light_source {
  <0, 0, -5>
  color rgb 1
}
camera {
  location <0, 0, -5>
  look_at 0
}
box { -1, 1
  texture {
    material_map {
      gif "speck.gif"
      texture {
        gradient x
        texture_map {
          [.5 pigment { rgb x } ]
          [1 pigment { rgb y } ]
        }
      }
      texture { pigment { rgb z } }
    }
  }
}