Simplex Noise

Fewer directional artefacts, cheaper in higher dimensions.

patterns.simplex · v1 · renderer canvas

Clouds · 5 octaves · zoom 3.0 · 7 colours

A square lattice has axes, so Perlin features lean towards 0°, 45° and 90°. An equilateral lattice has no preferred direction, and the 24 gradient vectors are spaced every 15° rather than Perlin's eight. Turn on Compare to see both halves of the same field, normalised together.

[data-canvas-stage] { display: none; }

Drawn in the browser

This generator does not send you an image. The server sends a short description of one — the parameters below, plus a 32-byte key — and the drawing is done here, from the same byte stream the server would have used. That needs JavaScript, so with it switched off there is nothing to show.

The description itself is still public: /api/v1/g/patterns.simplex returns it, and the maths is in resources/js.

Clouds · 5 octaves · zoom 3.0 · 7 colours

Controls · from schema()

Width

200 2048

Height

200 2048

Zoom

0.5 16

How many lattice cells fit across the canvas.

Detail (octaves)

1 9

One octave is plain OpenSimplex2. Each one adds finer detail at half the strength.

Roughness

0.2 0.85

Frequency step

1.4 3.2

Shape

Domain warp

0 1.2

Folds the noise through a copy of itself.

Compare with Perlin

Splits the canvas: OpenSimplex2 left, Perlin right, same seed and same settings. Perlin's square lattice shows as a faint grain along the axes.

Colour

Palette size

2 12

Banding

Quantise into flat bands instead of a smooth gradient.

Entropy source

Picking a source changes the story on the receipt, never the quality: anything below class A is mixed with the OS CSPRNG before it reaches you. This result actually came from Operating System CSPRNG.

seed token Y2A7X1GD5109TD7HNBMBYBRSS4

Re-render keeps this token. Generate replaces it. That is the whole idea.

Burned into the corner before the file is written, so the image keeps its provenance wherever it ends up:

entropy in

16 bytes

stream used

18 bytes

rejections

duration

52 µs

palette

lattice

triangular (OpenSimplex2)

corners per sample

perlin corners per sample

gradient directions

Seed receipt

Class A · Cryptographic degraded

Drawn from the kernel entropy pool on the server that rendered this page. (The source you picked was unreachable, so we fell back to the kernel.)

source: Operating System CSPRNG
observed: 2026-09-14T17:21:39+00:00
latency: 1510ms
mixed with: nothing — this source stands alone

This source publishes no per-draw proof URL.

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The token is the seed, so this link recomputes the result rather than looking it up. No database, and it works for as long as v1 does.

This page and /api/v1/g/patterns.simplex run the same code. There is no private endpoint.

Simplex Noise

Result

Measurements

Seed receipt

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