Rocaille Shader Skill

Generate organic, swirling light effects through progressive domain warping - a technique that creates increasingly complex patterns by iteratively displacing coordinates using sinusoidal functions.

Core Technique

The Rocaille effect builds complexity through repeated application of:

v += sin(v.yx + t) / amplitude;

Where:

• v is a 2D coordinate vector
• v.yx swaps x/y components creating characteristic swirl
• t is time for animation
• amplitude controls warp intensity (1.0 = strong, 4.0 = subtle)
• Each iteration adds more organic complexity

Quick Reference

Usage

To generate a shader, specify:

1. Warp count (1-15): Number of displacement iterations
2. Color mode: basic, rainbow, monochrome, neon, or custom RGB
3. Output format: shadertoy, threejs, webgl, p5js

Generate Custom Shader

Run the generator script:

python3 scripts/rocaille_generator.py --warps 5 --color rainbow --format shadertoy

Options:

• --warps N - Number of warp iterations (default: 5)
• --color MODE - Color mode: basic, rainbow, monochrome, neon (default: rainbow)
• --format FMT - Output format: shadertoy, threejs, webgl, p5js, all (default: shadertoy)
• --amplitude N - Warp intensity divisor (default: 2.0)
• --speed N - Animation speed multiplier (default: 1.0)
• --demo - Generate interactive HTML demo page

Asset Templates

Pre-built templates available in assets/templates/:

Implementation Patterns

Minimal Shadertoy

void mainImage(out vec4 fragColor, in vec2 fragCoord) {
    vec2 uv = (fragCoord - 0.5 * iResolution.xy) / iResolution.y;
    vec2 v = uv;

    for(int i = 0; i < 5; i++) {
        v += sin(v.yx + iTime) / 2.0;
    }

    float d = 1.0 / length(v);
    fragColor = vec4(vec3(d * 0.1), 1.0);
}

Three.js Integration

const material = new THREE.ShaderMaterial({
    uniforms: {
        uTime: { value: 0 },
        uWarpCount: { value: 5 },
        uAmplitude: { value: 2.0 }
    },
    vertexShader: vertexCode,
    fragmentShader: fragmentCode
});

// In animation loop
material.uniforms.uTime.value = performance.now() / 1000;

Customization

Base Shape Variations

Replace 1.0 / length(v) with:

• length(v) - Inverted (dark center)
• sin(length(v) * 10.0) - Ripple rings
• abs(v.x) + abs(v.y) - Diamond shape
• max(abs(v.x), abs(v.y)) - Square shape

Color Mapping

// Rainbow based on angle
vec3 color = 0.5 + 0.5 * cos(atan(v.y, v.x) + vec3(0, 2, 4));

// Neon glow
vec3 color = vec3(d * 0.2, d * 0.05, d * 0.3);

// Temperature gradient
vec3 color = mix(vec3(0.1, 0.2, 0.8), vec3(1.0, 0.3, 0.1), d);

Reference Documentation

For deeper understanding:

• references/rocaille-complete.md - Full 8-step shader breakdown
• references/domain-warping.md - Theory from Inigo Quilez
• references/glsl-patterns.md - Common GLSL patterns used

Combining Effects

Layer with other techniques:

• Bloom: Apply gaussian blur to bright areas
• Grain: Add fract(sin(dot(uv, vec2(12.9898, 78.233))) * 43758.5453)
• Vignette: Multiply by 1.0 - length(uv) * 0.5
• Chromatic aberration: Sample RGB at slightly offset UVs