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Quaternions and Reflections (1946) [pdf] (utah.edu)
22 points by user2994cb 4 months ago | hide | past | web | favorite | 6 comments



Where is Adam Nemecek? (https://news.ycombinator.com/user?id=adamnemecek)

/press Quaternion Alert button


> Location: Los Angeles, Prague

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


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

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


Interesting stuff. Maybe there is a connection with the use of quaternion pairs to represent rotations in 4-space (as in the Coxeter paper).


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.


I forgot to add (1945) to the title, apologies.




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