RE: [boost] Re: Interest for quaternions (and octonions)?

From: Reid Sweatman (borderland_at_[hidden])
Date: 2001-01-01 06:32:36

Same problem we need to solve in games.  Is it possible (assuming you don't
end up licensing it) to generalize the mechanism handling your orientation
constraints?  That would really be useful.

Reid Sweatman
Software Engineer

> -----Original Message-----
> From: Hubert.Holin_at_[hidden] [mailto:Hubert.Holin_at_[hidden]]
> Sent: Thursday, December 21, 2000 3:26 PM
> To: boost_at_[hidden]
> Subject: [boost] Re: Interest for quaternions (and octonions)?
>
>
> Paris (U.E.), le 21/12/2000
>
> 	Actually, the file I uploaded is one end product of soome work I
> did with a colleague about orientation interpolation (quaternions are
> superior to Euler angles, among other reasons because they are not
> succeptible to "gimbal lock", which is a degeneracy in the
> representation for special values of the orientation).
>
> 	The problem we solved (though this is *not* included in the public
> file), is that of orientation under constraint, i.e. if we want to
> emulate a real film camera, the "up" must not "wobble" between
> keyframes. I tried to licence that part, so far with no result :-<  .
>
> 	One thing which *is* in that file is the exponential of the
> quaternions, which I believe, is a result which I invented (more
> precisely, the closed formula giving the result is my invention, not
> the existence of the exponential (of one stripe or another) on the
> quaternions...). This can be used to achieve interpolation of
> orientations (in 3d-space), but with the "woble"...
>
> 	A last note: I have some ideas about cryptography and quaternions,
> but the implementation I proposed is not the best suited to this
> problem.
>
> 		Hubert Holin
> 		Hubert.Holin_at_[hidden]
>
> --- In boost_at_[hidden], Lutz Kettner <kettner_at_i...> wrote:
> > Hi,
> >
> > there is interest in the graphics community for quaternions as
> > a _good_ representation of 3d rotations and for the ArcBall user
> > interface interaction technique for rotations. They are also very
> > nice for interpolating between two different orienations of a
> > 3d object. I don't know about numerics and quaternions.
> >
> > Lutz Kettner
> >
> > ----------------------------------------------------------------------
> > UNC Computer Science                       email: kettner_at_c...
> > CB 3175, Sitterson Hall                    phone: [phone] x7759
> > Chapel Hill, NC 27599-3175, USA            fax:   [phone]
> > ---------------------------------------------------------------------
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