3 ms·
I am going to be the HN pedant here, and for that I apologize. Quaternions don't specifically need to be unit vectors or points on a 4-D hypersphere. They are
by pclmulqdq 3y ago
I am going to be the HN pedant here, and for that I apologize.
Quaternions don't specifically need to be unit vectors or points on a 4-D hypersphere. They are any number with 3 imaginary parts and 1 real part. Being a unit operator is a property of a rotation (this holds true even if you aren't using quaternions or if you extend to n-dimensional rotations), not a property of quaternions.
- andersa 3y agoIn the context of game development, "quaternion" almost always refers to a normalized one that represents a rotation. Many engines aren't even capable of representing anything else with their quaternion types and enforce this automatically.
- pclmulqdq 3y agoThat's probably because pretty much all uses of quaternions in games are for rotations, which involve normalized vectors. As a mathematical concept, quatetnions are far broader and more applicable than just rotations. This is a generic mathematical concept, not something specific to graphics.