I’ve read your post and I just want thank you for your very kind words. I’m sincerely flattered.

]]>I assume you are referring to the lights in the scene? I usually use the “space” key on the keyboard to toggle the animations. Can you try that?

]]>And the mnemonic about directions is really helpful, thank you! ]]>

while your formulae are correct, an explanation is missing

why in qp=(q0p0-q1p1-q2p2-q3p3,…. 3 components are subtracted

and in dot(q,p)=q0p0+q1p1+q2p2+q3p3.

It is so in complex and/or quaternion dot product one argument is

taken conjugate before multiplying so eg: q conjg(p) = (dot(q,p),….) ]]>

1) In the second example of the “rotations” part. It seems that the vector p = [2, 0, 0] revolves 60 degrees instead of 90 since the angle between p and v is 60. Therefore, the deduction of the “rotor” in quaternion form seems to be incorrect.

2) I try to get a formula of rotors in quaternion form and I get one. But somehow I could not get the correct result with p = [2, 0, 0] and v = [sqrt(2) / 2, 0, sqrt(2) / 2]. I calculated for more than 10 times, the formula seems to be correct.

(Here I ignore my uncertainties I talked about in 1))

The formula I get is:

q*p*inverse(p) = p + sin(theta) * cross(v, p) – sin(theta / 2) * sin(theta / 2) * cross(cross(v, p), v) ]]>

Sorry about that! I had 2 files with the same name and I accidentally linked the wrong one. The link has now been fixed (really this time).

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