On 25 Oct 2000 07:59:36 -0400, Warp wrote:
>  I described extensively what I call "the shadow line artifact" in the VFAQ.
>  Direct URL:
>
>http://iki.fi/warp/povVFAQ/TheShadowLineArtifact/

Another problem with your proposed solution is the problem of non-convex
objects.  The "first intersection belongs to the object" criterion should
instead read "the ray intersects the object an odd number of times."

That works for light sources outside the object.  Flip it to "even" if
the light source is inside the object.  It could also lead to crand-like 
graininess on some shadow lines, though, due to imprecision.  That's a 
harder problem to fix, but we've lived with it in lathes and prisms, right?

Another problem appears if your sphere contains (for example) another slightly
smaller sphere - the smaller sphere will shadow the larger one.


-- 
Ron Parker   http://www2.fwi.com/~parkerr/traces.html
My opinions.  Mine.  Not anyone else's.

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