Hello Kevin,
Isn't that a bit counter intuitive? Normally, in the world of math, when
people talk about normalizing a vector, matrix, or other tensor (call it
T), they mean that they adjust it such that |T|=1, where |T| is a norm,
usually the L2 (euclidian) norm. In general this is done by setting
T=T/|T|. Thus, in a trasform3D, I would expect that "normalize" would
change the determinant to 1. Of course, this can be done even if the
element of the bottom left corner (the scaling one) is not equal to 1, as
long as the rotational and translational components are appropriately
adjusted.
In any case, the term "normalize" doesn't seem correct for this type of
error correction that you mention. Am I missing something here?
Paraskevas
--- Kevin Rushforth <[EMAIL PROTECTED]> wrote:
> No, the normalize methods ensure that the column vectors are orthogonal
> to each other. It does not alter the scale. (Earlier versions
> of Java 3D had a bug that would force the scale to 1.0, but that was
> never the intent). The main use of these methods is to correct for
> floating point errors that accumulate over time when concatenating
> a large number of rotation matrices.
>
> --
> Kevin Rushforth
> Java 3D Team
> Sun Microsystems
>
> [EMAIL PROTECTED]
>
>
> >Date: Tue, 20 Mar 2001 10:34:57 -0600
> >From: "Andrew R. Thomas-Cramer" <[EMAIL PROTECTED]>
> >Subject: [JAVA3D] Transform.normalize -- what does it do?
> >To: [EMAIL PROTECTED]
> >
> >
> >The class javax.media.j3d.Transform has methods normalize() and
> normalizeCP() that "normalizes the rotational components (upper 3x3)" of
> the transform. Pardon my ignorance, but what exactly does that mean? Is
> that another way of saying that these methods replace the scaling
> component with uniform scale factor = 1?
> >
> >-----------------------------------------------------------------------
> >Andrew R. Thomas-Cramer
> >Work: [EMAIL PROTECTED] http://www.prism-cs.com/
> >Home: [EMAIL PROTECTED] http://www.execpc.com/~artc/
> >-----------------------------------------------------------------------
>
>
===========================================================================
> 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".
__________________________________________________
Do You Yahoo!?
Get email at your own domain with Yahoo! Mail.
http://personal.mail.yahoo.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".
