As far as i know congruent transforms are such 'preserving distance between
every two points of the transformed space' (yeah, sounds easy). In fact pure
rotation, translation and mirroring are congruent affine transformations,
while homothety (also known as scaling) is not. So, non-congruent transform
you could get with great ease: some sines, cosines and boo! I hate
trigonometry. Possible workaround: define a net of correct positions around
the world and snap users' wishes to its nodes. Or recheck your matrix: there
may be a too obvious mistake - I bet you hate trigonometry too.
Good luck
>From: "Pondrom, Pierre L" <[EMAIL PROTECTED]>
>Reply-To: Discussion list for Java 3D API <[EMAIL PROTECTED]>
>To: [EMAIL PROTECTED]
>Subject: Re: [JAVA3D] non-congruent transform
>Date: Thu, 20 Apr 2000 08:23:48 -0500
>
>I have not heard of this either. I would look at the matrix for the
>Transformation. The entries on the principle diagonal should not
>be zero. Check the input to this matrix.
>
>
>
> > ----------
> > From: Kraemer, Max,
>CTR[SMTP:[EMAIL PROTECTED]]
> > Reply To: Discussion list for Java 3D API
> > Sent: Tuesday, April 18, 2000 3:57 PM
> > To: [EMAIL PROTECTED]
> > Subject: [JAVA3D] non-congruent transform
> >
> > I'm trying to display the earth and allow the user to snap the view
>about
> > the earth based on data selected by the user. However, I occasionally
>get
> > a
> > BadTransformException. According to the exception, the transform above
> > the
> > ViewPlatform is non-congruent. I have no idea what a non-congruent
> > transform is nor do I know what can cause a transform to become
> > non-congruent. Does anyone know what can cause this to happen?
> >
> > Max Kraemer
> > [EMAIL PROTECTED]
> > (719) 567-0869
> >
> >
>==========================================================================
> > =
> > To unsubscribe, send email to [EMAIL PROTECTED] and include in the
> > body
> > of the message "signoff JAVA3D-INTEREST". For general help, send email
>to
> > [EMAIL PROTECTED] and include in the body of the message "help".
> >
>
>===========================================================================
>To unsubscribe, send email to [EMAIL PROTECTED] and include in the body
>of the message "signoff JAVA3D-INTEREST". For general help, send email to
>[EMAIL PROTECTED] and include in the body of the message "help".
________________________________________________________________________
Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com
===========================================================================
To unsubscribe, send email to [EMAIL PROTECTED] and include in the body
of the message "signoff JAVA3D-INTEREST". For general help, send email to
[EMAIL PROTECTED] and include in the body of the message "help".
