Rediscovering Quaternions

Post by vrighter » Fri, Feb 28, 2025, 10:45 AM UTC

thaumasiotes wrote: post #53

nighthawk454 wrote: post #29

The easiest way for me to conceptualize it is to think of it as orientation + rotation. 3 dims for the orientation vector to get the object facing/pointing the right way, then a further 1 dim/var for rotation about that axis. For a total of 4 variables/dimensions 3blue1brown and Ben Eater did a series of interactive videos on the subject that can be explored: https://eater.net/quaternions My favorite demo on this poi…

> The easiest way for me to conceptualize it is to think of it as orientation + rotation. 3 dims for the orientation vector to get the object facing/pointing the right way, then a further 1 dim/var for rotation about that axis. For a total of 4 variables/dimensions Something's missing. Orientation in 3D space is a two-dimensional quantity; you would never need three dimensions to express it. The third dimension has t…

I think a better word than orientation is "axis". They are conceptually similar to axis-angle, with some added sugar to make an algebra

Post by ahazred8ta » Sat, Mar 01, 2025, 12:39 AM UTC

lawlessone wrote: post #66

xanderlewis wrote: post #26

Earlier quoted context omitted.

What in particular did you find difficult about dealing with them?

There was something called a slerp that allowed you to get an object to rotate from on orientation to another, similar to a linear interpolation. This was fine for some things. but if you wanted something to rotate but only in a certain way it was annoying as sometimes it would get from A to B, but go through Z during its rotation. Getting the order or multiplications right too.

Spherical linear interpolation, slerp https://en.wikipedia.org/wiki/Slerp (which can sometimes wrap around the wrong way)

For levity, see Acts 12:4 And when he had apprehended him, he put him in prison, and delivered him to four quaternions of soldiers to keep him.

Re: Rediscovering Quaternions

Re: Rediscovering Quaternions