POV-Ray : Newsgroups : povray.newusers : Transparent Objects Become Black : Re: Transparent Objects Become Black Server Time
9 Dec 2021 09:53:24 EST (-0500)
  Re: Transparent Objects Become Black  
From: Thomas de Groot
Date: 16 Nov 2021 07:57:47
Message: <6193aacb$1@news.povray.org>
Op 16-11-2021 om 11:52 schreef Mr:
> Thomas de Groot <tho### [at] degrootorg> wrote:
>> Op 11-11-2021 om 19:19 schreef bubble_person:
>>> Finally, with the fade_power, how is 1000 bad, but 1 or 1001 good?  I did a
>>> little copy-pasting of this part from an example, so I had not really asked
>>> myself what realistic values should be.
>>>
>> Alain is right about the fade_power of 1001. However, when I wanted to
>> find again the location of this in the wiki pages to help your
>> understanding of it - surprisingly - I was unable to find it! I am sure
>> it was there, somewhere, in the documentation...
>>
>> --
>> Thomas
> 
> Generally, when this occurs, the bit of information, is rather in release logs
> instead of doc, if you do find it in one or the other, please share, so that we
> can update or ignore. Meanwhile, I added some of Alain's guidelines to
> dispersion page in the wiki which are developing a bit further than current doc,
> so if a native speaker wants to restyle, do not hesitate and add your
> improvements in the page's discussion:
> https://wiki.povray.org/content/Reference:Interior#Dispersion
> 
I am not sure. In the 'Attenuation' section of 'Dispersion & Caustics', 
there is that mention about "If you set fade_power in the interior of an 
object at 1000 or above, a realistic exponential attenuation function 
will be used". I guess that the '1001' value comes from there.

This brings the following question: What is the difference between 
fade_power 2 and fade_power 1001, as both, in the docs/wiki, are 
described as 'exponential'?

Finally, in:
https://news.povray.org/povray.binaries.images/thread/%3C4f2654d6%241%40news.povray.org%3E/

Ive tells us: "note that this "fade_power 1001" statement is an old (and 
really dirty as it lacks any logic) hack that is part of POV-Ray since 
ages to turn realistic fade power calculation on."

Food for thoughts?

-- 
Thomas


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