[PD] Free rotation in GEM
matju at artengine.ca
Wed Jul 16 06:02:59 CEST 2008
On Wed, 16 Jul 2008, PSPunch wrote:
> I have not looked into GridFlow much, but I had the impression that its
> main concept was to add matrix manipulation features to Pd, all of its
> visual capabilities being just one of the many results of data you can
> manipulate with matrix.
Well, that's sort of it, if you use the name 'matrix' as taken from
Jitter, or as taken from a plain linear algebra system that has been
expanded to higher-order structures. I mean that in math, 'matrix' is
limited to mean a grid of weights that make inputs correspond to outputs.
the indices of that grid are 2-dimensional, with the rows representing
inputs and the columns representing outputs or the other way around
depending on which way you prefer it (or which way your software prefers
it). The concept of 'matrix' as you would find in Jitter is something more
generic, meaning that it's more about just storage than any particular
operators... math is much more operator-oriented: matrices are matrices
because of how you add and multiply them.
> Anyway, understanding its marvelous potentials, I have lately been stuck
> with Windows platforms. At least I got your point that utilizing
> GridFlow only for crunching numbers may work but not so efficient.
No, you didn't get my point. I was talking about quaternions in
particular, and not even in comparison to how else you could possibly do
any quaternions in Pd.
Well, GridFlow is fine for number crunching, but it depends what. I don't
recall anything in Pd that directly supports quaternions. Depending on
what plugins you can use, you may or may not have a way to cook your own
quaternions. I suspect that it's doable in GridFlow and less doable with
other plugins, as it is usually the case, but I don't know.
> This also calls for a method of summing the rotations when applying
> multiple times (and my current understanding is that this can only be
> done by multiplying the quaternion on each rotation)
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| Mathieu Bouchard - tél:+1.514.383.3801, Montréal, Québec
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