-2 2 setxrange
-1.8 1.5 setyrange
100 setxunit

/alpha 6 def
/cerc {0 0 5} def

alpha cerc cpoint 4 SetCamPos
0 0 0 SetCamView

-10 10 setxrange3d
-3 3 setyrange3d

%5 -3 4 setlightsrc
1.5 setlightintensity

2 setlinejoin 
.7 setfillopacity

gris
2 setlinewidth
%/aretescachees false def
1 newtetraedre
dup 1 5 div solidtronque
dualpolyedreregulier
dup videsolid
dup (.8 setgray) inputcolors
dup [.5 .6] solidputhuecolors
dup drawsolid**