POV-Ray : Newsgroups : povray.newusers : 2 problems : Re: 2 problems Server Time
2 Nov 2024 17:19:59 EDT (-0400)
  Re: 2 problems  
From: Justin Smith
Date: 1 Nov 2003 20:45:01
Message: <web.3fa45ec67933238264ba676d0@news.povray.org>
Christopher James Huff wrote:
>In article <web.3fa31f44e63905fc30a67eb20[at]news.povray.org>,
> "Justin Smith" <t74### [at] yahoocom> wrote:
>
>> I have this landscape I'm working on. I'm trying to use media to generate a
>> blue sky. Basically, it is a scattering media of type 4, and the color it
>> scatters is <.2,.2,.0001>*.0005. This gets me the blue sky I want. However,
>> all the objects in the scene turn blue. I have some white snow that
>> especially turns blue, almost the same blue as the sky. I have tried
>> setting ambient to 1 with radiosity turned on, but it still comes up blue.
>
>You don't show the code for the media you're using. Anyway, the solution
>is simple: make the media less dense, and make the sky container bigger
>to compensate.

Thanks. Actually, I decided for now to go with just enclosing the scene in a
giant blue sphere, but I still want to use media for general air thickness
so that distant objects look faded. Here is my current media block:

box
{
  <-5000,0,-5000>,<5000,800,5000>
  texture
  {
    pigment
    {
      color rgbt <1,1,1,1>
    }
  }
  interior
  {
    media
    {
      method 3
      samples 4
      intervals 1
      scattering
      {
        4,
        color rgb <1,1,1>*.00075
        extinction 1
      }
    }
  }
  hollow
}

The air thickness looks about right, but I've noticed that objects casting
shadows don't seem to be casting shadows through the air itself as I've
seen in other scenes with media. Is there anything special I have to turn
on that I've forgotten? There is a keyword "media_attenuation" that goes in
the light_source but I'm not really sure if that is it, and since it
currently takes about 6 hours to render this image with media, I think it
would be quicker to ask here.


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