in src/math/Matrix3.ts [67:80]
static RotationFromQuaternion(q: Quaternion): Matrix3 {
const matrix = new Matrix3(
1 - 2 * q.y * q.y - 2 * q.z * q.z,
2 * q.x * q.y - 2 * q.z * q.w,
2 * q.x * q.z + 2 * q.y * q.w,
2 * q.x * q.y + 2 * q.z * q.w,
1 - 2 * q.x * q.x - 2 * q.z * q.z,
2 * q.y * q.z - 2 * q.x * q.w,
2 * q.x * q.z - 2 * q.y * q.w,
2 * q.y * q.z + 2 * q.x * q.w,
1 - 2 * q.x * q.x - 2 * q.y * q.y,
);
return matrix;
}