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A comment on Geometric Algebra (2012). Parent comment

Re:Geometric Algebra (2012) by banachtarski on Monday November 30, 2020 @05:49AM (#25252505)
Quaternions are used in animation for blending and composing transforms for a reason. You don't have to trust me, but yes... tried for maybe ten years and counting from doing graphics and animation work.
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Re:Geometric Algebra (2012) by chombier on Monday November 30, 2020 @09:21AM (#25253960)
From the documentation of the Eigen library [0]:

> If the quaternion is used to rotate several points (>1) then it is much more efficient to first convert it to a 3x3 Matrix. Comparison of the operation cost for n transformations:

> - Quaternion2: 30n

> - Via a Matrix3: 24 + 15n

So really it depends on what you're doing (admittedly here it is 3x3 not 4x4)

[0] https://eigen.tuxfamily.org/dox/classEigen_1_1QuaternionBase...

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Re:Geometric Algebra (2012) by banachtarski on Tuesday December 01, 2020 @04:50PM (#25270438)
Right, as I said, composition is faster, not application.
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