POV-Ray : Newsgroups : povray.binaries.images : Scattering media with a color_map - how to do? : Re: Scattering media with a color_map - how to do? Server Time
4 Nov 2024 19:22:19 EST (-0500)
  Re: Scattering media with a color_map - how to do?  
From: Jörg 'Yadgar' Bleimann
Date: 23 Nov 2009 03:36:53
Message: <4b0a49a5$1@news.povray.org>
High!


> Personaly, I'd start by removing the emissive media, or tone it down a 
> lot. No more than emission 0.001.
> 
> Next, use scattering type 5 with a negative exentricity for the outer 
> rings: most of the incoming light is scattered back. Use a second media 
> with type 2 or 3 for the inner ring, also, with a much lower density.
> 
> Not sure about your use of a filtering component in your color_map.
> 
> You scale the rings by 10 000. That means that there is 10 000 times 
> more media. The thickness of the ring goes from 0.002 to 20. Then, with 
> your very oblique view, you probably travel at least 5 times longer 
> through the media. This may explain, toggether with your emissive media, 
> why you get that saturated white ring.

Meanwhile, I tried this with my original Saturn scene (see my second 
posting in this thread)... but then, a new problem occurs: as the 
original color and transparency maps consist of 1500 values each, I had 
to compose the original color_map from six single color_map put together 
in one texture_map (a color_map can only contain up to 255 entries).

As I now reworked the whole thing as a media statement, I got the error 
message "Keyword 'texture_map' can only be used in a texture statement."
How can I still build multi-partite color_maps? Or do I have to reduce 
the entries to 255?

See you in Khyberspace!

Yadgar


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