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why is it that the venn diagram of people who understand 3d rotation math and people who do not know how to explain things is a circle

ME: what's a quaternion?

NERD: it's a four-dimensional complex number of the form (a + bi + cj + dk) where a, b, c and d are real numbers and i^2 = j^2 = k^2 = ijk = -1!

ME: ok. i understand that. but don't people use these for 3d rotations?

NERD: yeah!

ME: how?

NERD:

NERD:

NERD: well, you see, they're very important to use for rotations because they prevent gimbal lock,

@prophet_goddess something something rotors

@prophet_goddess *snicker* he doesn’t understand the three seashells.

@prophet_goddess that’s not entirely untrue. the idea of university being for anyone other than the ruling class is extremely recent, and so a good proportion of its trappings are just about teaching you basically rich people gang signs.

the fact that mathematics turned out to be useful for things other than than games for rich kids is kind of an accident.

@zensaiyuki there is perhaps no field more prone to this than economics.

@prophet_goddess same with monads

@er1n i'm not even convinced monads are real.

@prophet_goddess @er1n “a monad is just a monoid in the category of functors”

@prophet_goddess hello how can i help

@prophet_goddess by specific i mean "known"

@prophet_goddess excellent. one last question - which math tool are you using

@dankwraith i don't understand the question?

@prophet_goddess like are you using System.Numerics, Microsoft.Xna.Framework, Unity, etc

@dankwraith oh, microsoft.xna.framework

@prophet_goddess cool cool one moment please

@prophet_goddess i think this will do it:

var rotation = Quaternion.Multiply(targetDirection, Quaternion.Inverse(startDirection));

@prophet_goddess oh wait uh you need to convert the directions to quaternions too

@prophet_goddess i am currently applying my two brain cells to this problem, one moment please

@dankwraith I have both of those!

@prophet_goddess allllmost got it one sec please

@dankwraith this whips. thank you so much! I'll check it as soon as I'm back at my computer!

ludum tsundare@prophet_goddess@skeleton.coolthis is a dispatch from quaternion hell