//  Wireframe box with unit half-side centered at origin
//  Last edited on 1999-02-06 04:49:19 by stolfi

//  Defines
//    unit_box

#declare unit_box =
  union{
    cylinder{ <-1,-1,-1>, <-1,-1,+1>, 0.02}
    cylinder{ <-1,+1,-1>, <-1,+1,+1>, 0.02}
    cylinder{ <+1,-1,-1>, <+1,-1,+1>, 0.02}
    cylinder{ <+1,+1,-1>, <+1,+1,+1>, 0.02}

    cylinder{ <-1,-1,-1>, <-1,+1,-1>, 0.02}
    cylinder{ <-1,-1,+1>, <-1,+1,+1>, 0.02}
    cylinder{ <+1,-1,-1>, <+1,+1,-1>, 0.02}
    cylinder{ <+1,-1,+1>, <+1,+1,+1>, 0.02}

    cylinder{ <-1,-1,-1>, <+1,-1,-1>, 0.02}
    cylinder{ <-1,-1,+1>, <+1,-1,+1>, 0.02}
    cylinder{ <-1,+1,-1>, <+1,+1,-1>, 0.02}
    cylinder{ <-1,+1,+1>, <+1,+1,+1>, 0.02}
    
    #if (unit_box_grid)
      cylinder{ <-1,-0.8,-1>, <-1,-0.8,+1>, 0.01}
      cylinder{ <-1,-0.6,-1>, <-1,-0.6,+1>, 0.01}
      cylinder{ <-1,-0.4,-1>, <-1,-0.4,+1>, 0.01}
      cylinder{ <-1,-0.2,-1>, <-1,-0.2,+1>, 0.01}
      cylinder{ <-1,00.0,-1>, <-1,00.0,+1>, 0.015}
      cylinder{ <-1,+0.2,-1>, <-1,+0.2,+1>, 0.01}
      cylinder{ <-1,+0.4,-1>, <-1,+0.4,+1>, 0.01}
      cylinder{ <-1,+0.6,-1>, <-1,+0.6,+1>, 0.01}
      cylinder{ <-1,+0.8,-1>, <-1,+0.8,+1>, 0.01}

      cylinder{ <-1,-1,-0.8>, <-1,+1,-0.8>, 0.01}
      cylinder{ <-1,-1,-0.6>, <-1,+1,-0.6>, 0.01}
      cylinder{ <-1,-1,-0.4>, <-1,+1,-0.4>, 0.01}
      cylinder{ <-1,-1,-0.2>, <-1,+1,-0.2>, 0.01}
      cylinder{ <-1,-1,00.0>, <-1,+1,00.0>, 0.015}
      cylinder{ <-1,-1,+0.2>, <-1,+1,+0.2>, 0.01}
      cylinder{ <-1,-1,+0.4>, <-1,+1,+0.4>, 0.01}
      cylinder{ <-1,-1,+0.6>, <-1,+1,+0.6>, 0.01}
      cylinder{ <-1,-1,+0.8>, <-1,+1,+0.8>, 0.01}
    #end

    texture{
      pigment{ color rgb <1.0,0.9,0.8> }
      finish { diffuse 0.1 ambient 0.9 }
    }
  }