POV-Ray : Newsgroups : povray.documentation.inbuilt : 6.7.3.2.2 Brilliance Server Time
28 Mar 2024 08:26:27 EDT (-0400)
  6.7.3.2.2 Brilliance (Message 1 to 2 of 2)  
From: Adrien Rebollo
Subject: 6.7.3.2.2 Brilliance
Date: 11 Nov 2002 17:38:51
Message: <pan.2002.11.11.22.37.12.806873@gmx.fr>
Hello,

I think the effect of brilliance is not very clearly documented :
it is written :
"Higher values from 5.0 to about 10.0 cause the light
to fall off less at medium to low angles"
However, looking at the source, and experimenting with the parameter,
I think it works the other way :
"Values higher than 1.0 cause the diffuse light to fall off more
sharply when the incident light is not perpendicular,
and becomes more tangent to the surface." or something like that.

But English is not my mother tongue, so it is possible I just
misunderstood 'fall off', and that my version does not make sense
at all.

Adrien Rebollo


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From: hughes, b 
Subject: Re: 6.7.3.2.2 Brilliance
Date: 11 Nov 2002 19:32:47
Message: <3dd04c2f@news.povray.org>
"Adrien Rebollo" <adr### [at] gmxfr> wrote in message
news:pan### [at] gmxfr...
>
> I think the effect of brilliance is not very clearly documented :
> it is written :
> "Higher values from 5.0 to about 10.0 cause the light
> to fall off less at medium to low angles"
> However, looking at the source, and experimenting with the parameter,
> I think it works the other way :
> "Values higher than 1.0 cause the diffuse light to fall off more
> sharply when the incident light is not perpendicular,
> and becomes more tangent to the surface." or something like that.
>
> But English is not my mother tongue, so it is possible I just
> misunderstood 'fall off', and that my version does not make sense
> at all.

I know English best and things like this can be confusing for me too.

I think you could be right, I can read that line two different ways. Depends
on what is meant by "low angles". Usually that would be like shallow angles
of incidence. Meaning the edges of a sphere, for example, rather than the
middle. In which case the wording is definitely wrong to say "less". But if
it were saying that low angles mean a direct object face to light source
orientation then it could be correctly worded. Either way, I have to agree
that it isn't clear enough in those words alone. To people new at this it
might not make sense even if worded as saying more rather than less and
shallow angles rather than low angles. Needs something added to the
description. Perhaps that edges facing away from a light will fall off more
quickly the higher brilliance is.


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