Ron Parker wrote:

> >  There is a major difference between the two. The union is really not
> >a true CSG operation and could be more accurately described as a group
> >container.
> 
> Interesting distinction you make there.  I'd say union is the true
> CSG operation - since it's what we'd generally consider atomic - and
> merge is the imposter; it's able to be synthesized by clever
> combination of intersection and inverse.

  Since I was responding to a question in the new users group I defend my
reply as appropriate for conveying a new concept. Had he asked for info
on and, or, and not operations I probably would have remained silent and
would have let you answer it yourself.

  I like to think of CSG operations as to how they perform physically in
an operation. My idea of more better analogies would be:

union        = gluing
intersection = cutting
difference   = scooping
merge        = melting and gluing
clipping     = cutting and hollowing
inverse      = inside outing

There ! That should give you something to cry in despair over for a while :)

-- 
Ken Tyler

See my 1000+ Povray and 3D Rendering and Raytracing Links at:
http://home.pacbell.net/tylereng/index.html

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