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From: bos_m@sun005.research.ptt.nl (Marnix van den Bos)
Subject: Re: Let there be light
Message-ID: <1994May31.134109.23732@news.research.ptt.nl>
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References: <1994May31.080926.15254@news.research.ptt.nl> <2sf2s5$ipf@lyra.csx.cam.ac.uk>
Date: Tue, 31 May 1994 13:41:09 GMT
Lines: 28

In article <2sf2s5$ipf@lyra.csx.cam.ac.uk>,
Gareth Rees <gdr11@cl.cam.ac.uk> wrote:
>Marnix van den Bos writes:
>> I have a question about light sources: How do I determine whether or not
>> there is (indirect) light in a location or object?
>
  [algorithm and remarks deleted]
>-- 
>Gareth Rees
>
>
In my opinion, I still have a problem here, Gareth. Namely with the 
position of the viewer. I think an object can be in light according to
your algorithm, with the character not being able to see it. Suppose
I am in a closed box and outside the box is an object. Both box and
object are in a location which is lit. I will not be able to see the 
object, although IsLit(object) will return true. Now, if someone else
enters the location, he will be able to see the object. I think what I
am really looking for is a function like IsVisibleTo(object, viewer), 
that tells me whether viewer is able to see object. If I misinterpreted
your algorithm, please let me know.

Marnix.

C
I have a  


