Rotors: A practical introduction for 3D graphics (2023)

Rotors: A practical introduction for 3D graphics 17 Apr 2023 When putting 3D graphics on a screen, we need a way to express rotations of the geometry we’re rendering. To avoid the problems that come with storing rotations as axes & angles, we could use quaternions. However quaternions require that we think in 4 distinct spatial dimensions, something humans are notoriously bad at. Thankfully there is an alternative that some argue is far more elegant and simpler to understand: Rotors. Rotors come from an area of mathematics called geometric algebra. Over the past few years I’ve seen a steady increase in the number of people claiming we should bin quaternions entirely in 3D graphics and replace them with rotors. I know nothing about either so I figured I’d try out rotors. I struggled to find educational materials online that clicked well with how I think about these things though, so this post is my own explanation of rotors and the surrounding mathematical concepts. It’s written with ... Read full article.