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Subject: Shadows according to LightSource type
Date: Mon, 14 Dec 92 16:03:39 -0800
From: Daryll Strauss <strauss@aero.org>


I read an article on one of the usenet groups about the correct way to
generate the zfile for shadows according to what LightSource you are
using. The posting indicated that distant lights should be rendered with
an orthographic projection. That makes sense since the light is
essentially parallel by definition of a distant light. (That should be
fixed for my "how to do shadows" posting.) It also mentioned that spot
lights should be rendered in perspective mode and that point sources
were really confusing. The perspective rendering for spots makes less
sense to me.  Can anyone explain why you'd do that? What's the
difficultly with point light sources?