a
fresh gallery whenever the descriptor changes, rather than a number to carry
forward.

The marker now sits at the middle of each meter and the grades land where they
should: 0.047, 0.062 and 0.082 all red, 0.140 amber, 0.324 green.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

flow-state/HOWTO-variety.md

@@ -28,12 +28,15 @@ checks.html?scene=X   the per-scene gate, including `consumes:` lines
 ```
 
 The gallery score is the mean structural distance between a scene's own six
-frames, on the same descriptor the variety harness uses. **Minimum bar: 0.04**
+frames, on the same descriptor the variety harness uses. **Minimum bar: 0.1**
 (`MIN_VARIETY` in `checks/gallery.js`), drawn as a red line. Below it a scene is
 the same picture wherever it appears, and because it is cast into many songs
 that sameness leaks between them — the viewer recognises the shot rather than
 the song.
 
+Most of the library does not clear it. That is deliberate: a bar set where the
+work already is measures nothing.
+
 Some reference points, measured:
 
 ```
@@ -247,7 +250,7 @@ Two more traps, both of which have bitten:
 2. No glow, bloom, grain, haze, chroma or trail parameters.
 3. Element size goes through `stageScale()`.
 4. Placement goes through `stageNode()` unless the composition IS the scene.
-5. Gallery score above 0.04, checked before and after.
+5. Gallery score above 0.1, checked before and after.
 6. The rest of the per-scene battery still passes — especially `distinct`. The
    more scenes share a cast, the easier it is to become one of your neighbours.
 
@@ -261,5 +264,8 @@ Two more traps, both of which have bitten:
 - **Fixed-geometry scenes** have no known route to variety.
 - **The `layout` blindness** for full-frame fields would need a new descriptor
   block measuring cell statistics rather than where structure sits.
-- **The 0.04 bar** is a starting point, set where the flat cluster sat — and set
+- **The bar is a target, not a description.** Most of the library does not clear
-  against scores that were depressed by the motion bug. It deserves re-deriving.
+  0.1 — that is the point of it. It has moved from 0.04 to 0.05 to 0.1
+  as the descriptor gained a block and lost a bug, both of which raised every
+  score. Expect to move it again whenever the descriptor changes, and re-read it
+  off a fresh gallery rather than carrying the old number forward.

flow-state/src/checks/gallery.js

@@ -38,10 +38,19 @@ const THUMB = { width: 256, height: 144 };
  * watches two videos recognises the shot rather than the song. It is a property
  * of the scene, not of the generator, so it is the scene that has to be lifted.
  *
- * 0.04 is a starting bar rather than a derived one. Set where the flat cluster
+ * 0.1, and deliberately a target rather than a description of where the library
- * measurably sits, to be raised as scenes are brought up to it.
+ * currently sits. Most of it does not clear this — of the scenes measured after
+ * the region block went in, only Droste Feedback at 0.324 is comfortably over,
+ * with Plasma Bloom at 0.082 and Voronoi Shatter at 0.062 still short. A bar set
+ * where the work already is measures nothing.
+ *
+ * It has moved twice for instrument reasons rather than taste — the motion block
+ * was reading zero for the whole library, and adding the region block made the
+ * total a mean over six rather than five — and both raised every score. Expect
+ * to re-read it off a fresh gallery whenever the descriptor changes, rather than
+ * carrying the old number forward.
  */
-export const MIN_VARIETY = 0.04;
+export const MIN_VARIETY = 0.1;
 
 /**
  * Six contexts, one per song: everything a scene is handed when it is cast.

flow-state/src/scenes/registry.js

@@ -69,6 +69,7 @@ import { isometricBlocks } from './shader/isometric-blocks.js';
 import { halftoneMisprint } from './shader/halftone-misprint.js';
 import { drosteFeedback } from './shader/droste-feedback.js';
 import { analogWow } from './shader/analog-wow.js';
+import { mountainFlight } from './shader/mountain-flight.js';
 
 /**
  * The scene library. Families exist so the arc driver can choose by section
@@ -163,6 +164,7 @@ const MODULES = [
     constellation,
     soloist,
     swarm,
+    mountainFlight,
 ];
 
 const errors = [];

flow-state/src/scenes/shader/mountain-flight.js

@@ -0,0 +1,142 @@
+// Structural family: a flight through mountains. A real perspective camera
+// travelling forward over a raymarched heightfield — peaks rise, pass to either
+// side and occlude what is behind them, with a snowline near the top and the
+// ridge silhouettes drawn in the song's hand.
+//
+// Ridge Terrain is the neighbour, and it is the flat version of this: parallax
+// bands of 1D noise that slide sideways and can never hide each other, because
+// there is no depth for them to hide in. Here the image is a 3D field sampled
+// along the ray, so the motion is INTO the frame rather than across it, valleys
+// open and close as the camera passes through them, and a near peak eats a far
+// one. The massifs themselves are the song's protagonist, extruded: a hollow
+// cast makes calderas, a notched one makes star-shaped ridges.
+
+export const mountainFlight = {
+    name: 'Mountain Flight',
+    family: 'structural',
+    kind: 'fragment',
+    // Personality: see look/Personality.js. Identity: see look/Identity.js.
+    consumes: ['cast', 'ink', 'staging'],
+    traits: ['camera', 'space', 'style'],
+
+    params: {
+        relief:   { type: 'float', range: [0.15, 1.4],  default: 0.55, uniform: 'u_relief', bias: 'energy' },
+        rugged:   { type: 'float', range: [0.15, 1.1],  default: 0.45, uniform: 'u_rug', bias: 'density' },
+        ridges:   { type: 'int',   range: [2, 5],       default: 4,    uniform: 'u_oct', bias: 'density' },
+        massif:   { type: 'float', range: [0.1, 0.9],   default: 0.5,  uniform: 'u_massif' },
+        span:     { type: 'float', range: [4, 16],      default: 8.0,  uniform: 'u_span', bias: 'density' },
+        altitude: { type: 'float', range: [0.15, 2.2],  default: 0.7,  uniform: 'u_alt', slowAxis: true },
+        snowline: { type: 'float', range: [0.15, 1.1],  default: 0.55, uniform: 'u_snow', bias: 'energy' },
+        speed:    { type: 'float', range: [0.1, 2.5],   default: 0.8,  uniform: 'u_speed', bias: 'motion', rate: true },
+        palette:  { type: 'palette', count: 6 },
+    },
+
+    reactive: {
+        relief:   { feature: 'bandLow',  amount: 0.22, response: 'smooth' },
+        snowline: { feature: 'bandHigh', amount: 0.2,  response: 'smooth' },
+        altitude: { feature: 'bandSub',  amount: 0.15, response: 'smooth' },
+    },
+
+    shader: `
+// The massif standing in the world cell around w: the song's protagonist, used
+// as a PLAN rather than a picture — its footprint is extruded into a mountain.
+// Kept strictly inside its own cell so one sample of one cell is the whole
+// answer, which is what makes it affordable inside the march.
+float massifH(vec2 w) {
+    vec2 cell = floor(w / u_span);
+    vec2 local = w - (cell + 0.5) * u_span;
+
+    // Which node of the song's lattice this cell got, and how big it stands.
+    vec3 node = stageNode(floor(hash12(cell) * 7.0), 8.0);
+    vec2 at = clamp(node.xy, -1.0, 1.0) * u_span * 0.18;
+    float s = u_span * 0.2 * clamp(u_massif * node.z, 0.08, 1.1);
+
+    float d = castMain((local - at) / s) * s;
+    // Flanks fall away from the footprint's edge; the summit is its middle.
+    float m = sat(-d / max(s * 0.9, 1e-3));
+    return pow(m, 0.7) * u_relief * 1.7;
+}
+
+float terrainH(vec2 w) {
+    // The song's element size is the size of the whole landscape's vocabulary:
+    // a few enormous massifs, or a crowd of small ones.
+    vec2 q = w * u_rug / max(stageScale(), 0.25);
+
+    float sum = 0.0, norm = 0.0, amp = 1.0;
+    for (int i = 0; i < 5; i++) {
+        if (i >= u_oct) break;
+        // Ridged, not billowy: mountains have crests.
+        float n = 1.0 - abs(vnoise(q) * 2.0 - 1.0);
+        sum += n * n * amp;
+        norm += amp;
+        q = rot(0.63) * q * 2.03;
+        amp *= 0.45;
+    }
+    return (sum / max(norm, 1e-3)) * u_relief + massifH(w);
+}
+
+vec4 scene(vec2 uv, vec2 p) {
+    float t = u_time * u_speed + u_seed;
+    p = sigCamera(p);
+
+    // The camera rides a fixed height over whatever it is flying across, so a
+    // tall massif lifts the flight path instead of swallowing it.
+    vec3 ro = vec3(u_seed * 3.7, 0.0, t * 4.0);
+    ro.y = terrainH(ro.xz) + u_alt * (1.0 + stageScale() * 0.3);
+
+    // The track's horizon decides how far down the camera is looking.
+    vec3 rd = normalize(vec3(p.x, p.y - sigHorizonY() * 0.5, 1.6));
+
+    float dist = 0.4;
+    float hit = 0.0;
+    float gap = 0.0;
+    float grazed = 1e3;                 // closest the ray came, per unit distance
+
+    // A march ends on its hit or its far plane, not on a param.
+    // lint: fixed-cost
+    for (int i = 0; i < 72; i++) {
+        vec3 at = ro + rd * dist;
+        gap = at.y - terrainH(at.xz);
+        grazed = min(grazed, gap / max(dist, 1.0));
+        if (gap < 0.002 * dist) { hit = 1.0; break; }
+        // Cone stepping: safe near the surface, cheap out at the far end.
+        dist += max(gap * 0.5, 0.03 + dist * 0.02);
+        if (dist > 46.0) break;
+    }
+
+    float fog = sat(dist / 46.0);
+    vec3 col;
+
+    if (hit > 0.5) {
+        vec3 at = ro + rd * dist;
+        float e = 0.02 + dist * 0.006;
+        vec3 nrm = normalize(vec3(
+            terrainH(at.xz - vec2(e, 0.0)) - terrainH(at.xz + vec2(e, 0.0)),
+            2.0 * e,
+            terrainH(at.xz - vec2(0.0, e)) - terrainH(at.xz + vec2(0.0, e))));
+
+        vec3 sun = normalize(vec3(0.55, 0.42, -0.5));
+        float diff = sat(dot(nrm, sun));
+
+        float elev = sat(at.y / max(u_relief * 2.2, 0.2));
+        // Snow lies high, and only where the slope will hold it.
+        float snow = smoothstep(u_snow, u_snow + 0.16, elev * (0.45 + 0.75 * nrm.y));
+
+        vec3 rock = mix(pal(2), pal(3), sat(elev * 1.3));
+        col = mix(rock, pal(5), snow);
+        col *= 0.22 + 0.9 * diff;
+        col += pal(1) * 0.12 * sat(nrm.y);      // sky bounce into the flats
+    } else {
+        col = mix(pal(1) * 0.45, pal(0) * 0.22, sat(rd.y * 2.2 + 0.15));
+        fog = 0.85;
+        // The ridgeline the sky is cut against, drawn at the song's weight.
+        col += pal(4) * inkStroke(grazed * 0.6) * 0.5;
+    }
+
+    col = sigAir(col, p, fog);
+    return vec4(inkValue(col), 1.0);
+}
+`,
+};
+
+export default mountainFlight;