Antipodal Nervous System

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params (23)

feed 0.05

kill 0.06

simSpeed 1.10

seedRate 0.70

traceLife 1.00

drift 1.05

motion 1.00

swirl 1.15

warp 1.10

trail 1.00

sparkle 0.82

hueShift 0.11

stir 0.72

etch 0.88

flow 0.68

fuse 0.72

deform 1.10

fracture 0.62

filament 0.92

nodeSize 0.01

exposure 1.08

horizon 0.08

anomaly 1.00

.fs source · isf not running

/*{
  "DESCRIPTION": "Antipodal Nervous System: Soft Asterism develops a pair of moving event horizons. Fluid-authored constellations fall into one aperture, re-emerge mirrored from the other, and continue as reversed-color phantom nerves while each horizon shows a live image of its antipode.",
  "CREDIT": "glslop agent (Codex), mutating Soft Asterism",
  "CATEGORIES": ["feedback", "fluid", "constellation", "wormhole", "reaction-diffusion", "spectral"],
  "INPUTS": [
    { "NAME": "feed",       "TYPE": "float", "DEFAULT": 0.054,   "MIN": 0.010, "MAX": 0.080 },
    { "NAME": "kill",       "TYPE": "float", "DEFAULT": 0.061,   "MIN": 0.030, "MAX": 0.075 },
    { "NAME": "simSpeed",   "TYPE": "float", "DEFAULT": 1.10,    "MIN": 0.1,   "MAX": 2.0 },
    { "NAME": "seedRate",   "TYPE": "float", "DEFAULT": 0.70,    "MIN": 0.0,   "MAX": 1.0 },
    { "NAME": "traceLife",  "TYPE": "float", "DEFAULT": 0.9989,  "MIN": 0.990, "MAX": 0.9998 },
    { "NAME": "drift",      "TYPE": "float", "DEFAULT": 1.05,    "MIN": 0.0,   "MAX": 2.0 },
    { "NAME": "motion",     "TYPE": "float", "DEFAULT": 1.0,     "MIN": 0.0,   "MAX": 2.5 },
    { "NAME": "swirl",      "TYPE": "float", "DEFAULT": 1.15,    "MIN": 0.0,   "MAX": 2.0 },
    { "NAME": "warp",       "TYPE": "float", "DEFAULT": 1.10,    "MIN": 0.0,   "MAX": 2.0 },
    { "NAME": "trail",      "TYPE": "float", "DEFAULT": 0.9968,  "MIN": 0.97,  "MAX": 0.9998 },
    { "NAME": "sparkle",    "TYPE": "float", "DEFAULT": 0.82,    "MIN": 0.0,   "MAX": 1.5 },
    { "NAME": "hueShift",   "TYPE": "float", "DEFAULT": 0.11,    "MIN": 0.0,   "MAX": 1.0 },
    { "NAME": "stir",       "TYPE": "float", "DEFAULT": 0.72,    "MIN": 0.0,   "MAX": 1.5 },
    { "NAME": "etch",       "TYPE": "float", "DEFAULT": 0.88,    "MIN": 0.0,   "MAX": 1.5 },
    { "NAME": "flow",       "TYPE": "float", "DEFAULT": 0.68,    "MIN": 0.0,   "MAX": 1.5 },
    { "NAME": "fuse",       "TYPE": "float", "DEFAULT": 0.72,    "MIN": 0.0,   "MAX": 1.0 },
    { "NAME": "deform",     "TYPE": "float", "DEFAULT": 1.10,    "MIN": 0.0,   "MAX": 2.0 },
    { "NAME": "fracture",   "TYPE": "float", "DEFAULT": 0.62,    "MIN": 0.0,   "MAX": 1.5 },
    { "NAME": "filament",   "TYPE": "float", "DEFAULT": 0.92,    "MIN": 0.0,   "MAX": 1.6 },
    { "NAME": "nodeSize",   "TYPE": "float", "DEFAULT": 0.013,   "MIN": 0.005, "MAX": 0.035 },
    { "NAME": "exposure",   "TYPE": "float", "DEFAULT": 1.08,    "MIN": 0.5,   "MAX": 1.8 },
    { "NAME": "horizon",    "TYPE": "float", "DEFAULT": 0.082,   "MIN": 0.035, "MAX": 0.14 },
    { "NAME": "anomaly",    "TYPE": "float", "DEFAULT": 1.0,     "MIN": 0.0,   "MAX": 1.5 }
  ],
  "PASSES": [
    { "TARGET": "chem",  "PERSISTENT": true, "FLOAT": true },
    { "TARGET": "paint", "PERSISTENT": true, "FLOAT": true },
    {}
  ]
}*/

#define TAU 6.28318530718
#define NODES 14

float hash11(float p) {
  return fract(sin(p * 127.1) * 43758.5453123);
}

float hash21(vec2 p) {
  p = fract(p * vec2(123.34, 456.21));
  p += dot(p, p + 45.32);
  return fract(p.x * p.y);
}

vec3 oilPalette(float t) {
  return 0.52 + 0.48 * cos(TAU * (t + hueShift + vec3(0.02, 0.31, 0.61)));
}

vec3 chemPalette(float t) {
  return 0.50 + 0.50 * cos(TAU * (t + vec3(0.08, 0.27, 0.55)));
}

float luminance(vec3 c) {
  return dot(c, vec3(0.299, 0.587, 0.114));
}

vec2 chemistry(vec2 uv) {
  return IMG_NORM_PIXEL(chem, uv).rg;
}

float distSeg(vec2 p, vec2 a, vec2 b) {
  vec2 pa = p - a;
  vec2 ba = b - a;
  float h = clamp(dot(pa, ba) / max(dot(ba, ba), 0.00001), 0.0, 1.0);
  return length(pa - ba * h);
}

float blob(vec2 uv, vec2 center, float size, float aspect) {
  vec2 d = uv - center;
  d.x *= aspect;
  return 1.0 - smoothstep(size * 0.25, size, length(d));
}

vec2 vortex(vec2 p, vec2 center, float spin, float radius) {
  vec2 d = p - center;
  float influence = exp(-dot(d, d) / max(radius * radius, 0.001));
  return vec2(-d.y, d.x) * influence * spin;
}

// This same field advects the liquid and bends the asterism. The geometry is
// therefore downstream of the fluid, reversing the old armature relationship.
vec2 liquidField(vec2 p, float t) {
  vec2 a = vec2(0.29 * cos(t * 0.31), 0.24 * sin(t * 0.43));
  vec2 b = vec2(0.31 * cos(t * 0.27 + 2.8), 0.29 * sin(t * 0.37 + 1.6));
  vec2 c = vec2(0.18 * sin(t * 0.57 + 0.7), 0.33 * cos(t * 0.23 - 0.5));
  vec2 v = vortex(p, a, 2.8, 0.34)
         + vortex(p, b, -2.35, 0.38)
         + vortex(p, c, 1.75, 0.29);
  v += 0.055 * vec2(
    sin(p.y * 8.0 + p.x * 2.0 + t * 0.71),
    cos(p.x * 7.0 - p.y * 3.0 - t * 0.59)
  );
  v += 0.025 * vec2(sin(p.y * 23.0 - t), cos(p.x * 19.0 + t * 0.83));
  return v;
}

vec2 portalA(float t) {
  return vec2(-0.27 + 0.055 * cos(t * 0.23), 0.13 + 0.12 * sin(t * 0.31));
}

vec2 portalB(float t) {
  return vec2(0.25 + 0.065 * sin(t * 0.19), -0.10 + 0.14 * cos(t * 0.27));
}

vec2 quarterTurn(vec2 p) {
  return vec2(-p.y, p.x);
}

vec2 restNode(float i, float t) {
  float angle = i * 2.39996323 + 0.055 * t;
  float radius = 0.16 + 0.31 * (0.5 + 0.5 * sin(i * 1.731 + t * 0.09));
  vec2 p = radius * vec2(cos(angle), sin(angle));
  p += 0.105 * vec2(sin(i * 1.19 - t * 0.13), cos(i * 1.47 + t * 0.11));
  return p;
}

vec2 sculptNode(float i, float t, float aspect) {
  vec2 p = restNode(i, t);
  vec2 uv = vec2(p.x / aspect, p.y) + 0.5;
  vec2 e = vec2(0.013);

  float mR = luminance(IMG_NORM_PIXEL(paint, uv + vec2(e.x, 0.0)).rgb);
  float mL = luminance(IMG_NORM_PIXEL(paint, uv - vec2(e.x, 0.0)).rgb);
  float mU = luminance(IMG_NORM_PIXEL(paint, uv + vec2(0.0, e.y)).rgb);
  float mD = luminance(IMG_NORM_PIXEL(paint, uv - vec2(0.0, e.y)).rgb);
  float cR = IMG_NORM_PIXEL(chem, uv + vec2(e.x, 0.0)).b;
  float cL = IMG_NORM_PIXEL(chem, uv - vec2(e.x, 0.0)).b;
  float cU = IMG_NORM_PIXEL(chem, uv + vec2(0.0, e.y)).b;
  float cD = IMG_NORM_PIXEL(chem, uv - vec2(0.0, e.y)).b;

  vec2 pressure = vec2(mR - mL, mU - mD) * 1.9;
  pressure += vec2(-(cU - cD), cR - cL) * 0.95;
  pressure /= 1.0 + 3.5 * length(pressure);
  vec2 motionField = liquidField(p, t) + pressure;
  motionField /= 1.0 + 1.8 * length(motionField);
  return p + motionField * (0.42 * deform);
}

vec2 quadPoint(vec2 a, vec2 c, vec2 b, float t) {
  vec2 ac = mix(a, c, t);
  vec2 cb = mix(c, b, t);
  return mix(ac, cb, t);
}

float quadDist(vec2 p, vec2 a, vec2 c, vec2 b) {
  float d = 10.0;
  vec2 last = a;
  for (int k = 1; k <= 5; k++) {
    float s = float(k) / 5.0;
    vec2 here = quadPoint(a, c, b, s);
    d = min(d, distSeg(p, last, here));
    last = here;
  }
  return d;
}

void softAsterism(
  vec2 p, float t, float aspect,
  out float nodeCore, out float nodeHalo,
  out float strandCore, out float strandHalo,
  out float beads, out float ghosts
) {
  nodeCore = 0.0;
  nodeHalo = 0.0;
  strandCore = 0.0;
  strandHalo = 0.0;
  beads = 0.0;
  ghosts = 0.0;

  for (int i = 0; i < NODES; i++) {
    float fi = float(i);
    vec2 seed = sculptNode(fi, t, aspect);
    float dn = length(p - seed);
    nodeCore += 1.0 - smoothstep(nodeSize * 0.34, nodeSize, dn);
    nodeHalo += exp(-dn * dn / max(nodeSize * nodeSize * 15.0, 0.00001));

    // Each star grows a pair of streamlines by integrating the liquid velocity
    // forward and backward. They are connections authored by flow, not by a
    // geometric nearest-neighbour rule; their destinations keep changing.
    float rnd = hash11(fi * 19.17 + 3.4);
    for (int direction = 0; direction < 2; direction++) {
      float signDir = direction == 0 ? 1.0 : -1.0;
      vec2 last = seed;
      float inversion = 0.0;
      float travel = fract(t * (0.075 + rnd * 0.035) + rnd + float(direction) * 0.37) * 9.0;

      for (int k = 0; k < 9; k++) {
        float fk = float(k);
        vec2 velocity = liquidField(last, t + fk * 0.025 * signDir);
        velocity += 0.024 * vec2(
          sin(fi * 2.1 + fk * 0.73 + t * 0.31),
          cos(fi * 1.7 - fk * 0.61 - t * 0.27)
        );
        vec2 tangent = velocity / max(length(velocity), 0.0001);
        vec2 normal = vec2(-tangent.y, tangent.x);
        float stepLength = 0.036 + 0.014 * rnd + 0.004 * sin(fi + fk * 1.3);
        vec2 here = last + signDir * tangent * stepLength;
        here += normal * sin(fi * 1.9 + fk * 1.13 + t * 0.7) * 0.006 * deform;
        vec2 arrival = here;

        float fatigue = 0.5 + 0.5 * sin(t * (0.53 + rnd * 0.19) + fi * 1.31 + fk * 0.77);
        float alive = 1.0 - smoothstep(0.54, 0.93, fracture * fatigue);
        float d = distSeg(p, last, arrival);
        float core = 1.0 - smoothstep(0.0010, 0.0040, d);
        float halo = 1.0 - smoothstep(0.003, 0.026, d);
        strandCore += core * alive * (1.0 - 0.35 * inversion);
        strandHalo += halo * alive * (1.0 - 0.20 * inversion);
        ghosts += halo * (1.0 - alive) * (0.10 + 0.30 * fatigue);
        ghosts += (core * 1.35 + halo * 0.22) * inversion * alive * anomaly;

        float activeSegment = 1.0 - smoothstep(0.12, 0.55, abs(fk - floor(travel)));
        vec2 beadPos = mix(last, arrival, fract(travel));
        float beadD = length(p - beadPos);
        beads += exp(-beadD * beadD / 0.000045) * activeSegment * alive;

        float snap = (1.0 - alive) * smoothstep(0.82, 1.0, fatigue);
        vec2 recoil = normal * (0.008 + 0.012 * fatigue);
        float d1 = length(p - 0.5 * (last + arrival) - recoil);
        float d2 = length(p - 0.5 * (last + arrival) + recoil);
        beads += (exp(-d1 * d1 / 0.000025) + exp(-d2 * d2 / 0.000025)) * snap;

        // Crossing an aperture breaks the visible segment at the horizon, then
        // rotates and mirrors its continuation out of the antipodal aperture.
        vec2 pa = portalA(t);
        vec2 pb = portalB(t);
        vec2 localA = arrival - pa;
        vec2 localB = arrival - pb;
        float hitA = step(length(localA), horizon * 0.76) * step(0.5, anomaly);
        float hitB = step(length(localB), horizon * 0.76) * step(0.5, anomaly);
        vec2 exitA = pb + normalize(quarterTurn(localA) + vec2(0.0001))
                         * (horizon * 1.12 + length(localA) * 0.18);
        vec2 exitB = pa + normalize(-quarterTurn(localB) + vec2(0.0001))
                         * (horizon * 1.12 + length(localB) * 0.18);
        here = mix(arrival, exitA, hitA);
        here = mix(here, exitB, hitB);
        inversion = mod(inversion + hitA + hitB, 2.0);
        last = here;
      }
    }
  }
}

void main() {
  vec2 uv = isf_FragNormCoord;
  vec2 px = 1.0 / RENDERSIZE;
  float aspect = RENDERSIZE.x / RENDERSIZE.y;
  vec2 p = uv - 0.5;
  p.x *= aspect;
  float t = TIME * motion;

  if (PASSINDEX == 0) {
    vec3 state = IMG_NORM_PIXEL(chem, uv).rgb;
    vec2 c = state.rg;

    if (FRAMEINDEX < 2 || dot(c, c) < 0.000001) {
      float cellular = sin(p.x * 26.0) + sin(p.y * 31.0)
                     + sin((p.x - p.y) * 18.0) + cos(length(p) * 39.0);
      float initial = smoothstep(1.45, 2.65, cellular)
                    * (1.0 - smoothstep(0.18, 0.68, length(p)));
      c = mix(vec2(1.0, 0.0), vec2(0.49, 0.31), initial);
    }

    vec3 metal = IMG_NORM_PIXEL(paint, uv).rgb;
    float m = luminance(metal);
    float mR = luminance(IMG_NORM_PIXEL(paint, uv + vec2(px.x, 0.0)).rgb);
    float mU = luminance(IMG_NORM_PIXEL(paint, uv + vec2(0.0, px.y)).rgb);
    vec2 metalCurl = vec2(-(mU - m), mR - m);
    vec2 advect = liquidField(p, t) * (0.0028 * drift);
    advect += metalCurl * (0.72 * stir);
    advect.x /= aspect;
    vec2 sampleUV = uv - advect;

    vec2 lap = -c;
    lap += 0.20 * chemistry(sampleUV + vec2(px.x, 0.0));
    lap += 0.20 * chemistry(sampleUV - vec2(px.x, 0.0));
    lap += 0.20 * chemistry(sampleUV + vec2(0.0, px.y));
    lap += 0.20 * chemistry(sampleUV - vec2(0.0, px.y));
    lap += 0.05 * chemistry(sampleUV + px);
    lap += 0.05 * chemistry(sampleUV - px);
    lap += 0.05 * chemistry(sampleUV + vec2(px.x, -px.y));
    lap += 0.05 * chemistry(sampleUV + vec2(-px.x, px.y));

    float u = c.r;
    float v = c.g;
    float reaction = u * v * v;
    float stepSize = min(TIMEDELTA * 60.0, 1.25) * simSpeed;
    float localFeed = feed * (0.91 + 0.09 * sin(TIME * 1.27));
    u += (0.16 * lap.r - reaction + localFeed * (1.0 - u)) * stepSize;
    v += (0.08 * lap.g + reaction - (kill + localFeed) * v) * stepSize;

    // Autonomous chemistry: these moving wounds belong to the liquid system,
    // not to the constellation. The constellation has no seeding authority.
    vec2 oa = vec2(0.5 + 0.27 * cos(t * 0.37), 0.5 + 0.23 * sin(t * 0.51));
    vec2 ob = vec2(0.5 + 0.29 * cos(t * 0.29 + 2.7), 0.5 + 0.26 * sin(t * 0.41 + 1.3));
    vec2 oc = vec2(0.5 + 0.17 * sin(t * 0.67), 0.5 + 0.31 * cos(t * 0.25 - 0.8));
    float fresh = blob(uv, oa, 0.038, aspect);
    fresh += 0.85 * blob(uv, ob, 0.032, aspect);
    fresh += 0.70 * blob(uv, oc, 0.026, aspect);
    fresh = clamp(fresh * seedRate, 0.0, 1.0);
    float metalSeed = smoothstep(0.28, 0.78, m) * stir;
    v = max(v, fresh * 0.43 + metalSeed * 0.22);
    u = mix(u, 0.48, clamp(fresh * 0.72 + metalSeed * 0.24, 0.0, 0.88));

    float memory = state.b * 0.73;
    memory += IMG_NORM_PIXEL(chem, uv + vec2(px.x, 0.0)).b * 0.0675;
    memory += IMG_NORM_PIXEL(chem, uv - vec2(px.x, 0.0)).b * 0.0675;
    memory += IMG_NORM_PIXEL(chem, uv + vec2(0.0, px.y)).b * 0.0675;
    memory += IMG_NORM_PIXEL(chem, uv - vec2(0.0, px.y)).b * 0.0675;
    memory *= pow(traceLife, stepSize);
    memory = max(memory, fresh * 0.72);
    memory = max(memory, smoothstep(0.08, 0.32, v) * 0.22);
    memory = max(memory, metalSeed * 0.18);

    gl_FragColor = vec4(clamp(u, 0.0, 1.0), clamp(v, 0.0, 1.0), clamp(memory, 0.0, 1.0), 1.0);

  } else if (PASSINDEX == 1) {
    float frameStep = min(TIMEDELTA * 60.0, 2.0);
    vec2 vel = liquidField(p, t);

    float v0 = IMG_NORM_PIXEL(chem, uv).g;
    float vR = IMG_NORM_PIXEL(chem, uv + vec2(px.x, 0.0)).g;
    float vU = IMG_NORM_PIXEL(chem, uv + vec2(0.0, px.y)).g;
    vec2 chemCurl = vec2(-(vU - v0), vR - v0);
    vel += chemCurl * (30.0 * flow);
    vel *= swirl;
    vel.x /= aspect;

    vec2 back = uv - vel * (0.015 * frameStep);
    vec3 old = IMG_NORM_PIXEL(paint, back).rgb * 0.64;
    old += IMG_NORM_PIXEL(paint, back + vec2(px.x, 0.0)).rgb * 0.085;
    old += IMG_NORM_PIXEL(paint, back - vec2(px.x, 0.0)).rgb * 0.085;
    old += IMG_NORM_PIXEL(paint, back + vec2(0.0, px.y)).rgb * 0.085;
    old += IMG_NORM_PIXEL(paint, back - vec2(0.0, px.y)).rgb * 0.085;
    old *= pow(trail, frameStep);

    vec2 a = vec2(0.29 * cos(t * 0.31), 0.24 * sin(t * 0.43));
    vec2 b = vec2(0.31 * cos(t * 0.27 + 2.8), 0.29 * sin(t * 0.37 + 1.6));
    vec2 cC = vec2(0.18 * sin(t * 0.57 + 0.7), 0.33 * cos(t * 0.23 - 0.5));
    float da = length(p - a);
    float db = length(p - b);
    float dc = length(p - cC);
    float sourceA = 1.0 - smoothstep(0.012, 0.065, da);
    float sourceB = 1.0 - smoothstep(0.010, 0.054, db);
    float sourceC = 1.0 - smoothstep(0.008, 0.043, dc);
    float bridge = 1.0 - smoothstep(0.012, 0.052, distSeg(p, a, b));
    bridge *= smoothstep(0.0, 0.22, min(da, db));

    vec3 fresh = oilPalette(t * 0.025 + 0.08) * sourceA;
    fresh += oilPalette(t * 0.025 + 0.51) * sourceB;
    fresh += oilPalette(t * 0.025 + 0.83) * sourceC;
    fresh += mix(vec3(0.02, 0.62, 0.82), vec3(0.95, 0.18, 0.42),
                 0.5 + 0.5 * sin(t * 0.4)) * bridge * 0.18;

    float chm = IMG_NORM_PIXEL(chem, uv).b;
    float chemicalBody = smoothstep(0.025, 0.58, chm);
    float reactionFront = smoothstep(0.015, 0.24, v0);
    fresh += chemPalette(v0 * 2.7 + chm * 0.42) * chemicalBody * (0.44 * etch);
    fresh += oilPalette(chm * 0.7 + 0.28) * reactionFront * 0.12;

    float boundary = smoothstep(0.0, 0.025, uv.x)
                   * smoothstep(0.0, 0.025, 1.0 - uv.x)
                   * smoothstep(0.0, 0.025, uv.y)
                   * smoothstep(0.0, 0.025, 1.0 - uv.y);
    vec3 next = max(old, fresh * 0.47) * boundary;
    vec3 hot = max(next - vec3(0.72), vec3(0.0));
    next = min(next, vec3(0.72)) + hot / (1.0 + hot);
    gl_FragColor = vec4(clamp(next, 0.0, 1.35), 1.0);

  } else {
    vec3 c0 = IMG_NORM_PIXEL(paint, uv).rgb;
    vec3 cR = IMG_NORM_PIXEL(paint, uv + vec2(px.x * 1.8, 0.0)).rgb;
    vec3 cL = IMG_NORM_PIXEL(paint, uv - vec2(px.x * 1.8, 0.0)).rgb;
    vec3 cU = IMG_NORM_PIXEL(paint, uv + vec2(0.0, px.y * 1.8)).rgb;
    vec3 cD = IMG_NORM_PIXEL(paint, uv - vec2(0.0, px.y * 1.8)).rgb;
    float lum = luminance(c0);
    vec2 grad = vec2(luminance(cR) - luminance(cL), luminance(cU) - luminance(cD));
    float rim = clamp(length(grad) * 38.0, 0.0, 1.0);
    float body = smoothstep(0.018, 0.46, lum);
    float reflection = 0.5 + 0.5 * sin(17.0 * uv.x - 11.0 * uv.y + t * 0.48 + lum * 9.0);
    float glint = pow(max(reflection * rim, 0.0), 3.0) * sparkle;

    vec3 dispersed = vec3(cR.r, c0.g, cL.b);
    vec3 liquid = mix(c0, dispersed, 0.52);
    liquid *= 0.20 + 1.42 * lum;
    liquid += oilPalette(0.13 + lum * 0.34) * rim * (0.42 + 0.36 * sparkle);
    liquid += vec3(0.90, 0.96, 1.0) * glint;

    vec3 chm = IMG_NORM_PIXEL(chem, uv).rgb;
    float ink = smoothstep(0.018, 0.30, chm.g);
    float memory = smoothstep(0.025, 0.62, chm.b);
    float gx = length(IMG_NORM_PIXEL(chem, uv + vec2(px.x, 0.0)).rg - chm.rg);
    float gy = length(IMG_NORM_PIXEL(chem, uv + vec2(0.0, px.y)).rg - chm.rg);
    float chemEdge = clamp((gx + gy) * 20.0, 0.0, 1.0);
    vec3 spectral = chemPalette(chm.g * 2.6 + chm.b * 0.35);
    spectral *= memory * (0.24 + 0.42 * fuse) + ink * 0.08;
    spectral += oilPalette(chm.b * 0.48 + 0.66) * chemEdge * 0.32;

    vec3 bg = mix(vec3(0.002, 0.006, 0.018), vec3(0.012, 0.004, 0.020), uv.y);
    float grain = hash21(floor(gl_FragCoord.xy));
    float star = smoothstep(0.9965, 1.0, grain);
    bg += star * vec3(0.35, 0.58, 0.82) * (0.25 + 0.45 * sin(t * 1.7 + grain * 40.0));

    vec3 field = bg * (1.0 - body * 0.62) + liquid + spectral;
    field *= 0.72 + 0.28 * smoothstep(0.0, 0.22, body + memory);

    // Each dark lens contains a live, quarter-turned view through the opposite
    // fluid region. Green and fuchsia are deliberately alien to the parent.
    vec2 pa = portalA(t);
    vec2 pb = portalB(t);
    vec2 la = p - pa;
    vec2 lb = p - pb;
    float da = length(la);
    float db = length(lb);
    float holeA = 1.0 - smoothstep(horizon * 0.72, horizon * 0.94, da);
    float holeB = 1.0 - smoothstep(horizon * 0.72, horizon * 0.94, db);
    float lensA = 1.0 - smoothstep(horizon, horizon * 1.75, da);
    float lensB = 1.0 - smoothstep(horizon, horizon * 1.75, db);
    float ringA = 1.0 - smoothstep(0.002, 0.010, abs(da - horizon));
    float ringB = 1.0 - smoothstep(0.002, 0.010, abs(db - horizon));
    vec2 throughA = pb + quarterTurn(la) * 0.82;
    vec2 throughB = pa - quarterTurn(lb) * 0.82;
    vec2 uvA = vec2(throughA.x / aspect, throughA.y) + 0.5;
    vec2 uvB = vec2(throughB.x / aspect, throughB.y) + 0.5;
    vec3 visionA = IMG_NORM_PIXEL(paint, uvA).gbr;
    vec3 visionB = IMG_NORM_PIXEL(paint, uvB).brg;
    visionA = visionA * 1.25 + vec3(0.02, 0.36, 0.10);
    visionB = visionB * 1.25 + vec3(0.40, 0.01, 0.19);
    float portalMix = clamp(anomaly, 0.0, 1.0);
    field = mix(field, visionA, holeA * portalMix * 0.88);
    field = mix(field, visionB, holeB * portalMix * 0.88);
    field *= 1.0 - (holeA + holeB) * (0.20 + 0.20 * portalMix);
    field += vec3(0.01, 0.32, 0.12) * lensA * (1.0 - holeA) * anomaly * 0.23;
    field += vec3(0.40, 0.01, 0.22) * lensB * (1.0 - holeB) * anomaly * 0.23;

    float nCore, nHalo, sCore, sHalo, beadMask, ghostMask;
    softAsterism(p, t, aspect, nCore, nHalo, sCore, sHalo, beadMask, ghostMask);
    float localEnergy = clamp(lum * 1.7 + memory * 0.55 + rim * 0.35, 0.0, 1.0);
    vec3 coolWire = mix(vec3(0.05, 0.78, 1.0), vec3(0.45, 0.08, 0.86), localEnergy);
    vec3 hotWire = mix(vec3(0.30, 0.90, 1.0), vec3(1.0, 0.44, 0.12), localEnergy * localEnergy);

    // Hairline cores sit inside broad colored interference halos. Failed links
    // remain as dim afterimages, making reconnection visible instead of abrupt.
    field += coolWire * sHalo * filament * (0.10 + 0.28 * localEnergy);
    vec3 phantom = mix(vec3(0.10, 1.0, 0.32), vec3(1.0, 0.03, 0.58),
                       0.5 + 0.5 * sin(p.x * 9.0 - p.y * 7.0 + t));
    field += phantom * ghostMask * (0.16 * fracture + 0.36 * anomaly);
    field += hotWire * sCore * filament * (0.42 + 0.42 * localEnergy);
    field += vec3(0.92, 0.98, 1.0) * sCore * filament * 0.20;
    field += coolWire * nHalo * (0.18 + 0.25 * localEnergy);
    field += hotWire * nCore * 0.72;
    field += vec3(1.0, 0.98, 0.91) * (nCore * nCore + beadMask * 0.92);
    field += oilPalette(0.76 + t * 0.02) * beadMask * sparkle * 0.48;
    field += vec3(0.16, 1.0, 0.42) * ringA * anomaly * (0.48 + 0.35 * sparkle);
    field += vec3(1.0, 0.06, 0.48) * ringB * anomaly * (0.48 + 0.35 * sparkle);
    field += vec3(0.92, 1.0, 0.95) * (ringA + ringB) * 0.20;

    // Fluid lenses eclipse the node centers; stars feel embedded in the liquid,
    // not pasted over it.
    field *= 1.0 - clamp(nCore * 0.18 * body, 0.0, 0.32);
    field *= exposure;
    field *= 1.0 - 0.22 * dot(p, p);
    field = field / (1.0 + 0.46 * field);
    field = pow(max(field, 0.0), vec3(0.88));
    gl_FragColor = vec4(field, 1.0);
  }
}

/*{
  "DESCRIPTION": "Antipodal Nervous System: Soft Asterism develops a pair of moving event horizons. Fluid-authored constellations fall into one aperture, re-emerge mirrored from the other, and continue as reversed-color phantom nerves while each horizon shows a live image of its antipode.",
  "CREDIT": "glslop agent (Codex), mutating Soft Asterism",
  "CATEGORIES": ["feedback", "fluid", "constellation", "wormhole", "reaction-diffusion", "spectral"],
  "INPUTS": [
    { "NAME": "feed",       "TYPE": "float", "DEFAULT": 0.054,   "MIN": 0.010, "MAX": 0.080 },
    { "NAME": "kill",       "TYPE": "float", "DEFAULT": 0.061,   "MIN": 0.030, "MAX": 0.075 },
    { "NAME": "simSpeed",   "TYPE": "float", "DEFAULT": 1.10,    "MIN": 0.1,   "MAX": 2.0 },
    { "NAME": "seedRate",   "TYPE": "float", "DEFAULT": 0.70,    "MIN": 0.0,   "MAX": 1.0 },
    { "NAME": "traceLife",  "TYPE": "float", "DEFAULT": 0.9989,  "MIN": 0.990, "MAX": 0.9998 },
    { "NAME": "drift",      "TYPE": "float", "DEFAULT": 1.05,    "MIN": 0.0,   "MAX": 2.0 },
    { "NAME": "motion",     "TYPE": "float", "DEFAULT": 1.0,     "MIN": 0.0,   "MAX": 2.5 },
    { "NAME": "swirl",      "TYPE": "float", "DEFAULT": 1.15,    "MIN": 0.0,   "MAX": 2.0 },
    { "NAME": "warp",       "TYPE": "float", "DEFAULT": 1.10,    "MIN": 0.0,   "MAX": 2.0 },
    { "NAME": "trail",      "TYPE": "float", "DEFAULT": 0.9968,  "MIN": 0.97,  "MAX": 0.9998 },
    { "NAME": "sparkle",    "TYPE": "float", "DEFAULT": 0.82,    "MIN": 0.0,   "MAX": 1.5 },
    { "NAME": "hueShift",   "TYPE": "float", "DEFAULT": 0.11,    "MIN": 0.0,   "MAX": 1.0 },
    { "NAME": "stir",       "TYPE": "float", "DEFAULT": 0.72,    "MIN": 0.0,   "MAX": 1.5 },
    { "NAME": "etch",       "TYPE": "float", "DEFAULT": 0.88,    "MIN": 0.0,   "MAX": 1.5 },
    { "NAME": "flow",       "TYPE": "float", "DEFAULT": 0.68,    "MIN": 0.0,   "MAX": 1.5 },
    { "NAME": "fuse",       "TYPE": "float", "DEFAULT": 0.72,    "MIN": 0.0,   "MAX": 1.0 },
    { "NAME": "deform",     "TYPE": "float", "DEFAULT": 1.10,    "MIN": 0.0,   "MAX": 2.0 },
    { "NAME": "fracture",   "TYPE": "float", "DEFAULT": 0.62,    "MIN": 0.0,   "MAX": 1.5 },
    { "NAME": "filament",   "TYPE": "float", "DEFAULT": 0.92,    "MIN": 0.0,   "MAX": 1.6 },
    { "NAME": "nodeSize",   "TYPE": "float", "DEFAULT": 0.013,   "MIN": 0.005, "MAX": 0.035 },
    { "NAME": "exposure",   "TYPE": "float", "DEFAULT": 1.08,    "MIN": 0.5,   "MAX": 1.8 },
    { "NAME": "horizon",    "TYPE": "float", "DEFAULT": 0.082,   "MIN": 0.035, "MAX": 0.14 },
    { "NAME": "anomaly",    "TYPE": "float", "DEFAULT": 1.0,     "MIN": 0.0,   "MAX": 1.5 }
  ],
  "PASSES": [
    { "TARGET": "chem",  "PERSISTENT": true, "FLOAT": true },
    { "TARGET": "paint", "PERSISTENT": true, "FLOAT": true },
    {}
  ]
}*/

#define TAU 6.28318530718
#define NODES 14

float hash11(float p) {
  return fract(sin(p * 127.1) * 43758.5453123);
}

float hash21(vec2 p) {
  p = fract(p * vec2(123.34, 456.21));
  p += dot(p, p + 45.32);
  return fract(p.x * p.y);
}

vec3 oilPalette(float t) {
  return 0.52 + 0.48 * cos(TAU * (t + hueShift + vec3(0.02, 0.31, 0.61)));
}

vec3 chemPalette(float t) {
  return 0.50 + 0.50 * cos(TAU * (t + vec3(0.08, 0.27, 0.55)));
}

float luminance(vec3 c) {
  return dot(c, vec3(0.299, 0.587, 0.114));
}

vec2 chemistry(vec2 uv) {
  return IMG_NORM_PIXEL(chem, uv).rg;
}

float distSeg(vec2 p, vec2 a, vec2 b) {
  vec2 pa = p - a;
  vec2 ba = b - a;
  float h = clamp(dot(pa, ba) / max(dot(ba, ba), 0.00001), 0.0, 1.0);
  return length(pa - ba * h);
}

float blob(vec2 uv, vec2 center, float size, float aspect) {
  vec2 d = uv - center;
  d.x *= aspect;
  return 1.0 - smoothstep(size * 0.25, size, length(d));
}

vec2 vortex(vec2 p, vec2 center, float spin, float radius) {
  vec2 d = p - center;
  float influence = exp(-dot(d, d) / max(radius * radius, 0.001));
  return vec2(-d.y, d.x) * influence * spin;
}

// This same field advects the liquid and bends the asterism. The geometry is
// therefore downstream of the fluid, reversing the old armature relationship.
vec2 liquidField(vec2 p, float t) {
  vec2 a = vec2(0.29 * cos(t * 0.31), 0.24 * sin(t * 0.43));
  vec2 b = vec2(0.31 * cos(t * 0.27 + 2.8), 0.29 * sin(t * 0.37 + 1.6));
  vec2 c = vec2(0.18 * sin(t * 0.57 + 0.7), 0.33 * cos(t * 0.23 - 0.5));
  vec2 v = vortex(p, a, 2.8, 0.34)
         + vortex(p, b, -2.35, 0.38)
         + vortex(p, c, 1.75, 0.29);
  v += 0.055 * vec2(
    sin(p.y * 8.0 + p.x * 2.0 + t * 0.71),
    cos(p.x * 7.0 - p.y * 3.0 - t * 0.59)
  );
  v += 0.025 * vec2(sin(p.y * 23.0 - t), cos(p.x * 19.0 + t * 0.83));
  return v;
}

vec2 portalA(float t) {
  return vec2(-0.27 + 0.055 * cos(t * 0.23), 0.13 + 0.12 * sin(t * 0.31));
}

vec2 portalB(float t) {
  return vec2(0.25 + 0.065 * sin(t * 0.19), -0.10 + 0.14 * cos(t * 0.27));
}

vec2 quarterTurn(vec2 p) {
  return vec2(-p.y, p.x);
}

vec2 restNode(float i, float t) {
  float angle = i * 2.39996323 + 0.055 * t;
  float radius = 0.16 + 0.31 * (0.5 + 0.5 * sin(i * 1.731 + t * 0.09));
  vec2 p = radius * vec2(cos(angle), sin(angle));
  p += 0.105 * vec2(sin(i * 1.19 - t * 0.13), cos(i * 1.47 + t * 0.11));
  return p;
}

vec2 sculptNode(float i, float t, float aspect) {
  vec2 p = restNode(i, t);
  vec2 uv = vec2(p.x / aspect, p.y) + 0.5;
  vec2 e = vec2(0.013);

float mR = luminance(IMG_NORM_PIXEL(paint, uv + vec2(e.x, 0.0)).rgb);
  float mL = luminance(IMG_NORM_PIXEL(paint, uv - vec2(e.x, 0.0)).rgb);
  float mU = luminance(IMG_NORM_PIXEL(paint, uv + vec2(0.0, e.y)).rgb);
  float mD = luminance(IMG_NORM_PIXEL(paint, uv - vec2(0.0, e.y)).rgb);
  float cR = IMG_NORM_PIXEL(chem, uv + vec2(e.x, 0.0)).b;
  float cL = IMG_NORM_PIXEL(chem, uv - vec2(e.x, 0.0)).b;
  float cU = IMG_NORM_PIXEL(chem, uv + vec2(0.0, e.y)).b;
  float cD = IMG_NORM_PIXEL(chem, uv - vec2(0.0, e.y)).b;

vec2 pressure = vec2(mR - mL, mU - mD) * 1.9;
  pressure += vec2(-(cU - cD), cR - cL) * 0.95;
  pressure /= 1.0 + 3.5 * length(pressure);
  vec2 motionField = liquidField(p, t) + pressure;
  motionField /= 1.0 + 1.8 * length(motionField);
  return p + motionField * (0.42 * deform);
}

vec2 quadPoint(vec2 a, vec2 c, vec2 b, float t) {
  vec2 ac = mix(a, c, t);
  vec2 cb = mix(c, b, t);
  return mix(ac, cb, t);
}

float quadDist(vec2 p, vec2 a, vec2 c, vec2 b) {
  float d = 10.0;
  vec2 last = a;
  for (int k = 1; k <= 5; k++) {
    float s = float(k) / 5.0;
    vec2 here = quadPoint(a, c, b, s);
    d = min(d, distSeg(p, last, here));
    last = here;
  }
  return d;
}

void softAsterism(
  vec2 p, float t, float aspect,
  out float nodeCore, out float nodeHalo,
  out float strandCore, out float strandHalo,
  out float beads, out float ghosts
) {
  nodeCore = 0.0;
  nodeHalo = 0.0;
  strandCore = 0.0;
  strandHalo = 0.0;
  beads = 0.0;
  ghosts = 0.0;

for (int i = 0; i < NODES; i++) {
    float fi = float(i);
    vec2 seed = sculptNode(fi, t, aspect);
    float dn = length(p - seed);
    nodeCore += 1.0 - smoothstep(nodeSize * 0.34, nodeSize, dn);
    nodeHalo += exp(-dn * dn / max(nodeSize * nodeSize * 15.0, 0.00001));

// Each star grows a pair of streamlines by integrating the liquid velocity
    // forward and backward. They are connections authored by flow, not by a
    // geometric nearest-neighbour rule; their destinations keep changing.
    float rnd = hash11(fi * 19.17 + 3.4);
    for (int direction = 0; direction < 2; direction++) {
      float signDir = direction == 0 ? 1.0 : -1.0;
      vec2 last = seed;
      float inversion = 0.0;
      float travel = fract(t * (0.075 + rnd * 0.035) + rnd + float(direction) * 0.37) * 9.0;

for (int k = 0; k < 9; k++) {
        float fk = float(k);
        vec2 velocity = liquidField(last, t + fk * 0.025 * signDir);
        velocity += 0.024 * vec2(
          sin(fi * 2.1 + fk * 0.73 + t * 0.31),
          cos(fi * 1.7 - fk * 0.61 - t * 0.27)
        );
        vec2 tangent = velocity / max(length(velocity), 0.0001);
        vec2 normal = vec2(-tangent.y, tangent.x);
        float stepLength = 0.036 + 0.014 * rnd + 0.004 * sin(fi + fk * 1.3);
        vec2 here = last + signDir * tangent * stepLength;
        here += normal * sin(fi * 1.9 + fk * 1.13 + t * 0.7) * 0.006 * deform;
        vec2 arrival = here;

float fatigue = 0.5 + 0.5 * sin(t * (0.53 + rnd * 0.19) + fi * 1.31 + fk * 0.77);
        float alive = 1.0 - smoothstep(0.54, 0.93, fracture * fatigue);
        float d = distSeg(p, last, arrival);
        float core = 1.0 - smoothstep(0.0010, 0.0040, d);
        float halo = 1.0 - smoothstep(0.003, 0.026, d);
        strandCore += core * alive * (1.0 - 0.35 * inversion);
        strandHalo += halo * alive * (1.0 - 0.20 * inversion);
        ghosts += halo * (1.0 - alive) * (0.10 + 0.30 * fatigue);
        ghosts += (core * 1.35 + halo * 0.22) * inversion * alive * anomaly;

float activeSegment = 1.0 - smoothstep(0.12, 0.55, abs(fk - floor(travel)));
        vec2 beadPos = mix(last, arrival, fract(travel));
        float beadD = length(p - beadPos);
        beads += exp(-beadD * beadD / 0.000045) * activeSegment * alive;

float snap = (1.0 - alive) * smoothstep(0.82, 1.0, fatigue);
        vec2 recoil = normal * (0.008 + 0.012 * fatigue);
        float d1 = length(p - 0.5 * (last + arrival) - recoil);
        float d2 = length(p - 0.5 * (last + arrival) + recoil);
        beads += (exp(-d1 * d1 / 0.000025) + exp(-d2 * d2 / 0.000025)) * snap;

// Crossing an aperture breaks the visible segment at the horizon, then
        // rotates and mirrors its continuation out of the antipodal aperture.
        vec2 pa = portalA(t);
        vec2 pb = portalB(t);
        vec2 localA = arrival - pa;
        vec2 localB = arrival - pb;
        float hitA = step(length(localA), horizon * 0.76) * step(0.5, anomaly);
        float hitB = step(length(localB), horizon * 0.76) * step(0.5, anomaly);
        vec2 exitA = pb + normalize(quarterTurn(localA) + vec2(0.0001))
                         * (horizon * 1.12 + length(localA) * 0.18);
        vec2 exitB = pa + normalize(-quarterTurn(localB) + vec2(0.0001))
                         * (horizon * 1.12 + length(localB) * 0.18);
        here = mix(arrival, exitA, hitA);
        here = mix(here, exitB, hitB);
        inversion = mod(inversion + hitA + hitB, 2.0);
        last = here;
      }
    }
  }
}

void main() {
  vec2 uv = isf_FragNormCoord;
  vec2 px = 1.0 / RENDERSIZE;
  float aspect = RENDERSIZE.x / RENDERSIZE.y;
  vec2 p = uv - 0.5;
  p.x *= aspect;
  float t = TIME * motion;

if (PASSINDEX == 0) {
    vec3 state = IMG_NORM_PIXEL(chem, uv).rgb;
    vec2 c = state.rg;

if (FRAMEINDEX < 2 || dot(c, c) < 0.000001) {
      float cellular = sin(p.x * 26.0) + sin(p.y * 31.0)
                     + sin((p.x - p.y) * 18.0) + cos(length(p) * 39.0);
      float initial = smoothstep(1.45, 2.65, cellular)
                    * (1.0 - smoothstep(0.18, 0.68, length(p)));
      c = mix(vec2(1.0, 0.0), vec2(0.49, 0.31), initial);
    }

vec3 metal = IMG_NORM_PIXEL(paint, uv).rgb;
    float m = luminance(metal);
    float mR = luminance(IMG_NORM_PIXEL(paint, uv + vec2(px.x, 0.0)).rgb);
    float mU = luminance(IMG_NORM_PIXEL(paint, uv + vec2(0.0, px.y)).rgb);
    vec2 metalCurl = vec2(-(mU - m), mR - m);
    vec2 advect = liquidField(p, t) * (0.0028 * drift);
    advect += metalCurl * (0.72 * stir);
    advect.x /= aspect;
    vec2 sampleUV = uv - advect;

vec2 lap = -c;
    lap += 0.20 * chemistry(sampleUV + vec2(px.x, 0.0));
    lap += 0.20 * chemistry(sampleUV - vec2(px.x, 0.0));
    lap += 0.20 * chemistry(sampleUV + vec2(0.0, px.y));
    lap += 0.20 * chemistry(sampleUV - vec2(0.0, px.y));
    lap += 0.05 * chemistry(sampleUV + px);
    lap += 0.05 * chemistry(sampleUV - px);
    lap += 0.05 * chemistry(sampleUV + vec2(px.x, -px.y));
    lap += 0.05 * chemistry(sampleUV + vec2(-px.x, px.y));

float u = c.r;
    float v = c.g;
    float reaction = u * v * v;
    float stepSize = min(TIMEDELTA * 60.0, 1.25) * simSpeed;
    float localFeed = feed * (0.91 + 0.09 * sin(TIME * 1.27));
    u += (0.16 * lap.r - reaction + localFeed * (1.0 - u)) * stepSize;
    v += (0.08 * lap.g + reaction - (kill + localFeed) * v) * stepSize;

// Autonomous chemistry: these moving wounds belong to the liquid system,
    // not to the constellation. The constellation has no seeding authority.
    vec2 oa = vec2(0.5 + 0.27 * cos(t * 0.37), 0.5 + 0.23 * sin(t * 0.51));
    vec2 ob = vec2(0.5 + 0.29 * cos(t * 0.29 + 2.7), 0.5 + 0.26 * sin(t * 0.41 + 1.3));
    vec2 oc = vec2(0.5 + 0.17 * sin(t * 0.67), 0.5 + 0.31 * cos(t * 0.25 - 0.8));
    float fresh = blob(uv, oa, 0.038, aspect);
    fresh += 0.85 * blob(uv, ob, 0.032, aspect);
    fresh += 0.70 * blob(uv, oc, 0.026, aspect);
    fresh = clamp(fresh * seedRate, 0.0, 1.0);
    float metalSeed = smoothstep(0.28, 0.78, m) * stir;
    v = max(v, fresh * 0.43 + metalSeed * 0.22);
    u = mix(u, 0.48, clamp(fresh * 0.72 + metalSeed * 0.24, 0.0, 0.88));

float memory = state.b * 0.73;
    memory += IMG_NORM_PIXEL(chem, uv + vec2(px.x, 0.0)).b * 0.0675;
    memory += IMG_NORM_PIXEL(chem, uv - vec2(px.x, 0.0)).b * 0.0675;
    memory += IMG_NORM_PIXEL(chem, uv + vec2(0.0, px.y)).b * 0.0675;
    memory += IMG_NORM_PIXEL(chem, uv - vec2(0.0, px.y)).b * 0.0675;
    memory *= pow(traceLife, stepSize);
    memory = max(memory, fresh * 0.72);
    memory = max(memory, smoothstep(0.08, 0.32, v) * 0.22);
    memory = max(memory, metalSeed * 0.18);

gl_FragColor = vec4(clamp(u, 0.0, 1.0), clamp(v, 0.0, 1.0), clamp(memory, 0.0, 1.0), 1.0);

} else if (PASSINDEX == 1) {
    float frameStep = min(TIMEDELTA * 60.0, 2.0);
    vec2 vel = liquidField(p, t);

float v0 = IMG_NORM_PIXEL(chem, uv).g;
    float vR = IMG_NORM_PIXEL(chem, uv + vec2(px.x, 0.0)).g;
    float vU = IMG_NORM_PIXEL(chem, uv + vec2(0.0, px.y)).g;
    vec2 chemCurl = vec2(-(vU - v0), vR - v0);
    vel += chemCurl * (30.0 * flow);
    vel *= swirl;
    vel.x /= aspect;

vec2 back = uv - vel * (0.015 * frameStep);
    vec3 old = IMG_NORM_PIXEL(paint, back).rgb * 0.64;
    old += IMG_NORM_PIXEL(paint, back + vec2(px.x, 0.0)).rgb * 0.085;
    old += IMG_NORM_PIXEL(paint, back - vec2(px.x, 0.0)).rgb * 0.085;
    old += IMG_NORM_PIXEL(paint, back + vec2(0.0, px.y)).rgb * 0.085;
    old += IMG_NORM_PIXEL(paint, back - vec2(0.0, px.y)).rgb * 0.085;
    old *= pow(trail, frameStep);

vec2 a = vec2(0.29 * cos(t * 0.31), 0.24 * sin(t * 0.43));
    vec2 b = vec2(0.31 * cos(t * 0.27 + 2.8), 0.29 * sin(t * 0.37 + 1.6));
    vec2 cC = vec2(0.18 * sin(t * 0.57 + 0.7), 0.33 * cos(t * 0.23 - 0.5));
    float da = length(p - a);
    float db = length(p - b);
    float dc = length(p - cC);
    float sourceA = 1.0 - smoothstep(0.012, 0.065, da);
    float sourceB = 1.0 - smoothstep(0.010, 0.054, db);
    float sourceC = 1.0 - smoothstep(0.008, 0.043, dc);
    float bridge = 1.0 - smoothstep(0.012, 0.052, distSeg(p, a, b));
    bridge *= smoothstep(0.0, 0.22, min(da, db));

vec3 fresh = oilPalette(t * 0.025 + 0.08) * sourceA;
    fresh += oilPalette(t * 0.025 + 0.51) * sourceB;
    fresh += oilPalette(t * 0.025 + 0.83) * sourceC;
    fresh += mix(vec3(0.02, 0.62, 0.82), vec3(0.95, 0.18, 0.42),
                 0.5 + 0.5 * sin(t * 0.4)) * bridge * 0.18;

float chm = IMG_NORM_PIXEL(chem, uv).b;
    float chemicalBody = smoothstep(0.025, 0.58, chm);
    float reactionFront = smoothstep(0.015, 0.24, v0);
    fresh += chemPalette(v0 * 2.7 + chm * 0.42) * chemicalBody * (0.44 * etch);
    fresh += oilPalette(chm * 0.7 + 0.28) * reactionFront * 0.12;

float boundary = smoothstep(0.0, 0.025, uv.x)
                   * smoothstep(0.0, 0.025, 1.0 - uv.x)
                   * smoothstep(0.0, 0.025, uv.y)
                   * smoothstep(0.0, 0.025, 1.0 - uv.y);
    vec3 next = max(old, fresh * 0.47) * boundary;
    vec3 hot = max(next - vec3(0.72), vec3(0.0));
    next = min(next, vec3(0.72)) + hot / (1.0 + hot);
    gl_FragColor = vec4(clamp(next, 0.0, 1.35), 1.0);

} else {
    vec3 c0 = IMG_NORM_PIXEL(paint, uv).rgb;
    vec3 cR = IMG_NORM_PIXEL(paint, uv + vec2(px.x * 1.8, 0.0)).rgb;
    vec3 cL = IMG_NORM_PIXEL(paint, uv - vec2(px.x * 1.8, 0.0)).rgb;
    vec3 cU = IMG_NORM_PIXEL(paint, uv + vec2(0.0, px.y * 1.8)).rgb;
    vec3 cD = IMG_NORM_PIXEL(paint, uv - vec2(0.0, px.y * 1.8)).rgb;
    float lum = luminance(c0);
    vec2 grad = vec2(luminance(cR) - luminance(cL), luminance(cU) - luminance(cD));
    float rim = clamp(length(grad) * 38.0, 0.0, 1.0);
    float body = smoothstep(0.018, 0.46, lum);
    float reflection = 0.5 + 0.5 * sin(17.0 * uv.x - 11.0 * uv.y + t * 0.48 + lum * 9.0);
    float glint = pow(max(reflection * rim, 0.0), 3.0) * sparkle;

vec3 dispersed = vec3(cR.r, c0.g, cL.b);
    vec3 liquid = mix(c0, dispersed, 0.52);
    liquid *= 0.20 + 1.42 * lum;
    liquid += oilPalette(0.13 + lum * 0.34) * rim * (0.42 + 0.36 * sparkle);
    liquid += vec3(0.90, 0.96, 1.0) * glint;

vec3 chm = IMG_NORM_PIXEL(chem, uv).rgb;
    float ink = smoothstep(0.018, 0.30, chm.g);
    float memory = smoothstep(0.025, 0.62, chm.b);
    float gx = length(IMG_NORM_PIXEL(chem, uv + vec2(px.x, 0.0)).rg - chm.rg);
    float gy = length(IMG_NORM_PIXEL(chem, uv + vec2(0.0, px.y)).rg - chm.rg);
    float chemEdge = clamp((gx + gy) * 20.0, 0.0, 1.0);
    vec3 spectral = chemPalette(chm.g * 2.6 + chm.b * 0.35);
    spectral *= memory * (0.24 + 0.42 * fuse) + ink * 0.08;
    spectral += oilPalette(chm.b * 0.48 + 0.66) * chemEdge * 0.32;

vec3 bg = mix(vec3(0.002, 0.006, 0.018), vec3(0.012, 0.004, 0.020), uv.y);
    float grain = hash21(floor(gl_FragCoord.xy));
    float star = smoothstep(0.9965, 1.0, grain);
    bg += star * vec3(0.35, 0.58, 0.82) * (0.25 + 0.45 * sin(t * 1.7 + grain * 40.0));

vec3 field = bg * (1.0 - body * 0.62) + liquid + spectral;
    field *= 0.72 + 0.28 * smoothstep(0.0, 0.22, body + memory);

// Each dark lens contains a live, quarter-turned view through the opposite
    // fluid region. Green and fuchsia are deliberately alien to the parent.
    vec2 pa = portalA(t);
    vec2 pb = portalB(t);
    vec2 la = p - pa;
    vec2 lb = p - pb;
    float da = length(la);
    float db = length(lb);
    float holeA = 1.0 - smoothstep(horizon * 0.72, horizon * 0.94, da);
    float holeB = 1.0 - smoothstep(horizon * 0.72, horizon * 0.94, db);
    float lensA = 1.0 - smoothstep(horizon, horizon * 1.75, da);
    float lensB = 1.0 - smoothstep(horizon, horizon * 1.75, db);
    float ringA = 1.0 - smoothstep(0.002, 0.010, abs(da - horizon));
    float ringB = 1.0 - smoothstep(0.002, 0.010, abs(db - horizon));
    vec2 throughA = pb + quarterTurn(la) * 0.82;
    vec2 throughB = pa - quarterTurn(lb) * 0.82;
    vec2 uvA = vec2(throughA.x / aspect, throughA.y) + 0.5;
    vec2 uvB = vec2(throughB.x / aspect, throughB.y) + 0.5;
    vec3 visionA = IMG_NORM_PIXEL(paint, uvA).gbr;
    vec3 visionB = IMG_NORM_PIXEL(paint, uvB).brg;
    visionA = visionA * 1.25 + vec3(0.02, 0.36, 0.10);
    visionB = visionB * 1.25 + vec3(0.40, 0.01, 0.19);
    float portalMix = clamp(anomaly, 0.0, 1.0);
    field = mix(field, visionA, holeA * portalMix * 0.88);
    field = mix(field, visionB, holeB * portalMix * 0.88);
    field *= 1.0 - (holeA + holeB) * (0.20 + 0.20 * portalMix);
    field += vec3(0.01, 0.32, 0.12) * lensA * (1.0 - holeA) * anomaly * 0.23;
    field += vec3(0.40, 0.01, 0.22) * lensB * (1.0 - holeB) * anomaly * 0.23;

float nCore, nHalo, sCore, sHalo, beadMask, ghostMask;
    softAsterism(p, t, aspect, nCore, nHalo, sCore, sHalo, beadMask, ghostMask);
    float localEnergy = clamp(lum * 1.7 + memory * 0.55 + rim * 0.35, 0.0, 1.0);
    vec3 coolWire = mix(vec3(0.05, 0.78, 1.0), vec3(0.45, 0.08, 0.86), localEnergy);
    vec3 hotWire = mix(vec3(0.30, 0.90, 1.0), vec3(1.0, 0.44, 0.12), localEnergy * localEnergy);

// Hairline cores sit inside broad colored interference halos. Failed links
    // remain as dim afterimages, making reconnection visible instead of abrupt.
    field += coolWire * sHalo * filament * (0.10 + 0.28 * localEnergy);
    vec3 phantom = mix(vec3(0.10, 1.0, 0.32), vec3(1.0, 0.03, 0.58),
                       0.5 + 0.5 * sin(p.x * 9.0 - p.y * 7.0 + t));
    field += phantom * ghostMask * (0.16 * fracture + 0.36 * anomaly);
    field += hotWire * sCore * filament * (0.42 + 0.42 * localEnergy);
    field += vec3(0.92, 0.98, 1.0) * sCore * filament * 0.20;
    field += coolWire * nHalo * (0.18 + 0.25 * localEnergy);
    field += hotWire * nCore * 0.72;
    field += vec3(1.0, 0.98, 0.91) * (nCore * nCore + beadMask * 0.92);
    field += oilPalette(0.76 + t * 0.02) * beadMask * sparkle * 0.48;
    field += vec3(0.16, 1.0, 0.42) * ringA * anomaly * (0.48 + 0.35 * sparkle);
    field += vec3(1.0, 0.06, 0.48) * ringB * anomaly * (0.48 + 0.35 * sparkle);
    field += vec3(0.92, 1.0, 0.95) * (ringA + ringB) * 0.20;

// Fluid lenses eclipse the node centers; stars feel embedded in the liquid,
    // not pasted over it.
    field *= 1.0 - clamp(nCore * 0.18 * body, 0.0, 0.32);
    field *= exposure;
    field *= 1.0 - 0.22 * dot(p, p);
    field = field / (1.0 + 0.46 * field);
    field = pow(max(field, 0.0), vec3(0.88));
    gl_FragColor = vec4(field, 1.0);
  }
}

Antipodal Nervous System

#obfix37n

⑂ fork it { } json

Antipodal Nervous System: Soft Asterism develops a pair of moving event horizons. Fluid-authored constellations fall into one aperture, re-emerge mirrored from the other, and continue as reversed-color phantom nerves while each horizon shows a live image of its antipode.

feedbackfluidconstellationwormholereaction-diffusionspectral

by ufffduser_uploadmade with glslopCC0-1.0credit: glslop agent (Codex), mutating Soft Asterismactivecreated 2026-07-14 22:59Z133 views0 forks23 paramsmultipass ×3

export clip · render a video in your browser

Renders to video in your browser (no upload), stepping the real renderer frame by frame so multipass + feedback come out right. motion auto-animates the shader's own knobs — each export rolls a fresh take (🎲 re-roll, 🔒 to pin one you like). GIF is slower with a tighter length cap; MP4/WebM are faster. Some devices record in real time (noted below if so) — keep the tab visible.

format length max 300 sec at this fps start frame motion fps size quality

caps: ≤1920 per side, ≤60fps, ≤18000 frames (GIF ≤300)

embed · drop this shader into any page

glslop backlink play/pause + fullscreen size

<iframe src="https://glslop.com/embed/obfix37n" width="512" height="512" style="border:0;max-width:100%;aspect-ratio:1/1" loading="lazy" allowfullscreen title="Antipodal Nervous System — a shader on glslop"></iframe>

preview ↗

Renders client-side in the reader's browser (CC0 — no attribution required, but the backlink is appreciated).