// No fancy tricks, just minimal required code and whitespaces removed.

max_trace_level 20

sky_sphere
{ pigment
  { planar color_map
    { [0 rgb z][.9 rgb .9]
    }
  }
}

intersection
{ height_field
  { function 400, 400
    { pattern { granite }
    }
  }
  box { 0, .99 }
  hollow

  pigment { rgbt 1 }
  interior
  { media
    { scattering { 1, 1 }
    }
  }

  translate -<.45, .6, .3>
  scale <20, 5, 20>
}

light_source { x*9, 1.5 }