Chris Huff wrote:
> 
> If you are using MegaPOV, it would be much easier to use:
> 
> transform {matrix <...> inverse}
> 
> This is even more useful, since you can specify any series of
> transforms, and use declared transforms...however, it can't be used to
> get the matrix, as your macro can be modified to do.
> 
> Or maybe it can...it should be possible by using vtransform() to
> "scan" a matrix, using x, y, and z to get the first 3 columns, and
> < 0, 0, 0> to get the fourth...right?

First you would use vtransform on <0,0,0> to get the translation
component (call it, say vL); then you use vtransform on x, y and
z, separately, and subtract vL from the results of each.

> > If you want to understand this sort of thing better (useful
> > for things outside of POV-Ray, too!), go find "matrix inversion"
> > and "matrix multiplication" on the Web, and find a page that
> > makes sense to you.
> 
> www.google.com is very helpful here...

Google is helpful no matter *what* you're looking for...

> For POV-specific pages, try the
> links page on povray.org, but the ones I've found don't explain
> inversion and stuff, just how to use the matrix transform.

True.

Regards,
John
-- 
ICQ: 46085459

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