Undocumented features of commit 54b283a

[wfpokorny]

Opening this issue so we at some point resolve whether these features stick around in the code base or not - and if so we document them. Ref commit: 54b283a. See too this newsgroup post:

http://news.povray.org/povray.beta-test/thread/%3C57c84edf%241%40news.povray.org%3E/

Features:

• Radiosity support for brilliance.
• The brilliance effect can now be applied not only to incoming light, but also to outgoing light.
• Fresnel angle-dependent attenuation can now also be enabled for highlights and the diffuse component

...

[wfpokorny]

The two parameter brilliance mentioned above has been disabled by commit 1968b7d on December 13, 2016.

Additional newsgroup commentary:

http://news.povray.org/povray.documentation.inbuilt/message/%3C584fc229%241%40news.povray.org%3E/#%3C584fc229%241%40news.povray.org%3E

[wfpokorny]

Status ahead of 3.7.1 release for the three original features listed as of Feb 16, 2017:

• Radiosity support for brilliance remains in the code, but is not documented at: http://wiki.povray.org/content/Reference:Radiosity

• The two term brilliance effect has been pulled from the code as noted previously.

• The Fresnel angle-dependent attenuation is now documented.

[c-lipka]

I see no reason to pull the brilliance on|off switch out of v3.8; however, we should document it properly before doing the v3.8.0 release.