Path: utzoo!utgpu!watmath!clyde!att!rutgers!mit-eddie!bloom-beacon!apple!well!ewhac
From: ewhac@well.UUCP (Leo 'Bols Ewhac' Schwab)
Newsgroups: comp.graphics
Subject: Village Idiot Asks About Raytracing
Message-ID: <7818@well.UUCP>
Date: 3 Dec 88 09:34:44 GMT
Reply-To: ewhac@well.UUCP (Leo 'Bols Ewhac' Schwab)
Organization: The International Beam-Wesley-Into-A-Bulkhead Society
Lines: 34
Quote: "Raffert was dying.  It's difficult to be neat under those
	circumstances."  -- Avon

[ #include  ]

	I was doing a few gedanken experiments with raytracing, and came up
with a few questions.  Realize that I've never written a raytracer.

	Suppose I have an object, a light source, and a flat surface set up
as a perfect mirror.  Suppose further that I have a thing between the object
and light source preventing direct illumination of the object.  Suppose
further still that the "mirror" is set up to reflect the light from the
light source to the object.  Question:  Will the object be illuminated?
Does it depend on whose software I'm using?

	Suppose I have a flat surface, a light source, and an object in the
shape of a convex lens above the surface under the light.  Suppose further
that the object is set up to be perfectly clear, and refracts light like
glass.  Question:  Will the light beneath the lens object be intensely
focused on the surface below, just like a real lens?

	The point of the above two questions is to find out if, in general,
raytracers handle illumination from light bounced off of or refracted
through other objects.

	Finally, has anyone come up with a raytracer whose refraction model
takes into account the varying indicies of refraction of different light
frequencies?  In other words, can I find a raytracer that, when looking
through a prism obliquely at a light source, will show me a rainbow?

	Something tells me that all three questions are rather hard.

_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_
Leo L. Schwab -- The Guy in The Cape	INET: well!ewhac@ucbvax.Berkeley.EDU
 \_ -_		Recumbent Bikes:	UUCP: pacbell > !{well,unicom}!ewhac
O----^o	      The Only Way To Fly.	      hplabs / (pronounced "AE-wack")
"Work FOR?  I don't work FOR anybody!  I'm just having fun."  -- The Doctor