[Papervision3D] Quaternions vs matrix

[Anthony Corcutt]

Hi, the old strobe3d engine  I uploaded yesterday (under the 'old
engine' post) uses matrix math - its using a proper 4D matrix, with
hierarchical children etc..

Matrix math will be a lot faster in the long run (& less calculations
like you said) when you have quite a few faces, objects & hierarchy,
plus it helps out with the lighting & clipping (I never got that far).

I did look at quaternions first (I think one of the old flash examples
uses this), but I knew a lot of the matrix math so went with that.
Quaternions is harder maths and I could not figure how to get them to
multiply down the hierarchy like the matrices.

Anthony


On 1/16/07, Carlos Ulloa <c4rl054321 at gmail.com> wrote:
> Hey,
>
> Currently Papervision3D doesn't use matrix nor quaternion math.
>
> Due to its humble beginning, a cheap and fast solution based on the cosine
> law was chosen. At the time, Paper was Flash 7 and it seemed more than
> enough for the purpose. Unfortunately this approach has a lot of limitations
> and contrary to what I believed it actually requires more calculations.
>
> As anyone with some math background might have noticed, Papervision had a
> very weak math. Fortunately, for the next revision all the 3D code has been
> rewritten to use 3x4 matrices. This will enable transformation hierarchy and
> complex scene import.
>
> I believe quaternions are slightly slower due to the increased number of
> values. But they have two unique advantages, no gimbal lock and easier
> rotation interpolation. So they probably come in at some point.
>
>  As jake said, all changes (particularly those that involve more advanced
> technology) had to be very carefully evaluated so performance doesn't
> suffer.
>
> C4RL05
> // noventaynueve.com
> // papervision3d.org
>
>
>
> On 16/01/07, Randy Howk <Randy.Howk at mtvnmix.com > wrote:
> > I ran across this article doing research for my own 3d engine to make an
> > interactive 3D UI. What are the benefits of using quaternion math vs
> matrix?
> > Is  there a reason why PV3d uses matrix and not quaternions? I am new to
> > this so just looking for some guidance.
> >
> >
> http://www.adobe.com/devnet/flash/articles/3d_classes.html
> >
> >
> > Randy Howk
> > 212.846.6905
> > randy.howk at mtvnmix.com
> >
> >
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> >
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> >
>
>
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