On 26 Feb 2000 13:14:43 -0500, Nieminen Juha
<war### [at] sarakerttunencstutfi> wrote:

>  There are three similar things: Bounding, clipping and the intersection CSG.
>They functions are, however, very different and should not be confused.
>  What you are talking about, actually, is this:
>
>  intersection
>  { object { MyObject }
>    object { BoundingObject }
>    bounded_by { BoundingObject }
>  }
>
>  Since it can be done, and it's very intuitive, it should not be changed.
>It should, however, be documented better.
>  For some reason I have never had any confusion about these three things.

I have not either. Perhaps you have missed my main point, and it is
textures. Imagine you have this:

intersection
{ union
  { sphere { -x, 1 pigment { Red } }
    sphere { x, 1 pigment { Blue } }
  }
  box { <-3,0,-2>, <3,2,2> }
}

Now, there is no simple way to make the surfaces of the spheres that
show up after being chopped off preserve their texture. They get the
texture of the box, which in this example is default or black. If
this:

union
{ sphere { -x, 1 pigment { Red } }
  sphere { x, 1 pigment { Blue } }
  bounded_by { box { <-3,0,-2>, <3,2,2> } }
}

worked in the desired way it would make certain tasks easier. Either
that, or the way CSG works could be modified for the purpose.


Peter Popov
pet### [at] usanet
ICQ: 15002700

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