Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!n8emr!uncle!oink!jep
From: jep@oink.UUCP (James E. Prior)
Newsgroups: comp.graphics
Subject: Re: Ray Traced Bounding Spheres
Message-ID: <23@oink.UUCP>
Date: 16 May 89 13:54:07 GMT
References: <17241@versatc.UUCP> <17249@versatc.UUCP> <8411@phoenix.Princeton.EDU> <SARREL.89May14223947@galley.cis.ohio-state.edu> <12851@umn-cs.CS.UMN.EDU>
Reply-To: jep@oink.UUCP (James E. Prior)
Distribution: usa
Organization: Random Prime Research Institute  Columbus, Ohio
Lines: 13

In article <12851@umn-cs.CS.UMN.EDU> ken@uf.msc.umn.edu (Kenneth Chin-Purcell) writes:
...
>Since in general it takes 4 points to define a sphere, my
>intuition leads me to think that the true general solution will
>involve 4 bounding points.

You are correct in that a general solution requires 4 points, but we
aren't faced with a general problem.  We are faced with a special one,
one that needs the smallest sphere.  The requirement of the smallest 
sphere is information itself.  Enough so that one doesn't need 4 points
to define the sphere.  
-- 
Jim Prior    jep@oink    osu-cis!n8emr!oink!jep    N8KSM