Quaternions (was Re: [SDL] moving foward in 3d with x y and z rotation)

Oliver Batchelor shadows at ihug.co.nz
Sat Apr 1 03:17:55 PST 2000


yea but how can you then "get" the matrix that it makes ?
I can apply the glRotate stuff to vertices etc... but how to "take" the values
out..

thanks
Oliver

On Sat, 01 Apr 2000, you wrote:
> yes it does, in particular
> glRotate*(angle,x,y,z) where angle is the angle of counterclockwise
> rotation in degrees, and x,y,z, are the endpoint of the vector.
> glTranslate*(x,y,z) where x,y,z are the values to move along that
> particualr axis.
> 
> You may want to take a short trip to www.opengl.org and read a few of
> the tutorials they have there.
> 
> 
> --- Oliver Batchelor <shadows at ihug.co.nz> wrote:
> > does opengl do this ?
> > Or should I just make up my own matrix and use that ...
> > 
> > 
> > On Sat, 01 Apr 2000, you wrote:
> > > Yes, via the use of a transformation then a rotation.
> > > 
> > >    The transformation of course to move each point, and the
> > roatation
> > > to turn the point.
> > > 
> > > --- Oliver Batchelor <shadows at ihug.co.nz> wrote:
> > > > I just read that article on gam***a  and Im 350 % confused.
> > > > Are you sure that this cant successfully be done in something
> > much
> > > > simpler like
> > > > matrices   ?
> > > > 
> > > >   I dont know much about them either but at least they seem 
> > > > understandable .. because quaternions are way out of my depth in
> > math
> > > > knowledge
> > > > ...
> > > > 
> > > > Oliver
> > > 
> > > 
> > > =====
> > > Jason Platt.
> > > 
> > >    "In theory: theory and practice are the same.
> > >     In practice: they arn't."
> > > 
> > > ICQ# 1546328
> > > 
> > > __________________________________________________
> > > Do You Yahoo!?
> > > Talk to your friends online with Yahoo! Messenger.
> > > http://im.yahoo.com
> > 
> 
> =====
> Jason Platt.
> 
>    "In theory: theory and practice are the same.
>     In practice: they arn't."
> 
> ICQ# 1546328
> 
> __________________________________________________
> Do You Yahoo!?
> Talk to your friends online with Yahoo! Messenger.
> http://im.yahoo.com



More information about the SDL mailing list