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user2994cb
I forgot to add (1945) to the title, apologies.
h0p3
Where is Adam Nemecek? (https://news.ycombinator.com/user?id=adamnemecek)

/press Quaternion Alert button

user2994cb
> Location: Los Angeles, Prague

It's still a bit early if he's in LA, particularly as it's Sunday.

h0p3
True dat. Alright, well, I'll help him out with his obligatory link:

http://www.chinedufn.com/dual-quaternion-shader-explained/

user2994cb
Interesting stuff. Maybe there is a connection with the use of quaternion pairs to represent rotations in 4-space (as in the Coxeter paper).
theoh
Using quaternion pairs for 4-space rotations relies on the simple fact that each quaternion represents a hyperplane in 4-space (https://en.wikipedia.org/wiki/Transformation_geometry). Using single quaternions to represent rotations in 3-space is geometrically a different mechanism, which AFAIK doesn't have such a simple geometrical explanation.