simplex-noise.js

simplex-noise.js is a fast simplex noise implementation in Javascript. It works in the browser and on nodejs.

Requirements

It requires typed arrays, if you want to use it in browsers without support you will need to use a polyfill like typedarray.js.

Demos

• Simple 2D plasma demo on codepen.io.
• A more complex 3D voxel world generation example.
• Real world usage for creating film grain in my analog film emulator.

Usage

By default simplex-noise.js will use Math.random() to seed the noise.

// initializing a new simplex instance
// do this only once as it is relatively expensive
var simplex = new SimplexNoise(),
    value2d = simplex.noise2D(x, y),
    value3d = simplex.noise3D(x, y, z),
    value4d = simplex.noise4D(x, y, z, w);

You can also pass in a seed string which will then be used to initialize the noise using the built in alea PRNG.

var simplex = new SimplexNoise('seed'),
    value2d = simplex.noise2D(x, y),
    sameSeed = new SimplexNoise('seed'),
    differentSeed = new SimplexNoise('different seed');

sameSeed.noise2D(x, y) === value2d
differentSeed.noise2D(x, y) !== value2d

You can also pass an alternative random function to the constructor that is used to build the permutation table. This can be used with a custom pseudo random number generator:

var random = new Alea(seed),
    simplex = new SimplexNoise(random),
    value2d = simplex.noise2D(x, y);

The ALEA PRNG can be found on in the npm package alea.

node.js

Node.js is also supported, you can install the package using npm.

var SimplexNoise = require('simplex-noise'),
    simplex = new SimplexNoise(Math.random),
    value2d = simplex.noise2D(x, y);

Benchmarks

• Comparison between 2D and 3D noise
• Comparison with simplex implementation in three.js

For development you can open perf/index.html and watch the console or run node perf/benchmark.js in a shell. There is also a rake task for comparing your current changes can also run make compare. The command works using git stash.

Tests

There are some simple unit tests for this library to run them

npm install && npm test

Changelog

2.4.0

• Included a PRNG based on ALEA to directly allow seeding
• Included typescript definitions

2.3.0

⚠️ This release changes the output of the noise functions. ⚠️

In the future such changes will be released as a new major version.

• Corrected generation of permutation table
• Moved tests to mocha/chai
• Cleanup

2.2.0

• Small performance improvement for 2D noise

2.1.1

• Increased entropy by fixing a little initialization issue.

2.1.0

• AMD support

2.0.0

• Changed node.js api, SimplexNoise is now exported directly.
• Added unit tests

1.0.0

• Initial Release

License

Copyright (c) 2015 Jonas Wagner, licensed under the MIT License (enclosed)

Credits

This is mostly a direct javascript port of the Java implementation by Stefan Gustavson and Peter Eastman.

The integrated pseudo random generator is based on code by by Johannes Baagøe.

The typescript definition has been provided by Neonit.