June 23, 2026
Rotational drama, now with receipts
Matrix and Quaternion FAQ
Old math guide sparks fresh panic as commenters call parts flat-out wrong
TLDR: The revived Matrix and Quaternion FAQ is an old guide for tricky 3D math, but commenters say some of its formulas can mislead people in real projects. The big fight is whether it’s a handy shortcut or a dangerous oversimplification unless you already know the subject well.
A dusty old internet classic, the Matrix and Quaternion FAQ, has resurfaced with all the chaotic energy of a beloved handbook that everyone used, nobody fully trusted, and several people quietly patched over the years. The document itself reads like a time capsule from the early web: bounced emails, vanished sites, a long list of corrections, and a maintainer openly begging readers not to send him math questions because he’s "only maintaining this FAQ." Honestly? That line alone has people cackling.
But the real fireworks are in the reactions. One camp says this kind of cheat sheet is a lifesaver for game and graphics developers trying to make objects rotate properly on screen. The other camp is basically yelling, "Do not trust this thing with your life." Commenter xeonmc went in hard, calling key formulas "terrible" and saying they only work in a perfect world where the numbers are already perfectly cleaned up. Translation for normal humans: some of the instructions may look simple, but can break in real-world use. Ouch.
Then came the cooler-headed pushback. fsloth’s vibe was less roast, more warning label: cheat sheets are fine if you already know what you’re doing and can spot when the guide doesn’t match your problem. That sparked the classic internet split between "practical shortcut" and "read an actual textbook." The unintentional comedy here is brutal: a FAQ with decades of edits, corrections, and rescues is now being treated like both sacred scripture and a cursed relic.
Key Points
- •The document is **Version 1.21** of the *Matrix and Quaternion FAQ*, dated **30 November 2003**.
- •The FAQ provides a feedback email address, a subject-line requirement for messages, and a public URL where the latest version is hosted.
- •The article includes a detailed contributions list crediting multiple individuals for corrections, clarifications, optimizations, and additions to specific sections.
- •The history section says Andreas assumed maintenance after earlier hosting locations and contact addresses became unavailable and after problems were found in earlier algorithms.
- •The FAQ’s structure includes introductory notes on **OpenGL** and **normalized inputs**, followed by basic questions about matrices and their representation in **C/C++**.