RE: [Algorithms] Determining Whether an Orientation Has Changed

[Ian E. <ie...@ku...>]

Just be sure that the assumption is valid that there are not rotations
close to or more than 360d. 

-----Original Message-----
From: gda...@li...
[mailto:gda...@li...] On Behalf Of Andy
Luedke (Volt)
Sent: Monday, December 16, 2002 2:47 PM
To: gda...@li...
Subject: RE: [Algorithms] Determining Whether an Orientation Has Changed

The direction vector doesn't encapsulate the entire rotation of the
object.  The forward vector could be near-equal, but the other two basis
vectors of the 3x3 matrix may be vastly different.  Assuming you have a
fully orthonormal rotation matrix, you could do a dot product of two of
the basis vectors to determine if the orientation is similar.


-----Original Message-----
From: Pierre Terdiman [mailto:p.t...@wa...] 
Sent: Monday, December 16, 2002 2:34 PM
To: gda...@li...
Subject: Re: [Algorithms] Determining Whether an Orientation Has Changed

> I have two orientations of a particular object, one for this frame and
> one from last frame. The orientations are represented by quaternions,
> but they could just as easily be 3x3 matrices. I also know the time
> between the frames.
> 
> What I'd like to find out is whether the orientation has changed by
more
> than a small amount. I could extract the Euler angles and compare
each,
> but I was hoping to find a faster solution. The solution could be
> approximate, but must work for various delta times.

You can simply use the dot product between the two direction vectors.

P.



-------------------------------------------------------
This sf.net email is sponsored by:
With Great Power, Comes Great Responsibility 
Learn to use your power at OSDN's High Performance Computing Channel
http://hpc.devchannel.org/
_______________________________________________
GDAlgorithms-list mailing list
GDA...@li...
https://lists.sourceforge.net/lists/listinfo/gdalgorithms-list
Archives:
http://sourceforge.net/mailarchive/forum.php?forum_id=6188


-------------------------------------------------------
This sf.net email is sponsored by:
With Great Power, Comes Great Responsibility 
Learn to use your power at OSDN's High Performance Computing Channel
http://hpc.devchannel.org/
_______________________________________________
GDAlgorithms-list mailing list
GDA...@li...
https://lists.sourceforge.net/lists/listinfo/gdalgorithms-list
Archives:
http://sourceforge.net/mailarchive/forum.php?forum_ida88