generative-series

Hash-seeded generative series

A series is one sketch that yields a unique piece per hash, and the same hash always yields the same piece. Everything random must flow from a single seeded RNG derived from the hash.

1. Deterministic RNG from the hash

Never call Math.random(). Seed a small PRNG from the token hash.

fxhash provides $fx.rand() (uniform 0..1, deterministic from the token). Wrap it:

// fxhash: $fx.rand() is already deterministic per token
const R = () => $fx.rand()

Generic / Art Blocks-style (hash → seeded PRNG):

function mulberry32(a){ return function(){ let t=a+=0x6D2B79F5; t=Math.imul(t^t>>>15,t|1); t^=t+Math.imul(t^t>>>7,t|61); return ((t^t>>>14)>>>0)/4294967296 } }
function seedFromHash(hash){ let h=1779033703^hash.length; for(let i=0;i<hash.length;i++){ h=Math.imul(h^hash.charCodeAt(i),3432918353); h=h<<13|h>>>19 } return h>>>0 }
const R = mulberry32(seedFromHash(tokenData.hash))   // Art Blocks: tokenData.hash

Use R() for all randomness; derive helpers: rint=(a,b)=>Math.floor(a+R()*(b-a)), pick=arr=>arr[Math.floor(R()*arr.length)].

2. Define features / traits

Pick high-level choices from R() and expose them so platforms can index rarity:

const PALETTES = { Ember:['#ff6b5c','#ffb347'], Tide:['#3ad6c5','#5b8cff'], Orchid:['#e85aff','#7c5cff'] }
const paletteName = pick(Object.keys(PALETTES))
const density = pick(['Sparse','Balanced','Dense'])
const technique = R() < 0.15 ? 'Rare-Variant' : 'Classic'   // rarity via thresholds

// fxhash:
$fx.features({ Palette: paletteName, Density: density, Technique: technique })
// Art Blocks: expose window.$generativeTraits or log for the script

Draw the piece deterministically from these traits + R().

3. Deterministic preview

Platforms snapshot a still. Make sure the canvas reaches its final, stable frame quickly (or signal readiness):

// fxhash: call when the artwork is rendered and ready to capture
$fx.preview()

4. Project hygiene

• Self-contained bundle; pin library versions (no CDN drift).
• Fixed aspect ratio; scale all sizes relative to canvas so it renders at any resolution (thumbnail → print).
• Test determinism: render the same hash twice → pixel-identical. Render many random hashes → variety without ugly outliers (clamp the bad regions of your parameter space).
• Keep a ?seed= / hash override for local testing so you can browse the space.

5. Sanity checklist before mint

• No unseeded randomness anywhere (search for Math.random).
• Same hash → identical output (verified).
• Features exposed and rarities feel right across ~100 sample hashes.
• Renders cleanly at low and very high resolution.
• Preview/capture fires at the right moment.

Hand off

• The art itself → generative-systems / p5-sketch-engine / shader-artist; palette as a trait → color-composition; high-res/video capture → art-export-engineer (/export-art).