POV-Ray : Newsgroups : povray.newusers : Media in Povray 3.5 : Re: Media in Povray 3.5 Server Time
31 Jul 2024 02:25:32 EDT (-0400)
  Re: Media in Povray 3.5  
From: Tim Nikias
Date: 14 Feb 2003 08:09:23
Message: <3e4cea83$1@news.povray.org>
> 1. Test the 'shape' of your media-density using emitting media - much faster
> than scattering

True

> 2. Unlike most aspects of POV, media is very sensitive to scale, but in general
> the media colour/density will need to be a lot less than <1,1,1>. To get the
> same thickness of media at different scales, divide the media colour by the new
> scale.*

I'll come back to that later...

> 3. Use the defaults to start with.

True

> 4. Always try and use a container

True

> 5. Oh, and don't use rgbft 1 for your container's pigment - either rgbf 1 or
> rgbt 1

I'm curious, why? I'm always using rgbt...

Now to that color...
I've come across a very nice method to model clouds etc (almost
any subsurface-scattering) with using rather high scattering values,
some high absorption values being the inverse of the scattering-color
(<1,1,1>-Scattering_Color) and then some high density values
(no color here, just rgb 5 or something), and get nice results. Playing
a little with the different values (once you know better what they're
supposed to do) gives you all kind of nice side-effects, which you can
either aim for or leave away.
The clouds in the Worldbowl of my ongoing project for 2003 are
made that way, they even use emission for some coloring...
If its only for a small effect, yes, low rgb-colors are needed, but if
you really want to make something "feel" solid, and still don't want
a bright patch of white, thats the approach I'm using since I've discovered
it.
(In case someone tries to download the Worldbowl-Sources on my
homepage: thats the old version, using stacked-planes for the clouds,
no media)

Regards,
Tim

--
Tim Nikias
Homepage: http://www.digitaltwilight.de/no_lights/index.html
Email: Tim### [at] gmxde

>
> <snip>
>
> Someone, someday, will write the definitive media tutorial, but I don't think
> it's there yet.
>
> Some general tips.
>
> 1. Test the 'shape' of your media-density using emitting media - much faster
> than scattering
> 2. Unlike most aspects of POV, media is very sensitive to scale, but in general
> the media colour/density will need to be a lot less than <1,1,1>. To get the
> same thickness of media at different scales, divide the media colour by the new
> scale.*
> 3. Use the defaults to start with.
> 4. Always try and use a container
> 5. Oh, and don't use rgbft 1 for your container's pigment - either rgbf 1 or
> rgbt 1
>


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