"Warp" <war### [at] tagpovrayorg> wrote in message
news:3e5b632b@news.povray.org...
>
>   Ok, the example is good in the sense that it demonstrates how you can
> use multiple pigments in a sky sphere. However, the generated clouds don't
> look good at all, and I have seen several times how it teaches a bad habit
> to people (ie. to put clouds in the sky sphere).
>
>   The easiest way of getting realistic-looking clouds is, of course, using
> a plane.

Hmm, yeah... although, bad habit or not it's all about using the sky_sphere
not planes. Clouds happen to be easy if you do it that way. I made an
attempt to change it anyhow, just to see how it might look if done a little
differently. What occured to me while doing so I began to wonder why the
light source wasn't moved into position where the faked Sun is at. If
anything, I think I'd change that. But I was also able to get a fairly
decent cloudy sky by simply rotating the gradient color map separate from
the clouds and scaling the clouds much smaller in the y direction.
Here's the whole scene file, below, and you can probably guess that in
making such changes the whole section of the tutorial would need to be
redone. It's overkill. However, if the clouds were transformed differently,
i.e. scale <0.2,0.05,0.2> and not rotated with the background colors, it
should be suitable without making further changes IMHO.

  #include "colors.inc"
  camera {
    location <0, 1, -4>
    look_at <0, 2, 0>
    angle 80
  }
  light_source { 1000*z, color White parallel point_at 0 rotate -15*x }
  sphere {
    2*y, 1
    pigment { color rgb <1, 1, 1> }
    finish { ambient 0.2 diffuse 0 reflection 0.6 }
  }
  sky_sphere {
    pigment {
      gradient y
      color_map {
        [0.000 0.002 color rgb <1.0, 0.4, 0.3>
                     color rgb <1.0, 0.3, 0.2>] // sun's outer edge
        [0.002 0.100 color rgb <0.8, 0.2, 0.1>
                     color rgb <0.7, 0.3, 0.4>]
        [0.100 1.000 color rgb <0.7, 0.3, 0.4>
                     color rgb <0.2, 0.4, 0.8>]
      }
      scale 2
      translate -y
    rotate -135*x
    }
    pigment {
      bozo
      turbulence 0.65
      octaves 6
      omega 0.7
      lambda 2
      color_map {
          [0.0 0.1 color rgb <0.85, 0.85, 0.85>
                   color rgb <0.75, 0.75, 0.75>]
          [0.1 0.5 color rgb <0.75, 0.75, 0.75>
                   color rgbt <1, 1, 1, 1>]
          [0.5 1.0 color rgbt <1, 1, 1, 1>
                   color rgbt <1, 1, 1, 1>]
      }
      scale <0.2, 0.05, 0.2>
      rotate -15*x
    }
  }
  plane {
    y, 0
    pigment { color Green }
    finish { ambient 0.3 diffuse 0.7 }
  }
  fog {
   fog_type 2
   fog_alt 1
   fog_offset 0
   distance 20
   color <0.6,0.5,0.5>
  }

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