[Papervision3D] Quaternions vs matrix
acorcutt at gmail.com
Tue Jan 16 12:46:41 EST 2007
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.
On 1/16/07, Carlos Ulloa <c4rl054321 at gmail.com> wrote:
> 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
> // 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
> > Is there a reason why PV3d uses matrix and not quaternions? I am new to
> > this so just looking for some guidance.
> > Randy Howk
> > 212.846.6905
> > randy.howk at mtvnmix.com
> > _______________________________________________
> > Papervision3D mailing list
> > Papervision3D at osflash.org
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> Papervision3D at osflash.org
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