p5js

name	p5js
description	p5.js sketches: generative art, shaders, interactive, 3D, data viz, animations, audio-reactive visuals, canvas-based creative coding. Use when the user asks for p5.js sketches, creative coding, generative art, interactive visualizations, canvas animations, browser-based visual art, data viz, shader effects, or any p5.js project.
license	MIT
metadata	{"author":"hakase (ported via Hermes Agent; skill by Hermes Agent, library p5.js by Lauren Lee McCarthy / Processing Foundation, LGPL-2.1)","version":"1.0.0","source":"https://github.com/NousResearch/hermes-agent/tree/main/skills/creative/p5js"}

p5.js Production Pipeline

When to use

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.

What's inside

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.

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

Mode	Input	Output	Reference
Generative art	Seed / parameters	Procedural visual composition (still or animated)	references/visual-effects.md
Data visualization	Dataset / API	Interactive charts, graphs, custom data displays	references/interaction.md
Interactive experience	None (user drives)	Mouse/keyboard/touch-driven sketch	references/interaction.md
Animation / motion graphics	Timeline / storyboard	Timed sequences, kinetic typography, transitions	references/animation.md
3D scene	Concept description	WebGL geometry, lighting, camera, materials	references/webgl-and-3d.md
Image processing	Image file(s)	Pixel manipulation, filters, mosaic, pointillism	references/visual-effects.md § Pixel Manipulation
Audio-reactive	Audio file / mic	Sound-driven generative visuals	references/interaction.md § Audio Input

Stack

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

Layer	Tool	Purpose
Core	p5.js 1.11.3 (CDN)	Canvas rendering, math, transforms, event handling
3D	p5.js WebGL mode	3D geometry, camera, lighting, GLSL shaders
Audio	p5.sound.js (CDN)	FFT analysis, amplitude, mic input, oscillators
Export	Built-in saveCanvas() / saveGif() / saveFrames()	PNG, GIF, frame sequence output
Capture	CCapture.js (optional)	Deterministic framerate video capture (WebM, GIF)
Headless	Puppeteer + Node.js (optional)	Automated high-res rendering, MP4 via ffmpeg
SVG	p5.js-svg 1.6.0 (optional)	Vector output for print — requires p5.js 1.x
Natural media	p5.brush (optional)	Watercolor, charcoal, pen — requires p5.js 2.x + WEBGL
Texture	p5.grain (optional)	Film grain, texture overlays
Fonts	Google Fonts / loadFont()	Custom typography via OTF/TTF/WOFF2

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

Dimension	Options	Reference
Color system	HSB/HSL, RGB, named palettes, procedural harmony, gradient interpolation	references/color-systems.md
Noise vocabulary	Perlin noise, simplex, fractal (octaved), domain warping, curl noise	references/visual-effects.md § Noise
Particle systems	Physics-based, flocking, trail-drawing, attractor-driven, flow-field following	references/visual-effects.md § Particles
Shape language	Geometric primitives, custom vertices, bezier curves, SVG paths	references/shapes-and-geometry.md
Motion style	Eased, spring-based, noise-driven, physics sim, lerped, stepped	references/animation.md
Typography	System fonts, loaded OTF, textToPoints() particle text, kinetic	references/typography.md
Shader effects	GLSL fragment/vertex, filter shaders, post-processing, feedback loops	references/webgl-and-3d.md § Shaders
Composition	Grid, radial, golden ratio, rule of thirds, organic scatter, tiled	references/core-api.md § Composition
Interaction model	Mouse follow, click spawn, drag, keyboard state, scroll-driven, mic input	references/interaction.md
Blend modes	BLEND, ADD, MULTIPLY, SCREEN, DIFFERENCE, EXCLUSION, OVERLAY	references/color-systems.md § Blend Modes
Layering	createGraphics() offscreen buffers, alpha compositing, masking	references/core-api.md § Offscreen Buffers

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 (use read_file on the bundled file at .agents/skills/p5js/templates/viewer.html), 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:

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Project Name</title>
  <script>p5.disableFriendlyErrors = true;</script>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/p5.js/1.11.3/p5.min.js"></script>
  <!-- <script src="https://cdnjs.cloudflare.com/ajax/libs/p5.js/1.11.3/addons/p5.sound.min.js"></script> -->
  <!-- <script src="https://unpkg.com/p5.js-svg@1.6.0"></script> -->  <!-- SVG export -->
  <!-- <script src="https://cdn.jsdelivr.net/npm/ccapture.js-npmfixed/build/CCapture.all.min.js"></script> -->  <!-- video capture -->
  <style>
    html, body { margin: 0; padding: 0; overflow: hidden; }
    canvas { display: block; }
  </style>

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 system_exec for 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

Format	Method	Command
PNG	saveCanvas('output', 'png') in keyPressed()	Press 's' to save
High-res PNG	Puppeteer headless capture	system_exec for node .agents/skills/p5js/scripts/export-frames.js sketch.html --width 3840 --height 2160 --frames 1
GIF	saveGif('output', 5) — captures N seconds	Press 'g' to save
Frame sequence	saveFrames('frame', 'png', 10, 30) — 10s at 30fps	Then system_exec for ffmpeg -i frame-%04d.png -c:v libx264 ./outputs/output.mp4
MP4	Puppeteer frame capture + ffmpeg	system_exec for bash .agents/skills/p5js/scripts/render.sh sketch.html ./outputs/output.mp4 --duration 30 --fps 30
SVG	createCanvas(w, h, SVG) with p5.js-svg	save('output.svg')

Step 6: Quality Verification

• Does it match the vision? Compare output to the creative concept. If it looks generic, go back to Step 1
• Resolution check: Is it sharp at the target display size? No aliasing artifacts?
• Performance check: Does it hold 60fps in browser? (30fps minimum for animations)
• Color check: Do the colors work together? Test on both light and dark monitors
• Edge cases: What happens at canvas edges? On resize? After running for 10 minutes?

Critical Implementation Notes

Performance — Disable FES First

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

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:

// In draw() or update() hot paths:
let a = Math.sin(t);          // not sin(t)
let r = Math.sqrt(dx*dx+dy*dy); // 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.

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:

// 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:

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:

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:

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:

// 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:

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

• createCanvas(w, h, WEBGL) — origin is center, not top-left
• Y-axis is inverted (positive Y goes up in WEBGL, down in P2D)
• translate(-width/2, -height/2) to get P2D-like coordinates
• push()/pop() around every transform — matrix stack overflows silently
• texture() before rect()/plane() — not after
• Custom shaders: createShader(vert, frag) — test on multiple browsers

Export — Key Bindings Convention

Every sketch should include these in keyPressed():

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.

function setup() {
  createCanvas(1920, 1080);
  pixelDensity(1);
  noLoop();                    // capture script controls frame advance
  window._p5Ready = true;      // signal readiness to capture script
}

The bundled .agents/skills/p5js/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 system_exec for 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 — xdg-open sketch.html (Linux) or the platform equivalent
3. Local assets (fonts, images) require a server: use system_exec for 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 — use system_exec for node .agents/skills/p5js/scripts/export-frames.js sketch.html --frames 300 for automated frame capture (sketch must use noLoop() + _p5Ready)
6. MP4 rendering — use system_exec for bash .agents/skills/p5js/scripts/render.sh sketch.html ./outputs/output.mp4 --duration 30
7. Iterative refinement — edit the HTML file, user refreshes browser to see changes
8. Load references on demand — use read_file on the bundled reference files (e.g., read_file on .agents/skills/p5js/references/color-systems.md) as needed during implementation

Performance Targets

Metric	Target
Frame rate (interactive)	60fps sustained
Frame rate (animated export)	30fps minimum
Particle count (P2D shapes)	5,000-10,000 at 60fps
Particle count (pixel buffer)	50,000-100,000 at 60fps
Canvas resolution	Up to 3840x2160 (export), 1920x1080 (interactive)
File size (HTML)	< 100KB (excluding CDN libraries)
Load time	< 2s to first frame

References

File	Contents
references/core-api.md	Canvas setup, coordinate system, draw loop, push()/pop(), offscreen buffers, composition patterns, pixelDensity(), responsive design
references/shapes-and-geometry.md	2D primitives, beginShape()/endShape(), Bezier/Catmull-Rom curves, vertex() systems, custom shapes, p5.Vector, signed distance fields, SVG path conversion
references/visual-effects.md	Noise (Perlin, fractal, domain warp, curl), flow fields, particle systems (physics, flocking, trails), pixel manipulation, texture generation (stipple, hatch, halftone), feedback loops, reaction-diffusion
references/animation.md	Frame-based animation, easing functions, lerp()/map(), spring physics, state machines, timeline sequencing, millis()-based timing, transition patterns
references/typography.md	text(), loadFont(), textToPoints(), kinetic typography, text masks, font metrics, responsive text sizing
references/color-systems.md	colorMode(), HSB/HSL/RGB, lerpColor(), paletteLerp(), procedural palettes, color harmony, blendMode(), gradient rendering, curated palette library
references/webgl-and-3d.md	WEBGL renderer, 3D primitives, camera, lighting, materials, custom geometry, GLSL shaders (createShader(), createFilterShader()), framebuffers, post-processing
references/interaction.md	Mouse events, keyboard state, touch input, DOM elements, createSlider()/createButton(), audio input (p5.sound FFT/amplitude), scroll-driven animation, responsive events
references/export-pipeline.md	saveCanvas(), saveGif(), saveFrames(), deterministic headless capture, ffmpeg frame-to-video, CCapture.js, SVG export, per-clip architecture, platform export (fxhash), video gotchas

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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 — when the user names two things to combine or wants hybrid aesthetics
• SCAMPER — when the user wants a twist on a known generative art pattern
• Distance Association — when the user gives a single concept and wants exploration ("make something about time")

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:

• Substitute: replace circles with text characters, lines with gradients
• Combine: merge two patterns (flow field + voronoi)
• Adapt: apply a 2D pattern to a 3D projection
• Modify: exaggerate scale, warp the coordinate space
• Purpose: use a physics sim for typography, a sorting algorithm for color
• Eliminate: remove the grid, remove color, remove symmetry
• Reverse: run the simulation backward, invert the parameter space

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

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Ported to hakase from Hermes Agent (MIT). Skill by Hermes Agent (MIT). Underlying library: p5.js by Lauren Lee McCarthy / the Processing Foundation (LGPL-2.1).