Fog bounding objects.  I.e. fog only in this hollow cube.  Kinda like
media, but quicker, and without the scattering of light.

-- 
Tim Cook
http://empyrean.scifi-fantasy.com

-----BEGIN GEEK CODE BLOCK-----
Version: 3.12
GFA dpu- s: a?-- C++(++++) U P? L E--- W++(+++)>$
N++ o? K- w(+) O? M-(--) V? PS+(+++) PE(--) Y(--)
PGP-(--) t* 5++>+++++ X+ R* tv+ b++(+++) DI
D++(---) G(++) e*>++ h+ !r--- !y--
------END GEEK CODE BLOCK------

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"Timothy R. Cook" wrote:
> Fog bounding objects.  I.e. fog only in this hollow cube.  Kinda like
> media, but quicker, and without the scattering of light.

Also ...why is this message in some old thread?

-- 
Tim Cook
http://empyrean.scifi-fantasy.com

-----BEGIN GEEK CODE BLOCK-----
Version: 3.12
GFA dpu- s: a?-- C++(++++) U P? L E--- W++(+++)>$
N++ o? K- w(+) O? M-(--) V? PS+(+++) PE(--) Y(--)
PGP-(--) t* 5++>+++++ X+ R* tv+ b++(+++) DI
D++(---) G(++) e*>++ h+ !r--- !y--
------END GEEK CODE BLOCK------

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Timothy R. Cook wrote:

> "Timothy R. Cook" wrote:
>> Fog bounding objects.  I.e. fog only in this hollow cube.  Kinda like
>> media, but quicker, and without the scattering of light.

You mean like this:

#include "colors.inc"

  camera {
    location  <-20, 20, -20>
    look_at <20,20,20>
  }
  
  background { color SkyBlue }
  
  plane { y, -10
    pigment {
      checker color Yellow color Green
      scale 20
    }
  }
  
  box { <0, 0, 0>, <40,40,40>
    pigment { Clear }
    inverse
  }
  
  sphere { <-100, 150, 200>,  20
    pigment { Green }
    finish { phong 1.0 phong_size 20 }
  }
  sphere { <100, 25, 100>, 30
    pigment { Blue }
    finish { phong 1.0 phong_size 20 }
  }
  light_source { <100, 120, 40> color White}
  fog {
    distance 25
    color rgb 0.6
  }


> 
> Also ...why is this message in some old thread?
> 

It show up correctly here, so it might be your news reader.

- Micha

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On Mon, 04 Mar 2002 15:52:38 -0500, Timothy R. Cook wrote:
> "Timothy R. Cook" wrote:
>> Fog bounding objects.  I.e. fog only in this hollow cube.  Kinda like
>> media, but quicker, and without the scattering of light.

How does the current fade_* stuff not meet your needs?

> Also ...why is this message in some old thread?

Because your newsreader is broken.

-- 
#macro R(L P)sphere{L F}cylinder{L P F}#end#macro P(V)merge{R(z+a z)R(-z a-z)R(a
-z-z-z a+z)torus{1F clipped_by{plane{a 0}}}translate V}#end#macro Z(a F T)merge{
P(z+a)P(z-a)R(-z-z-x a)pigment{rgbt 1}hollow interior{media{emission T}}finish{
reflection.1}}#end Z(-x-x.2y)Z(-x-x.4x)camera{location z*-10rotate x*90}

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Ron Parker wrote:
> How does the current fade_* stuff not meet your needs?

I'm using ground_fog, and it's infinite along the plane which
it occupies.  Not useful for fish tanks or similar.

-- 
Tim Cook
http://empyrean.scifi-fantasy.com

-----BEGIN GEEK CODE BLOCK-----
Version: 3.12
GFA dpu- s: a?-- C++(++++) U P? L E--- W++(+++)>$
N++ o? K- w(+) O? M-(--) V? PS+(+++) PE(--) Y(--)
PGP-(--) t* 5++>+++++ X+ R* tv+ b++(+++) DI
D++(---) G(++) e*>++ h+ !r--- !y--
------END GEEK CODE BLOCK------

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Also fog can be turbulenced, which can sometimes be useful.

-- 
#macro M(A,N,D,L)plane{-z,-9pigment{mandel L*9translate N color_map{[0rgb x]
[1rgb 9]}scale<D,D*3D>*1e3}rotate y*A*8}#end M(-3<1.206434.28623>70,7)M(
-1<.7438.1795>1,20)M(1<.77595.13699>30,20)M(3<.75923.07145>80,99)// - Warp -

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In article <3C83DE53.D3143F74@scifi-fantasy.com>,
 "Timothy R. Cook" <tim### [at] scifi-fantasycom> wrote:

> Fog bounding objects.  I.e. fog only in this hollow cube.  Kinda like
> media, but quicker,

You can do this now with object attenuation. Make a transparent object 
and use fade_distance, fade_power, and fade_color.


> and without the scattering of light.

Fog doesn't scatter light anyway.

And solid media can render pretty fast...for this, you just need 
emitting and/or absorbing media, and you don't need lots of intervals or 
samples. In fact, 1 interval and 1 sample should work.

-- 
Christopher James Huff <chr### [at] maccom>
POV-Ray TAG e-mail: chr### [at] tagpovrayorg
TAG web site: http://tag.povray.org/

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"Christopher James Huff" wrote:
> You can do this now with object attenuation.
> Make a transparent object and use fade_distance,
> fade_power, and fade_color.

Fog and object attenuation have nothing to do with each other.

Fog fades to a specific color regardless of what objects are behind the fog.
Like a transmitting surface.

Attenuation filters light, so the color is multiplied by the color behind
the object. Like a filtering surface.

Rune

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