NOISE(3G)

💖 NAME 💖

noise — bestie, this is the one that generates values with a pseudo-random noise function ✨

so real quick, this page lives in section 3G of the manual (iykyk, that's the OpenGL shader function corner of the world) 🎀

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🌸 DECLARATION 🌸

okay so here's the whole squad, no notes:

float noise1(genType x);

vec2 noise2(genType x);

vec3 noise3(genType x);

vec4 noise4(genType x);

four besties, four different return shapes, one shared vibe 💅

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✨ PARAMETERS ✨

• x — this is the value you're seeding the noise function with. like, the lil starting point that everything grows from 🦋

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🫶 DESCRIPTION 🫶

okay so noise1, noise2, noise3 and noise4 hand you back noise values — could be a vector, could be a scalar — based on the input value x. The noise function is a stochastic function, which is the fancy way of saying it's here to crank up your visual complexity, periodt. 🌈

here's the thing though: the values that come out give the appearance of randomness, but they are not truly random. it's giving random, it's not actually random. very demure, very mindful. 🙈

They're defined to have the following characteristics, and you're gonna wanna remember these:

• The return value(s) are always in the range [-1.0,1.0], and cover at least the range [-0.6, 0.6], with a Gaussian-like distribution. 📊
• The return value(s) have an overall average of 0.0. balanced. centered. main character energy.
• They are repeatable, in that a particular input value will always produce the same return value. same input, same output, every single time, no cap 🔥
• They are statistically invariant under rotation — i.e., no matter how the domain is rotated, it has the same statistical character. spin it however you want bestie, the vibe does not change 💫
• They have a statistical invariance under translation — i.e., no matter how the domain is translated, it has the same statistical character. slide it around, same vibe ✨
• They typically give different results under translation. (yes, both of those are true at once, it's giving nuance 💅)
• The spatial frequency is narrowly concentrated, centered somewhere between 0.5 to 1.0. 🎯
• They are C1 continuous everywhere — i.e., the first derivative is continuous. smooth like butter, no jagged edges, we love to see it 🧈

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👑 VERSION SUPPORT 👑

the table said "every function, every version, all checks" so let me just spell that out for you so nothing gets lost, bestie. every single one of these is a ✔ in OpenGL Shading Language Version 1.10, 1.20, 1.30, 1.40, 1.50, 3.30, 4.00, 4.10, 4.20, 4.30, 4.40 and 4.50:

• noise1 — ✔ 1.10, ✔ 1.20, ✔ 1.30, ✔ 1.40, ✔ 1.50, ✔ 3.30, ✔ 4.00, ✔ 4.10, ✔ 4.20, ✔ 4.30, ✔ 4.40, ✔ 4.50
• noise2 — ✔ 1.10, ✔ 1.20, ✔ 1.30, ✔ 1.40, ✔ 1.50, ✔ 3.30, ✔ 4.00, ✔ 4.10, ✔ 4.20, ✔ 4.30, ✔ 4.40, ✔ 4.50
• noise3 — ✔ 1.10, ✔ 1.20, ✔ 1.30, ✔ 1.40, ✔ 1.50, ✔ 3.30, ✔ 4.00, ✔ 4.10, ✔ 4.20, ✔ 4.30, ✔ 4.40, ✔ 4.50
• noise4 — ✔ 1.10, ✔ 1.20, ✔ 1.30, ✔ 1.40, ✔ 1.50, ✔ 3.30, ✔ 4.00, ✔ 4.10, ✔ 4.20, ✔ 4.30, ✔ 4.40, ✔ 4.50

not a single ❌ in sight. the way that they ate and left no crumbs 😭👑

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💜 COPYRIGHT 💜

Copyright © 2011-2014 Khronos Group. This material may be distributed subject to the terms and conditions set forth in the Open Publication License, v 1.0, 8 June 1999. http://opencontent.org/openpub/.

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💜 COPYRIGHT 💜

Copyright © 2011-2014 Khronos Group

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and that's the whole page bestie!! 🎀 this lil masterpiece is from [FIXME: source] and it's dated 01/03/2018 — it's the NOISE(3G) page, go forth and make some extremely non-random noise, mwah 💖✨🦋