Is there a Quaternion master ?

[LeGreg]

pourquoi ?

ben juste bonne chance pour ton projet.

C'est tout.

LeGreg

 

[darkblu]

It's a good point. I should have put quotes around 'real'. I'm not a mathematician, my background is in physics, so I can visualise and manipulate vectors 'til the cows come home - while I have no idea what the phrase 'matrices represent bases of spaces' means .

that be because my wording used in this case (and in 95% of the rest of the cases, i'm affraid) was pretty loose. a vector-space base would have been the correct term - a set of N linearly-independent vectors, defining the base of a coodinate system with N dimensions. you then pack those vectors the right way in a matrix (possibly with a homogeneous part) and voila - there's your matrix transformation ; )

Of course, this is just me demonstrating my stupidity. My experience with maths is mostly with mathemagicians, where three rules hold:
1. They always know an answer, but there's no danger of me understanding it
2. They invariably turn out to be right
3. Sometimes - rarely - there are hacks that they miss

So I was describing one of the methods I've seen that maths fools like me might have a better time with if they find matrix math hairy.

while this board is yet to see a 'demonstation of your stupidity', i absolutely second your three points of view at math (me being a math mediocrite at large), just that with linear algebra it's pretty much an intuitive process - one can learn to envision pretty much any entity from it, includingly matrix transformations : )

ed: yet another example of my inabily to write anything sensible in a human language

 

[Dio]

Ah, now that starts to sound like some of the stuff I didn't understand in my plasma physics (which is where 'real' vectors get really hairy). I can hear the words 'eigenvector' and 'eigenvalue' approaching... like the front of an oncoming train.

The general agreement on that course was that Maxwell was an evil git.

 

[Simon F]

Ah, now that starts to sound like some of the stuff I didn't understand in my plasma physics (which is where 'real' vectors get really hairy). I can hear the words 'eigenvector' and 'eigenvalue' approaching... like the front of an oncoming train.

Funnily enough, I just wrote my own routine to find the principal eigenvector - quite important for texture compression (VQ, S3TC, and PVR-TC).

 

[Zeross]

pourquoi ?

ben juste bonne chance pour ton projet.

C'est tout.

LeGreg

Ah ouf tu me rassures j'ai cru que c'était une mise en garde contre un éventuel futur problème. En tout cas merci pour tes conseils et pour tes encouragements

 

[Dio]

Funnily enough, I just wrote my own routine to find the principal eigenvector - quite important for texture compression (VQ, S3TC, and PVR-TC).

See point 3 above

 

[Simon F]

Funnily enough, I just wrote my own routine to find the principal eigenvector - quite important for texture compression (VQ, S3TC, and PVR-TC).

See point 3 above

I don't quite get what you mean although I think my new code falls into a "sort of hack" category. I had been using an "off the shelf" routine that found all the eigenvectors when I really only wanted the biggest one. This is what the new code does and has the big advantage of being very simple. I based it on a hint Konstantine Iourcha gave me while at Siggraph.

 

[Dio]

Ah, well, Konstantine is the mathemagician. Original and best. Whenever I say 'It Depends' it tends to come out in a Russian accent nowadays.