name: p5js

description: "Production pipeline for interactive and generative visual art using p5.js. Creates browser-based sketches, generative art, data visualizations, interactive experiences, 3D scenes, audio-reactive visuals, and motion graphics — exported as HTML, PNG, GIF, MP4, or SVG. Covers: 2D/3D rendering, noise and particle systems, flow fields, shaders (GLSL), pixel manipulation, kinetic typography, WebGL scenes, audio analysis, mouse/keyboard interaction, and headless high-res export. Use when users request: p5.js sketches, creative coding, generative art, interactive visualizations, canvas animations, browser-based visual art, data viz, shader effects, or any p5.js project."

version: 1.0.0

metadata:

hermes:

tags: [creative-coding, generative-art, p5js, canvas, interactive, visualization, webgl, shaders, animation]

related_skills: [ascii-video, manim-video, excalidraw]

p5.js Production Pipeline

Creative Standard

This is visual art rendered in the browser. The canvas is the medium; the algorithm is the brush.

Before writing a single line of code, articulate the creative concept. What does this piece communicate? What makes the viewer stop scrolling? What separates this from a code tutorial example? The user's prompt is a starting point — interpret it with creative ambition.

First-render excellence is non-negotiable. The output must be visually striking on first load. If it looks like a p5.js tutorial exercise, a default configuration, or "AI-generated creative coding," it is wrong. Rethink before shipping.

Go beyond the reference vocabulary. The noise functions, particle systems, color palettes, and shader effects in the references are a starting vocabulary. For every project, combine, layer, and invent. The catalog is a palette of paints — you write the painting.

Be proactively creative. If the user asks for "a particle system," deliver a particle system with emergent flocking behavior, trailing ghost echoes, palette-shifted depth fog, and a background noise field that breathes. Include at least one visual detail the user didn't ask for but will appreciate.

Dense, layered, considered. Every frame should reward viewing. Never flat white backgrounds. Always compositional hierarchy. Always intentional color. Always micro-detail that only appears on close inspection.

Cohesive aesthetic over feature count. All elements must serve a unified visual language — shared color temperature, consistent stroke weight vocabulary, harmonious motion speeds. A sketch with ten unrelated effects is worse than one with three that belong together.

Modes

Stack

Single self-contained HTML file per project. No build step required.

Version Note

p5.js 1.x (1.11.3) is the default — stable, well-documented, broadest library compatibility. Use this unless a project requires 2.x features.

p5.js 2.x (2.2+) adds: async setup() replacing preload(), OKLCH/OKLAB color modes, splineVertex(), shader .modify() API, variable fonts, textToContours(), pointer events. Required for p5.brush. See references/core-api.md § p5.js 2.0.

Pipeline

Every project follows the same 6-stage path:

`

CONCEPT → DESIGN → CODE → PREVIEW → EXPORT → VERIFY

`

1. CONCEPT — Articulate the creative vision: mood, color world, motion vocabulary, what makes this unique

2. DESIGN — Choose mode, canvas size, interaction model, color system, export format. Map concept to technical decisions

3. CODE — Write single HTML file with inline p5.js. Structure: globals → preload() → setup() → draw() → helpers → classes → event handlers

4. PREVIEW — Open in browser, verify visual quality. Test at target resolution. Check performance

5. EXPORT — Capture output: saveCanvas() for PNG, saveGif() for GIF, saveFrames() + ffmpeg for MP4, Puppeteer for headless batch

6. VERIFY — Does the output match the concept? Is it visually striking at the intended display size? Would you frame it?

Creative Direction

Aesthetic Dimensions

Per-Project Variation Rules

Never use default configurations. For every project:

• - Custom color palette — never raw fill(255, 0, 0). Always a designed palette with 3-7 colors
• - Custom stroke weight vocabulary — thin accents (0.5), medium structure (1-2), bold emphasis (3-5)
• - Background treatment — never plain background(0) or background(255). Always textured, gradient, or layered
• - Motion variety — different speeds for different elements. Primary at 1x, secondary at 0.3x, ambient at 0.1x
• - At least one invented element — a custom particle behavior, a novel noise application, a unique interaction response

Project-Specific Invention

For every project, invent at least one of:

• - A custom color palette matching the mood (not a preset)
• - A novel noise field combination (e.g., curl noise + domain warp + feedback)
• - A unique particle behavior (custom forces, custom trails, custom spawning)
• - An interaction mechanic the user didn't request but that elevates the piece
• - A compositional technique that creates visual hierarchy

Parameter Design Philosophy

Parameters should emerge from the algorithm, not from a generic menu. Ask: "What properties of this system should be tunable?"

Good parameters expose the algorithm's character:

• - Quantities — how many particles, branches, cells (controls density)
• - Scales — noise frequency, element size, spacing (controls texture)
• - Rates — speed, growth rate, decay (controls energy)
• - Thresholds — when does behavior change? (controls drama)
• - Ratios — proportions, balance between forces (controls harmony)

Bad parameters are generic controls unrelated to the algorithm:

• - "color1", "color2", "size" — meaningless without context
• - Toggle switches for unrelated effects
• - Parameters that only change cosmetics, not behavior

Every parameter should change how the algorithm thinks, not just how it looks. A "turbulence" parameter that changes noise octaves is good. A "particle size" slider that only changes ellipse() radius is shallow.

Workflow

Step 1: Creative Vision

Before any code, articulate:

• - Mood / atmosphere: What should the viewer feel? Contemplative? Energized? Unsettled? Playful?
• - Visual story: What happens over time (or on interaction)? Build? Decay? Transform? Oscillate?
• - Color world: Warm/cool? Monochrome? Complementary? What's the dominant hue? The accent?
• - Shape language: Organic curves? Sharp geometry? Dots? Lines? Mixed?
• - Motion vocabulary: Slow drift? Explosive burst? Breathing pulse? Mechanical precision?
• - What makes THIS different: What is the one thing that makes this sketch unique?

Map the user's prompt to aesthetic choices. "Relaxing generative background" demands different everything from "glitch data visualization."

Step 2: Technical Design

• - Mode — which of the 7 modes from the table above
• - Canvas size — landscape 1920x1080, portrait 1080x1920, square 1080x1080, or responsive windowWidth/windowHeight
• - Renderer — P2D (default) or WEBGL (for 3D, shaders, advanced blend modes)
• - Frame rate — 60fps (interactive), 30fps (ambient animation), or noLoop() (static generative)
• - Export target — browser display, PNG still, GIF loop, MP4 video, SVG vector
• - Interaction model — passive (no input), mouse-driven, keyboard-driven, audio-reactive, scroll-driven
• - Viewer UI — for interactive generative art, start from templates/viewer.html which provides seed navigation, parameter sliders, and download. For simple sketches or video export, use bare HTML

Step 3: Code the Sketch

For interactive generative art (seed exploration, parameter tuning): start from templates/viewer.html. Read the template first, keep the fixed sections (seed nav, actions), replace the algorithm and parameter controls. This gives the user seed prev/next/random/jump, parameter sliders with live update, and PNG download — all wired up.

For animations, video export, or simple sketches: use bare HTML:

Single HTML file. Structure:

`html

`

Key implementation patterns:

• - Seeded randomness: Always randomSeed() + noiseSeed() for reproducibility
• - Color mode: Use colorMode(HSB, 360, 100, 100, 100) for intuitive color control
• - State separation: CONFIG for parameters, PALETTE for colors, globals for mutable state
• - Class-based entities: Particles, agents, shapes as classes with update() + display() methods
• - Offscreen buffers: createGraphics() for layered composition, trails, masks

Step 4: Preview & Iterate

• - Open HTML file directly in browser — no server needed for basic sketches
• - For loadImage()/loadFont() from local files: use scripts/serve.sh or python3 -m http.server
• - Chrome DevTools Performance tab to verify 60fps
• - Test at target export resolution, not just the window size
• - Adjust parameters until the visual matches the concept from Step 1

Step 5: Export

Step 6: Quality Verification

Critical Implementation Notes

Performance — Disable FES First

The Friendly Error System (FES) adds up to 10x overhead. Disable it in every production sketch:

`javascript

p5.disableFriendlyErrors = true; // BEFORE setup()

function setup() {

pixelDensity(1); // prevent 2x-4x overdraw on retina

createCanvas(1920, 1080);

}

`

In hot loops (particles, pixel ops), use Math.* instead of p5 wrappers — measurably faster:

`javascript

// In draw() or update() hot paths:

let a = Math.sin(t); // not sin(t)

let r = Math.sqrt(dxdx+dydy); // not dist() — or better: skip sqrt, compare magSq

let v = Math.random(); // not random() — when seed not needed

let m = Math.min(a, b); // not min(a, b)

`

Never console.log() inside draw(). Never manipulate DOM in draw(). See references/troubleshooting.md § Performance.

Seeded Randomness — Always

Every generative sketch must be reproducible. Same seed, same output.

`javascript

function setup() {

randomSeed(CONFIG.seed);

noiseSeed(CONFIG.seed);

// All random() and noise() calls now deterministic

}

`

Never use Math.random() for generative content — only for performance-critical non-visual code. Always random() for visual elements. If you need a random seed: CONFIG.seed = floor(random(99999)).

Generative Art Platform Support (fxhash / Art Blocks)

For generative art platforms, replace p5's PRNG with the platform's deterministic random:

`javascript

// fxhash convention

const SEED = $fx.hash; // unique per mint

const rng = $fx.rand; // deterministic PRNG

$fx.features({ palette: 'warm', complexity: 'high' });

// In setup():

randomSeed(SEED); // for p5's noise()

noiseSeed(SEED);

// Replace random() with rng() for platform determinism

let x = rng() * width; // instead of random(width)

`

See references/export-pipeline.md § Platform Export.

Color Mode — Use HSB

HSB (Hue, Saturation, Brightness) is dramatically easier to work with than RGB for generative art:

`javascript

colorMode(HSB, 360, 100, 100, 100);

// Now: fill(hue, sat, bri, alpha)

// Rotate hue: fill((baseHue + offset) % 360, 80, 90)

// Desaturate: fill(hue, sat * 0.3, bri)

// Darken: fill(hue, sat, bri * 0.5)

`

Never hardcode raw RGB values. Define a palette object, derive variations procedurally. See references/color-systems.md.

Noise — Multi-Octave, Not Raw

Raw noise(x, y) looks like smooth blobs. Layer octaves for natural texture:

`javascript

function fbm(x, y, octaves = 4) {

let val = 0, amp = 1, freq = 1, sum = 0;

for (let i = 0; i < octaves; i++) {

val += noise(x freq, y freq) * amp;

sum += amp;

amp *= 0.5;

freq *= 2;

}

return val / sum;

}

`

For flowing organic forms, use domain warping: feed noise output back as noise input coordinates. See references/visual-effects.md.

createGraphics() for Layers — Not Optional

Flat single-pass rendering looks flat. Use offscreen buffers for composition:

`javascript

let bgLayer, fgLayer, trailLayer;

function setup() {

createCanvas(1920, 1080);

bgLayer = createGraphics(width, height);

fgLayer = createGraphics(width, height);

trailLayer = createGraphics(width, height);

}

function draw() {

renderBackground(bgLayer);

renderTrails(trailLayer); // persistent, fading

renderForeground(fgLayer); // cleared each frame

image(bgLayer, 0, 0);

image(trailLayer, 0, 0);

image(fgLayer, 0, 0);

}

`

Performance — Vectorize Where Possible

p5.js draw calls are expensive. For thousands of particles:

`javascript

// SLOW: individual shapes

for (let p of particles) {

ellipse(p.x, p.y, p.size);

}

// FAST: single shape with beginShape()

beginShape(POINTS);

for (let p of particles) {

vertex(p.x, p.y);

}

endShape();

// FASTEST: pixel buffer for massive counts

loadPixels();

for (let p of particles) {

let idx = 4 (floor(p.y) width + floor(p.x));

pixels[idx] = r; pixels[idx+1] = g; pixels[idx+2] = b; pixels[idx+3] = 255;

}

updatePixels();

`

See references/troubleshooting.md § Performance.

Instance Mode for Multiple Sketches

Global mode pollutes window. For production, use instance mode:

`javascript

const sketch = (p) => {

p.setup = function() {

p.createCanvas(800, 800);

};

p.draw = function() {

p.background(0);

p.ellipse(p.mouseX, p.mouseY, 50);

};

};

new p5(sketch, 'canvas-container');

`

Required when embedding multiple sketches on one page or integrating with frameworks.

WebGL Mode Gotchas

Export — Key Bindings Convention

Every sketch should include these in keyPressed():

`javascript

function keyPressed() {

if (key === 's' || key === 'S') saveCanvas('output', 'png');

if (key === 'g' || key === 'G') saveGif('output', 5);

if (key === 'r' || key === 'R') { randomSeed(millis()); noiseSeed(millis()); }

if (key === ' ') CONFIG.paused = !CONFIG.paused;

}

`

Headless Video Export — Use noLoop()

For headless rendering via Puppeteer, the sketch must use noLoop() in setup. Without it, p5's draw loop runs freely while screenshots are slow — the sketch races ahead and you get skipped/duplicate frames.

`javascript

function setup() {

createCanvas(1920, 1080);

pixelDensity(1);

noLoop(); // capture script controls frame advance

window._p5Ready = true; // signal readiness to capture script

}

`

The bundled scripts/export-frames.js detects _p5Ready and calls redraw() once per capture for exact 1:1 frame correspondence. See references/export-pipeline.md § Deterministic Capture.

For multi-scene videos, use the per-clip architecture: one HTML per scene, render independently, stitch with ffmpeg -f concat. See references/export-pipeline.md § Per-Clip Architecture.

Agent Workflow

When building p5.js sketches:

1. Write the HTML file — single self-contained file, all code inline

2. Open in browser — open sketch.html (macOS) or xdg-open sketch.html (Linux)

3. Local assets (fonts, images) require a server: python3 -m http.server 8080 in the project directory, then open http://localhost:8080/sketch.html

4. Export PNG/GIF — add keyPressed() shortcuts as shown above, tell the user which key to press

5. Headless export — node scripts/export-frames.js sketch.html --frames 300 for automated frame capture (sketch must use noLoop() + _p5Ready)

6. MP4 rendering — bash scripts/render.sh sketch.html output.mp4 --duration 30

7. Iterative refinement — edit the HTML file, user refreshes browser to see changes

8. Load references on demand — use skill_view(name="p5js", file_path="references/...") to load specific reference files as needed during implementation

Performance Targets

References

Creative Divergence (use only when user requests experimental/creative/unique output)

If the user asks for creative, experimental, surprising, or unconventional output, select the strategy that best fits and reason through its steps BEFORE generating code.

Conceptual Blending

1. Name two distinct visual systems (e.g., particle physics + handwriting)

2. Map correspondences (particles = ink drops, forces = pen pressure, fields = letterforms)

3. Blend selectively — keep mappings that produce interesting emergent visuals

4. Code the blend as a unified system, not two systems side-by-side

SCAMPER Transformation

Take a known generative pattern (flow field, particle system, L-system, cellular automata) and systematically transform it:

Distance Association

1. Anchor on the user's concept (e.g., "loneliness")

2. Generate associations at three distances:

- Close (obvious): empty room, single figure, silence

- Medium (interesting): one fish in a school swimming the wrong way, a phone with no notifications, the gap between subway cars

- Far (abstract): prime numbers, asymptotic curves, the color of 3am

3. Develop the medium-distance associations — they're specific enough to visualize but unexpected enough to be interesting