%autocrop
-13 10 setxrange
-10 10 setyrange
20 setxunit
6 20 15 SetCamPos
0 0 1 SetCamUp
0 0 0 SetCamView
2 setlinejoin 

/solidgrid false def
{orange} setlight
0 10 12 setlightsrc
2 setlightintensity

/gro {
4 dict begin
   /M defpoint3d
   /a .3 def
   /b 1 a 3 sqrt mul sub def
   /k M norme3d a mul b add def
   M k mulv3d
end
} def


2 [6] newcube
{0 0 -70 rotateOpoint3d} solidtransform
{gro} solidtransform
{10 dup dup scaleOpoint3d} solidtransform
drawsolid**