Opacity di PsTricks: non va !!
La seguente immagine, suddivisa in tre parti, mostra eloquentemente il problema: i poligoni interni, con relative sfumature, non si vedono.
http://img377.imageshack.us/img377/2968/sc095.jpg
Il sorgente Latex/Pstricks (ricavato da GeoGebra) è riportato sotto. Aggiungo solo che la compilazione (+visualizzazione) in PostScript è avvenuta con questi comandi batch del DOS:
`@echo off
latex %1
dvips -Ppdf %1.dvi
c:\programmi\ghostgum\gsview\gsview32 %1.ps
`
mentre il file poli2.pdf è stato ricavato per conversione di poli2.ps di gsview 4.9
Grazie per le risposte.
Aggiornamento
Anche esportando la figura in formato PGF/Tikz si verifica lo stesso inconveniente. Il relativo codice (od2.tex) è accodato a quello appresso. Da notare pure che il formato PGF/Tikz non contiene opacity
—————-
`% —- file poli2.tex —–
\documentclass[10pt]{article}
\usepackage{pstricks-add}
\pagestyle{empty}
\begin{document}
\newrgbcolor{xdxdff}{0.49 0.49 1}
\newrgbcolor{zzttqq}{0.6 0.2 0}
\psset{xunit=1.0cm,yunit=1.0cm}
\begin{pspicture*}(-5.82,-1)(5,8.5)
\psgrid[subgriddiv=0,gridlabels=0,gridcolor=lightgray](0,0)(-5.82,-1)(5,8.5)
\psset{xunit=1.0cm,yunit=1.0cm,algebraic=true,dotstyle=o,dotsize=3pt 0,linewidth=0.8pt,arrowsize=3pt 2,arrowinset=0.25}
\psaxes[labelFontSize=\scriptstyle,xAxis=true,yAxis=true,Dx=1,Dy=1,ticksize=-2pt 0,subticks=2]{->}(0,0)(-5.82,-1)(5,8.5)
\pspolygon[linestyle=none,fillstyle=solid,fillcolor=zzttqq,opacity=0.1](-1,0)(1,0)(0,1.73)
\pspolygon[linestyle=none,fillstyle=solid,fillcolor=zzttqq,opacity=0.1](-1,0)(1,0)(1.62,1.9)(0,3.08)(-1.62,1.9)
\pspolygon[linestyle=none,fillstyle=solid,fillcolor=zzttqq,opacity=0.1](-1,0)(1,0)(2.25,1.56)(1.8,3.51)(0,4.38)(-1.8,3.51)(-2.25,1.56)
\pspolygon[linestyle=none,fillstyle=solid,fillcolor=zzttqq,opacity=0.1](-1,0)(1,0)(2.53,1.29)(2.88,3.26)(1.88,4.99)(0,5.67)(-1.88,4.99)(-2.88,3.26)(-2.53,1.29)
\pspolygon[linestyle=none,fillstyle=solid,fillcolor=zzttqq,opacity=0.1](-1,0)(1,0)(2.68,1.08)(3.51,2.9)(3.23,4.88)(1.92,6.39)(0,6.96)(-1.92,6.39)(-3.23,4.88)(-3.51,2.9)(-2.68,1.08)
\psline[linecolor=zzttqq](-1,0)(1,0)
\psline[linecolor=zzttqq](1,0)(0,1.73)
\psline[linecolor=zzttqq](0,1.73)(-1,0)
\psline[linecolor=zzttqq](-1,0)(1,0)
\psline[linecolor=zzttqq](1,0)(1.62,1.9)
\psline[linecolor=zzttqq](1.62,1.9)(0,3.08)
\psline[linecolor=zzttqq](0,3.08)(-1.62,1.9)
\psline[linecolor=zzttqq](-1.62,1.9)(-1,0)
\psline[linecolor=zzttqq](-1,0)(1,0)
\psline[linecolor=zzttqq](1,0)(2.25,1.56)
\psline[linecolor=zzttqq](2.25,1.56)(1.8,3.51)
\psline[linecolor=zzttqq](1.8,3.51)(0,4.38)
\psline[linecolor=zzttqq](0,4.38)(-1.8,3.51)
\psline[linecolor=zzttqq](-1.8,3.51)(-2.25,1.56)
\psline[linecolor=zzttqq](-2.25,1.56)(-1,0)
\psline[linecolor=zzttqq](-1,0)(1,0)
\psline[linecolor=zzttqq](1,0)(2.53,1.29)
\psline[linecolor=zzttqq](2.53,1.29)(2.88,3.26)
\psline[linecolor=zzttqq](2.88,3.26)(1.88,4.99)
\psline[linecolor=zzttqq](1.88,4.99)(0,5.67)
\psline[linecolor=zzttqq](0,5.67)(-1.88,4.99)
\psline[linecolor=zzttqq](-1.88,4.99)(-2.88,3.26)
\psline[linecolor=zzttqq](-2.88,3.26)(-2.53,1.29)
\psline[linecolor=zzttqq](-2.53,1.29)(-1,0)
\psline[linecolor=zzttqq](-1,0)(1,0)
\psline[linecolor=zzttqq](1,0)(2.68,1.08)
\psline[linecolor=zzttqq](2.68,1.08)(3.51,2.9)
\psline[linecolor=zzttqq](3.51,2.9)(3.23,4.88)
\psline[linecolor=zzttqq](3.23,4.88)(1.92,6.39)
\psline[linecolor=zzttqq](1.92,6.39)(0,6.96)
\psline[linecolor=zzttqq](0,6.96)(-1.92,6.39)
\psline[linecolor=zzttqq](-1.92,6.39)(-3.23,4.88)
\psline[linecolor=zzttqq](-3.23,4.88)(-3.51,2.9)
\psline[linecolor=zzttqq](-3.51,2.9)(-2.68,1.08)
\psline[linecolor=zzttqq](-2.68,1.08)(-1,0)
\psdots[dotstyle=*,linecolor=xdxdff](-1,0)
\psdots[dotstyle=*,linecolor=xdxdff](1,0)
\psdots[dotstyle=*,linecolor=darkgray](0,1.73)
\psdots[dotstyle=*,linecolor=darkgray](1.62,1.9)
\psdots[dotstyle=*,linecolor=darkgray](0,3.08)
\psdots[dotstyle=*,linecolor=darkgray](-1.62,1.9)
\psdots[dotstyle=*,linecolor=darkgray](2.25,1.56)
\psdots[dotstyle=*,linecolor=darkgray](1.8,3.51)
\psdots[dotstyle=*,linecolor=darkgray](0,4.38)
\psdots[dotstyle=*,linecolor=darkgray](-1.8,3.51)
\psdots[dotstyle=*,linecolor=darkgray](-2.25,1.56)
\psdots[dotstyle=*,linecolor=darkgray](2.53,1.29)
\psdots[dotstyle=*,linecolor=darkgray](2.88,3.26)
\psdots[dotstyle=*,linecolor=darkgray](1.88,4.99)
\psdots[dotstyle=*,linecolor=darkgray](0,5.67)
\psdots[dotstyle=*,linecolor=darkgray](-1.88,4.99)
\psdots[dotstyle=*,linecolor=darkgray](-2.88,3.26)
\psdots[dotstyle=*,linecolor=darkgray](-2.53,1.29)
\psdots[dotstyle=*,linecolor=darkgray](2.68,1.08)
\psdots[dotstyle=*,linecolor=darkgray](3.51,2.9)
\psdots[dotstyle=*,linecolor=darkgray](3.23,4.88)
\psdots[dotstyle=*,linecolor=darkgray](1.92,6.39)
\psdots[dotstyle=*,linecolor=darkgray](0,6.96)
\psdots[dotstyle=*,linecolor=darkgray](-1.92,6.39)
\psdots[dotstyle=*,linecolor=darkgray](-3.23,4.88)
\psdots[dotstyle=*,linecolor=darkgray](-3.51,2.9)
\psdots[dotstyle=*,linecolor=darkgray](-2.68,1.08)
\end{pspicture*}
\end{document}
`
`% ——- od2.tex —————–
\documentclass[10pt]{article}
\usepackage{pgf,tikz}
\usetikzlibrary{arrows}
\pagestyle{empty}
\begin{document}
\definecolor{uququq}{rgb}{0.25,0.25,0.25}
\definecolor{zzttqq}{rgb}{0.6,0.2,0}
\definecolor{xdxdff}{rgb}{0.49,0.49,1}
\definecolor{cqcqcq}{rgb}{0.75,0.75,0.75}
\begin{tikzpicture}[line cap=round,line join=round,>=triangle 45,x=1.0cm,y=1.0cm]
\draw (-5.82,-1.64) grid (6.9,8.54);
\draw[->,color=black] (-5.82,0) — (6.9,0);
\foreach \x in {-5,-4,-3,-2,-1,1,2,3,4,5,6}
\draw[shift={(\x,0)},color=black] (0pt,2pt) — (0pt,-2pt) node[below] {\footnotesize $\x$};
\draw[->,color=black] (0,-1.64) — (0,8.54);
\foreach \y in {-1,1,2,3,4,5,6,7,8}
\draw[shift={(0,\y)},color=black] (2pt,0pt) — (-2pt,0pt) node
{\footnotesize $\y$};
\draw (0pt,-10pt) node
{\footnotesize $0$};
\clip(-5.82,-1.64) rectangle (6.9,8.54);
\fill (-1,0) — (1,0) — (0,1.73) — cycle;
\fill (-1,0) — (1,0) — (1.62,1.9) — (0,3.08) — (-1.62,1.9) — cycle;
\fill (-1,0) — (1,0) — (2.25,1.56) — (1.8,3.51) — (0,4.38) — (-1.8,3.51) — (-2.25,1.56) — cycle;
\fill (-1,0) — (1,0) — (2.53,1.29) — (2.88,3.26) — (1.88,4.99) — (0,5.67) — (-1.88,4.99) — (-2.88,3.26) — (-2.53,1.29) — cycle;
\fill (-1,0) — (1,0) — (2.68,1.08) — (3.51,2.9) — (3.23,4.88) — (1.92,6.39) — (0,6.96) — (-1.92,6.39) — (-3.23,4.88) — (-3.51,2.9) — (-2.68,1.08) — cycle;
\draw (-1,0)– (1,0);
\draw (1,0)– (0,1.73);
\draw (0,1.73)– (-1,0);
\draw (-1,0)– (1,0);
\draw (1,0)– (1.62,1.9);
\draw (1.62,1.9)– (0,3.08);
\draw (0,3.08)– (-1.62,1.9);
\draw (-1.62,1.9)– (-1,0);
\draw (-1,0)– (1,0);
\draw (1,0)– (2.25,1.56);
\draw (2.25,1.56)– (1.8,3.51);
\draw (1.8,3.51)– (0,4.38);
\draw (0,4.38)– (-1.8,3.51);
\draw (-1.8,3.51)– (-2.25,1.56);
\draw (-2.25,1.56)– (-1,0);
\draw (-1,0)– (1,0);
\draw (1,0)– (2.53,1.29);
\draw (2.53,1.29)– (2.88,3.26);
\draw (2.88,3.26)– (1.88,4.99);
\draw (1.88,4.99)– (0,5.67);
\draw (0,5.67)– (-1.88,4.99);
\draw (-1.88,4.99)– (-2.88,3.26);
\draw (-2.88,3.26)– (-2.53,1.29);
\draw (-2.53,1.29)– (-1,0);
\draw (-1,0)– (1,0);
\draw (1,0)– (2.68,1.08);
\draw (2.68,1.08)– (3.51,2.9);
\draw (3.51,2.9)– (3.23,4.88);
\draw (3.23,4.88)– (1.92,6.39);
\draw (1.92,6.39)– (0,6.96);
\draw (0,6.96)– (-1.92,6.39);
\draw (-1.92,6.39)– (-3.23,4.88);
\draw (-3.23,4.88)– (-3.51,2.9);
\draw (-3.51,2.9)– (-2.68,1.08);
\draw (-2.68,1.08)– (-1,0);
\fill (-1,0) circle (1.5pt);
\fill (1,0) circle (1.5pt);
\fill (0,1.73) circle (1.5pt);
\fill (1.62,1.9) circle (1.5pt);
\fill (0,3.08) circle (1.5pt);
\fill (-1.62,1.9) circle (1.5pt);
\fill (2.25,1.56) circle (1.5pt);
\fill (1.8,3.51) circle (1.5pt);
\fill (0,4.38) circle (1.5pt);
\fill (-1.8,3.51) circle (1.5pt);
\fill (-2.25,1.56) circle (1.5pt);
\fill (2.53,1.29) circle (1.5pt);
\fill (2.88,3.26) circle (1.5pt);
\fill (1.88,4.99) circle (1.5pt);
\fill (0,5.67) circle (1.5pt);
\fill (-1.88,4.99) circle (1.5pt);
\fill (-2.88,3.26) circle (1.5pt);
\fill (-2.53,1.29) circle (1.5pt);
\fill (2.68,1.08) circle (1.5pt);
\fill (3.51,2.9) circle (1.5pt);
\fill (3.23,4.88) circle (1.5pt);
\fill (1.92,6.39) circle (1.5pt);
\fill (0,6.96) circle (1.5pt);
\fill (-1.92,6.39) circle (1.5pt);
\fill (-3.23,4.88) circle (1.5pt);
\fill (-3.51,2.9) circle (1.5pt);
\fill (-2.68,1.08) circle (1.5pt);
\end{tikzpicture}
\end{document}
`