\documentclass[svgnames]{standalone} \usepackage{pgfplots} \pgfplotsset{compat=newest} \begin{document} \begin{tikzpicture} \begin{axis}[samples=30,ticks=none,xlabel={$V$},ylabel={$T$},zlabel={$F(T,V)$}] \addplot3[surf,color=DarkBlue,opacity=0.5,domain=-2:2,faceted color=black] {x^2-y^2}; \end{axis} \end{tikzpicture} \end{document}