\section{Truncate a solid's vertices}

The option \Lkeyword{trunc} allows us to \Index{truncate} a solid's vertices either
globally or individually. This option uses the key
\Lkeyword{trunccoeff} (value $0.25$ by default) which indicates the ratio
$k$ used for the \Index{truncation} ($0<k\leq 0.5$).
%
\begin{itemize}
  \item \texttt{\Lkeyword{trunc}=\Lkeyval{all}} truncates all the vertices;
  \item \texttt{\Lkeyword{trunc}=0 1 2 3} truncates the vertices 0, 1, 2 and 3.
\end{itemize}
%
\begin{LTXexample}[width=6cm]
\psset{viewpoint=50 50 30 rtp2xyz,Decran=25,lightsrc=viewpoint}
\begin{pspicture}(-3,-2)(2,2)
\psSolid[
   action=draw,
   object=cube,
   RotZ=30,
   trunccoeff=.2,
   trunc=all]%
\end{pspicture}
\end{LTXexample}

\begin{LTXexample}[width=6cm]
\psset{viewpoint=50 50 30 rtp2xyz,Decran=25,lightsrc=viewpoint}
\begin{pspicture}(-3,-2)(2,2)
\psSolid[action=draw,
   object=cube,
   RotZ=30,
   trunccoeff=.2,
   trunc=0 1 2 3]%
\end{pspicture}
\end{LTXexample}

\endinput 