unit quaternion drift

main.rs

use glam;
use rand::{thread_rng, Rng};

fn rand_angle<R: Rng>(rng: &mut R) -> f32 {
    rng.gen_range(-std::f32::consts::PI, std::f32::consts::PI)
}

fn rand_quat<R: Rng>(rng: &mut R) -> glam::Quat {
    let yaw = rand_angle(rng);
    let pitch = rand_angle(rng);
    let roll = rand_angle(rng);
    let result = glam::Quat::from_rotation_ypr(yaw, pitch, roll);
    assert!(result.is_normalized());
    result
}

fn main() {
    let mut rng = thread_rng();
    let mut result = rand_quat(&mut rng);
    let mut i = 0;
    loop {
        let a = result;
        let b = rand_quat(&mut rng);
        result = a * b;
        if !result.is_normalized() {
            println!("{}: {} * {} = {} |{}|", i, a, b, result, result.length());
            break;
        }
        i += 1;
    }
}