/* Produce a quaternion from an axis-angle representation.*/
function quat_from_axis(theta: number, x: number, y: number, z: number) {
const halfcos = Math.cos(theta * 0.5);
const halfsin = Math.sin(theta * 0.5);
return new Quaternion(
halfcos,
axis[0] * halfsin,
axis[1] * halfsin,
axis[2] * halfsin,
);
}
Function is vibe coded.
feoren · 1m ago
What makes you so confident that you can tell that a 3-line function is AI? Especially given that the author denies it, with evidence.
noodlejs · 4m ago
Hi! Author here. I hand wrote this website and the source code of the examples mostly comes from my own debugging tools. That method in particular is just a very minimal implementation of section 8.5.2 of this textbook (but I tried to make it friendly for the blog post).
https://gamemath.com/book/orient.html#quaternion_geometry
A unit quaternion represents a rotation in R³.
A quaternion represents the quotient of two vectors in R³. That's what Hamilton had in mind.