Bright areas seed a reaction-diffusion growth that creeps outward frame after frame.
GLSL fragment shader
The effect's own code. The uniforms and helpers above it — uTex, uFeedback, the depth proxy, the frame ring, depthAt(), timeAt() — are the same header every Ether-MOSH shader opens with, and are documented once on the registry rather than reprinted on all 143 pages.
void main(){ vec2 px = 1.0/uResolution; vec4 cur = texture2D(uTex, vUv); // Laplacian of the history = diffusion term. vec3 c = texture2D(uFeedback, vUv).rgb; vec3 lap = texture2D(uFeedback, vUv + vec2(px.x,0.0)).rgb + texture2D(uFeedback, vUv - vec2(px.x,0.0)).rgb + texture2D(uFeedback, vUv + vec2(0.0,px.y)).rgb + texture2D(uFeedback, vUv - vec2(0.0,px.y)).rgb - 4.0 * c; float seed = max(0.0, dot(cur.rgb, vec3(0.299,0.587,0.114)) - 0.55); vec3 grown = c + lap * uGrowth * 0.28 + seed * 0.25; grown *= mix(0.90, 0.985, uDecay); gl_FragColor = vec4(max(cur.rgb * 0.85, grown), cur.a); }