Re: [Plib-devel] Quaternions in plib

[Alexander R. <a_r...@in...>]

Hi,
> 
> Well, it appears it was my code that was broken - not plib.
> 
> This evening I took the tux on a pedestal example and adjusted it so you can
> fly around tux using quaternions, and it all works fine.  I nearly got
> carried away and changed it so you could fly tux about - but then I
> remembered it's susposed to be a simple example.
> 
> As it uses the tux data files should I place it in examples/src/tux or
> examples/src/quaternions and set the model and texture paths to ../tux/data?
> I prefer the later myself, but that's me.
> 
> If I get the time I'll write a small article to go with the exampe source.
> 
> Incidently why does sgCoord store euler angles?  Aren't eulers evil? :)  I
> would had expected an (x, y, z) vector and a quaternion.

a) DONT USE EULER ANGLES AT ALL!
b) use either direction vectors as I do, or quaternions, construct
   the transformation matrix yourself, BUT DONT USE EULER ANGLES!
c) you can calc direction vectors/quaternions to euler angles, that
   is safe, the other way round is 'unsafe'
d) It cost me a month , exactly this
e) have a look at the math help page on kobayashimaru.sourceforge.net
f) DONT USE EULER ANGLES!

I expect SpaceThing and KobayashiMaru very similar, have a look at
ssgUtil.cxx and spaceobject.cxx:PitchShip/MoveShip/setTransform

will give ypou the code you need.


Alex



-- 
                   Alexander Rawass
          Email: ale...@us...
   Project Homepage: http://kobayashimaru.sourceforge.net
...but some day you'll be a STAR in somebody else's SKY...