POV-Ray : Newsgroups : povray.binaries.images : 'solid media' human model : Re: 'solid media' human model Server Time
28 Sep 2022 11:42:42 EDT (-0400)
  Re: 'solid media' human model  
From: Kenneth
Date: 18 Apr 2022 22:05:00
Message: <web.625e17d0d1523eea4cef624e6e066e29@news.povray.org>
MichaelJF <fri### [at] t-onlinede> wrote:

> One of the best Standford Bunnies I ever noticed so far. Very nice! I
> think it would look better with a more "natural" background.

Thanks. I was kind of 'quick and dirty' with these renders-- I was working on
something else media-related, and got sidetracked. ;-)  The cross-hatched
background is a specific one I use to test how 'solid' the media is; if I can
see the pattern, then the media isn't solid enough!
>
> The problem with this approach is that media have no surface. With some
> efforts one can color them but one has no finish and one cannot use
> features depending on a finish-statement.
>

That's true; the method does have its limitations. And scattering media itself
has a basic limitation, IMO: The 'extinction' value cannot use its own color
vector. So the extinguished parts of the media (the shadows with itself) are
always the complementary color, particularly if the media is very dense. Of
course, that's the correct paradigm for the filtering effect of the media, but
it's a 'creative' bottleneck. If extinction could use a color vector, it would
be easy to do something like...

     scattering{ 1, <0.3,0.6,0.9> extinction (1 - <0.3,0.6,0.9>)

to get 'all one color' throughout. That's why I usually use emission +
absorption medias for such 'solid' renders, rather than scattering-- which makes
it easy to give the absorbing media the complementary color. And it's faster to
render!


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