"Warp" <war### [at] tagpovrayorg> wrote in message
news:3b850c65@news.povray.org...
> Ben Chambers <bdc### [at] hotmailcom> wrote:
> : However, experimentation shows that the four corners are actually
> : P-U-V, P+U-V
> : P-U+V, P+U+V
> : With the center of the rectangle (more or less :) being located at P.
>
> : And so, two sides would have a length of 2*|U| and the other two would
have
> : 2*|V|.
>
>   Wrong. The corners are located at
>
> P-U/2-V/2, P+U/2-V/2
> P-U/2+V/2, P+U/2+V/2
>
> and the length of the sides is U and V.

Thanks, this makes sense.  It was easier to see that P was the midpoint than
to see exactly how far out the lights went.  Maybe the docs could explain
this better in 3.5?  (Or maybe not, I don't know how much still has to be
done...)

...Chambers

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