We’ve mentioned our implementation of Perlin simplex noise in GLSL in a couple of prior posts – this is now sometimes also referred to as “Ashima noise.” The paper describing the noise function was just published in the Journal of Graphics Tools. The paper is available in its final aesthetic form at the publisher’s website. A preproduction version (with the same informational content) is available from the arXiv.org site. The code is available via github .