POV-Ray : Newsgroups : povray.documentation.inbuilt : Possible error in : Re: Possible error in Server Time
18 May 2022 03:01:03 EDT (-0400)
  Re: Possible error in  
From: Jim
Date: 20 Sep 2007 19:40:00
Message: <web.46f302b3f74215c291227f400@news.povray.org>
"Bent" <ben### [at] gmailcom> wrote:
> I think there's a typo in
> You should note two important facts: First, for Fade_Distance larger than
> one the light intensity at distances smaller than Fade_Distance actually
> increases. This is necessary to get the light source color if the distance
> traveled equals the Fade_Distance. Second, only light coming directly from
> light sources is attenuated. Reflected or refracted light is not attenuated
> by distance.
> The very first Fade_Distance should be Fade_Power, I believe.  Let me know
> if I'm incorrect, but it really doesn't make sense as is.
> Bent

The docs sound OK to me. According to my (probably somewhat limited)
understanding, that section means:

"If you set the Fade_Distance to something larger than one, the illumination
at distances less than that will increase."

Fade_Distance is sort of where the "sample" point is for determining how
bright a light is. If you sample at a given distance, the intensity will
already have decreased. Often in the non-POV world you'll see brightness
indicated as "x units, at 1 meter" - this is basically the same thing.

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