Quaternions 
3joez 
The most obscure topic on 3d graphics. Is there somebody knowing something about it and willing to share a simple explanation? I just know they represent a rotation. That's it.
read 540 times 11/7/2014 10:17:54 AM (last edit: 11/7/2014 10:17:54 AM)

reeves1984 
In what context  Im sure context is irellevant to your actual question, but I'm curious..
I know some of the basics when it comes to vector maths from doing stuff in ICE in xsi... It has been good to learn those fundamentals..
Here it is in ICE, so its a vector with an angle.....Like a roll on a camera...
https://www.dropbox.com/s/za7sz3yc69b2s14/Screenshot%2020141107%2010.03.10.png
 Simon Reeves
www.simonreeves.com  VFX Artist & Blog twitter
www.analogstudio.co.uk < I work here
read 537 times 11/7/2014 10:56:31 AM (last edit: 11/7/2014 11:04:07 AM)

LionDebt 
From what I've gathered through Unity development...
1. A quaternion is just a compact way of representing a rotation. 2. They can easily be interpolated and don't suffer from gimbal lock. 3. They are based on complex numbers (which leads into 4.) 4.The mathematics involved is mind boggling  so quaternions are (pretty much) never modified directly. 5. Luckily they are used internally in Unity and we can access rotations with euler angles which are much easier to understand. 6. Quaternions were first described by an irish mathematician... Which, really, goes to show how incomprehensible they are.
read 512 times 11/7/2014 2:34:21 PM (last edit: 11/7/2014 2:34:21 PM)

Mr_Stabby 
A quaternion is 2 vectors in 2d space that form 1 vector in 3d space. Not really made for human consumption, its popular because its easy to handle by matrices (what modern gpu's are hardware optimized for). Anything a quaternion can represent, a xyz can just as well.
read 497 times 11/7/2014 6:28:17 PM (last edit: 11/7/2014 6:28:17 PM)

Ktonne 
there you go:
read 496 times 11/7/2014 6:33:28 PM (last edit: 11/7/2014 6:33:28 PM)

Octopuzzy 
Ask the almighty Youtube..they have a bunch of videos attempting to explain quaternions..one of em might bite.
read 493 times 11/7/2014 6:55:52 PM (last edit: 11/7/2014 6:55:52 PM)

aca88 
You can find a complete explanation of quaternions in this phd:
http://characters.media.mit.edu/Theses/johnson_phd.pdf
By the way, quaternions are much more simplified when used in 3d graphics, than they are actually used in math.
read 449 times 11/10/2014 8:45:44 AM (last edit: 11/10/2014 8:45:44 AM)

3joez 
Thanks aca,88 I'll stick to quaternions. Then I'm waiting for a tutorial to use sedenions in cg...
read 412 times 11/13/2014 11:42:32 AM (last edit: 11/13/2014 11:42:32 AM)
