\begin{pspicture}(-4,-4)(4,4)
\psset{lightsrc=50 30 20,viewpoint=20 10 5,Decran=50}
\psSolid[object=octahedron,
   a=2,
   trunc=all,
   hue=.5 .6,
   trunccoeff=.3333,
   numfaces=all,
   action=draw*]
\end{pspicture}
\end{center}