radiance: shaded coral body + deeper right rim, red mass weighted to lower latitudes, bigger flakes, crisper haloed glints and corona

src/scripts/orb.js

@@ -104,7 +104,12 @@ float layerR(uint idx) {
 float density(vec3 dir, float t) {
   vec3 w = dir * 1.6 + vec3(0.0, t * 0.05, t * 0.035);
   float n = fbm(w + 1.6 * fbm(w * 0.8 + 3.1));
-  return clamp(1.0 - abs(n - 0.48) * 4.2, 0.0, 1.0);
+  float ridge = 1.0 - abs(n - 0.48) * 4.2;
+  // plus broad swells, so red gathers in big masses and not only thin ribbons
+  float swell = fbm(dir * 0.9 + vec3(0.0, t * 0.03, 7.3));
+  float d = clamp(max(ridge, (swell - 0.4) * 3.2), 0.0, 1.0);
+  // the red gathers toward the middle latitudes (the lower part of what the camera sees), thinning over the crown
+  return d * mix(0.6, 1.0, 1.0 - smoothstep(0.15, 0.85, dir.y));
 }
 // where a particle is reborn: best of four candidates against the density field
 vec3 spawnDir(uint idx, float epoch, float t) {
@@ -146,7 +151,7 @@ P corona(uint idx) {
   float n = fbm(vec3(cd * 4.2, t * 0.10));
   float up = smoothstep(-0.75, 0.9, cd.y);
   float spike = pow(n, 1.6) * 1.6;
-  float reach = pow(o.r.x, 1.5) * (0.05 + 0.4 * spike) * (0.3 + 0.7 * up);
+  float reach = pow(o.r.x, 1.3) * (0.07 + 0.5 * spike) * (0.3 + 0.7 * up);
   reach *= 0.88 + 0.12 * sin(t * 0.7 + o.r.w * 20.0);
   reach += 0.012 * sin(t * 0.9 + o.r.z * 30.0);
   o.n = n;
@@ -430,7 +435,7 @@ void main() {
 
   if (idx < uInner) {
     vec4 r = vec4(h01(idx * 8u), h01(idx * 8u + 1u), h01(idx * 8u + 2u), h01(idx * 8u + 3u));
-    float spark = step(0.88, h01(idx * 8u + 6u));
+    float spark = step(0.86, h01(idx * 8u + 6u));
     float rt = layerR(idx);
     float lt = lifeT(idx, t);
     vec3 pos = s0.xyz;
@@ -442,12 +447,12 @@ void main() {
     vp = bp.xy * persp;
 
     float n = density(normalize(pos + vec3(1e-5)), t);
-    vec3 warm = mix(vec3(0.94, 0.27, 0.20), vec3(1.0, 0.52, 0.32), r.w);
-    warm = mix(warm, vec3(1.0, 0.72, 0.42), smoothstep(0.1, 0.45, 1.0 - n) * 0.8);
-    col = vec4(mix(warm, vec3(1.0, 0.97, 0.84), spark), mix(0.95, 0.95, spark));
-    size = mix(1.15 + r.y * 1.2 + n * 0.8, 2.0 + r.w * 2.0, spark);
+    vec3 warm = mix(vec3(0.88, 0.17, 0.15), vec3(1.0, 0.45, 0.28), r.w * r.w);
+    warm = mix(warm, vec3(1.0, 0.70, 0.40), smoothstep(0.25, 0.7, 1.0 - n) * 0.85);
+    col = vec4(mix(warm, vec3(1.0, 0.99, 0.92), spark), 0.95);
+    size = mix(1.5 + r.y * 1.5 + n * 1.3, 2.8 + r.w * 2.4, spark);
     float tw = 0.5 + 0.5 * sin(t * (1.2 + r.x * 2.5) + r.w * 40.0);
-    col.a *= mix(1.0, tw, spark);
+    col.a *= mix(1.0, mix(0.4, 1.0, tw), spark);
     vGlow = spark;
     // the far side reads dimmer through the glass, and so do particles hanging deep in the volume
     // (it also thins the crowd that edge-on particles would form along the limb)
@@ -465,10 +470,13 @@ void main() {
     float stir = clamp(length(disp) * 1.6 + length(s1.xy) * 0.35, 0.0, 1.5);
     vp = p.xy + disp;
     float tw = 0.5 + 0.5 * sin(t * (1.0 + p.r.y * 3.0) + p.r.z * 60.0);
-    col = vec4(1.0, 0.97, 0.86, (0.3 + 0.7 * p.fade) * (0.35 + 0.65 * smoothstep(0.2, 0.75, p.n)));
-    col.a *= mix(0.5, 1.0, tw);
-    size = 1.0 + p.r.y * p.r.y * 2.6 * (0.3 + p.fade);
-    vGlow = 0.5;
+    col = vec4(1.0, 0.98, 0.88, (0.45 + 0.55 * p.fade) * (0.5 + 0.5 * smoothstep(0.2, 0.75, p.n)));
+    col.a *= mix(0.55, 1.0, tw);
+    // a minority of sparks are bright, haloed points; the rest stay faint dust
+    float lead = step(0.7, p.r.x);
+    col.a *= mix(0.7, 1.0, lead);
+    size = (1.0 + p.r.y * p.r.y * 2.8 * (0.3 + p.fade)) * mix(0.9, 1.5, lead);
+    vGlow = mix(0.4, 1.0, lead);
     // sparks that get knocked off the limb flare, then fade out while they are away from home
     float away = smoothstep(0.03, 0.5, length(disp));
     col.a *= 1.0 - 0.8 * away;
@@ -491,7 +499,7 @@ void main() {
   vec2 c = gl_PointCoord - 0.5;
   float r = length(c);
   float core = smoothstep(0.5, 0.18, r);
-  float halo = vGlow * smoothstep(0.5, 0.0, r) * 0.35;
+  float halo = vGlow * smoothstep(0.5, 0.0, r) * 0.55;
   float a = vColor.a * clamp(core + halo, 0.0, 1.0);
   if (a < 0.01) discard;
   o = vec4(vColor.rgb * a, a);
@@ -575,17 +583,19 @@ void main() {
   float z = sqrt(max(0.0, 1.0 - r * r));
   vec3 n = vec3(d.x, -d.y, z);
 
-  // glassy body: lighter top-left, deeper orange bottom-right
-  vec3 top = vec3(1.0, 0.77, 0.56);
-  vec3 bot = vec3(1.0, 0.56, 0.42);
-  float lit = clamp(0.5 + 0.5 * dot(normalize(n), normalize(vec3(-0.45, 0.6, 0.65))), 0.0, 1.0);
+  // shaded body: peach at the top-left deepening to saturated coral toward the bottom and right
+  vec3 top = vec3(1.0, 0.80, 0.58);
+  vec3 bot = vec3(1.0, 0.45, 0.33);
+  float lit = clamp(0.5 + 0.5 * dot(normalize(n), normalize(vec3(-0.5, 0.55, 0.65))), 0.0, 1.0);
+  lit = pow(lit, 1.6);
   vec3 body = mix(bot, top, lit);
+  body = mix(body, vec3(1.0, 0.33, 0.28), smoothstep(-0.3, 0.25, d.y) * 0.45);    // the lower visible band runs red
 
-  // fresnel rim, pale pink-white
+  // fresnel rim: pale on the left, deeper pink on the right
   float fres = pow(1.0 - z, 1.8);
-  vec3 rim = vec3(1.0, 0.85, 0.83);
+  vec3 rim = mix(vec3(1.0, 0.86, 0.84), vec3(1.0, 0.52, 0.55), smoothstep(-0.2, 0.8, d.x));
   vec3 col = mix(body, rim, clamp(fres * 1.15, 0.0, 1.0));
-  float a = mix(0.58, 0.97, fres);
+  float a = mix(0.72, 0.97, fres);
 
   // crisp bright edge line
   float ring = smoothstep(0.955, 0.985, r) * (1.0 - smoothstep(0.985, 1.004, r));