Peter Popov wrote:
> 
> On Sat, 04 Sep 1999 06:57:15 -0700, Ken <tyl### [at] pacbellnet> wrote:
> 
> >Notice how there is no scale given in the box's y direction ?
> 
> The things one learn every day... I think though that this is
> internally converted to a unit box with the appropriate transformation
> matrix applied, and since POV changes a zero scale to unity scale, you
> might as well replace the zeroes with ones there as there's no
> difference between them. There, I beat the bejesus out of boolean
> algebra :)

The proof comes from rendering the following:

camera{location z*-3.5 look_at 0 }
light_source { z*-13 rgb 1}
background{rgb .55}

box { <-1,0,-1>, <1,0,1> pigment{red 1}}

All that you will see once rendered is a thin red line. I found this about
9 months ago and it was discussed for a while and dropped as to why Pov
allows this. The important thing is that it does work. In fact it you attempt
to use it like a triangle in a CSG operation it suffers the same limitations
as a triangle or other similar infinitely thin Pov primitives.

> I regret to say this, but you are wrong. You can use manual *and*
> automatic bounding simultaneously. You just have to tell POV to keep
> the user bounds, because by default it will remove them. The command
> line option is -UR and the INI file setting is Remove_Bounds=off. In
> case you are bounding a union you might have to have Split_Unions=off
> or use -SU in the command line.
> 
> Peter Popov
> ICQ: 15002700

I was not wrong I simply did not offer all of the possible solutions that
you did :)

-- 
Ken Tyler

See my 850+ Povray and 3D Rendering and Raytracing Links at:
http://home.pacbell.net/tylereng/index.html

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