Ken wrote in message <365### [at] pacbellnet>...
>Take a close look at the box statement below.
>
>box{<-1.0, 1.0, -1.0>,< -1.0, -1.0, -1.0>}
>
>This will render with out error in v3.1a. Why ? I would think
>a divide by zero error of something would happen. I know a
>scale <0,1,0> will yeild a warning and Pov will automaticaly
>add a scale by 1 in the 0 vectors BUT if built with a 0 demension
>it is unaware ?
>Given a zero demnsion in the x and z directions what is
>it rendering. An infininatly thin y axis box ?
>
>Ken Tyler
>
As far as I can tell, it's because it's not scaling it. The XYZ coords are
valid, as far as Pov is concerned, because it builds to those dimensions.

Also, a scale <0,1,0> doesn't scale an object down to 0. Look at how scale
works.. It's a percentage. think "scale by X" instead of "scale to X".
the way the math works (forgive me if I'm wrong.. i'm rusty..) is thus:

Scale <0,1,0> = vector.x / (1/scale.x) , vector.y / (1/scale.y) , vector.z /
(1/scale.z)
hence the division by 0 errors.

(No idea why it doesn't use multiplication... it would be easier, and have
no problem with a 0 value.... )

--
Twyst
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