选自

\documentclass[10pt,x11names, pdf]{standalone}\usepackage{pstricks-add}%\usepackage{pst-func, pst-plot}\begin{document}\psset{algebraic=true,dimen=middle,dotstyle=o,linewidth=0.8pt,arrowsize=3pt 2,arrowinset=0.25,unit=3,plotpoints = 2000}\begin{pspicture*}(-2,-2)(2,2) \psset{linecolor =SteelBlue4, linewidth = 1.2pt} \pscustom[fillstyle = solid, fillcolor =lightgray!25!LightSteelBlue2!10!]{ \parametricplot{-0.99}{0}{3*t/(1 + t^3) | 3*t^2/(1 + t^3)} \parametricplot{-600}{-1.01}{3*t/(1 + t^3) | 3*t^2/(1 + t^3)} }\pscustom[fillstyle = solid, fillcolor =LightSteelBlue2!25! ]{ \parametricplot{0}{5}{3*t/(1 + t^3) | 3*t^2/(1 + t^3)} \parametricplot{5}{200}{3*t/(1 + t^3) | 3*t^2/(1 + t^3)} \closepath } %\psline[linewidth = 0.4pt, linecolor = black](-2.5; 45)(2.5 ; 45) \psline[linewidth = 0.4pt, linecolor = black](-2,1)(2,-3)\psaxes[linecolor=gray,xAxis=true,yAxis=true,labels=none,ticks=none]{->}(0,0)(-2,-2)(2,2)\rput(-0.1,-0.1){$O$}\rput(1.95,-0.1){$x$}\rput(-0.1,1.95){$y$}\rput(-0.5,-0.08){$a$}\rput(-0.08,-0.5){$a$}\end{pspicture*}\end{document}

选自

\documentclass[border=5pt]{standalone}\usepackage{tikz}\usetikzlibrary{decorations,calc,intersections}%Mark Wibrow's code for stippling% https://tex.stackexchange.com/a/267037/3954\pgfkeys{/pgf/decoration/.cd,  stipple density/.store in=\pgfstippledensity,  stipple density=.1,  stipple scaling function/.store in=\pgfstipplescalingfunction,  stipple scaling function=sin(\pgfstipplex*180)*0.875+0.125,  stipple radius/.store in=\pgfstippleradius,  stipple radius=0.25pt}\pgfdeclaredecoration{stipple}{draw}{\state{draw}[width=\pgfdecorationsegmentlength]{  \pgfmathparse{\pgfdecoratedcompleteddistance/\pgfdecoratedpathlength}%  \let\pgfstipplex=\pgfmathresult%  \pgfmathparse{int(\pgfstippledensity*100)}%  \let\pgfstipplen=\pgfmathresult  \pgfmathloop  \ifnum\pgfmathcounter<\pgfmathresult\relax    \pgfpathcircle{%      \pgfpoint{(rnd)*\pgfdecorationsegmentlength}%        {(\pgfstipplescalingfunction)*(rnd^4)*\pgfdecorationsegmentamplitude+\pgfstippleradius}}%     {\pgfstippleradius}%  \repeatpgfmathloop}}\tikzset{stipple/.style={  decoration={stipple, segment length=2pt, #1},  decorate,  fill}}% end of stippling code\newcommand\DrawBlock[3]{\ifx#1b\relax  \path[draw]    (lm\the\numexpr#2-1\relax) -- ++(0,0,#3) coordinate (blocklf)    (bm\the\numexpr#2-1\relax) -- ++(0,0,#3) coordinate (blocklb)    (lm#2) -- ++(0,0,#3) coordinate (blockrf)    (bm#2) -- ++(0,0,#3) coordinate (blockrb);  \filldraw[fill=white,draw=black]    (lm\the\numexpr#2-1\relax) -- (blocklf) -- (blocklb) -- (blockrb) -- (blockrf) -- (lm#2);\else    \ifx#1f\relax    \path[draw]      (fm\the\numexpr#2-1\relax) -- ++(0,0,#3) coordinate (blocklf)      (lm\the\numexpr#2-1\relax) -- ++(0,0,#3) coordinate (blocklb)      (fm#2) -- ++(0,0,#3) coordinate (blockrf)      (lm#2) -- ++(0,0,#3) coordinate (blockrb);    \filldraw[fill=white,draw=black]      (fm\the\numexpr#2-1\relax) -- (blocklf) -- (blocklb) -- (blockrb) -- (blockrf) -- (fm#2);  \fi\fi\draw (blocklf) -- (blockrf);}\begin{document}\begin{tikzpicture}[y={(0:1cm)},x={(225:0.86cm)}, z={(90:1cm)}]% coordinates for the lower grid\path  (1,3,0) coordinate (bm0) --   (4,3,0) coordinate (fm0) coordinate[midway] (lm0) --  (4,8,0) coordinate[pos=0.25] (fm1) coordinate[midway] (fm2) coordinate[pos=0.75] (fm3) coordinate (fm4) --  (1,8,0) coordinate (bm4) coordinate[midway] (lm4)--  (bm0) coordinate[pos=0.25] (bm3) coordinate[midway] (bm2) coordinate[pos=0.75] (bm1);\draw[dashed]  (lm0) --   (lm4) coordinate[pos=0.25] (lm1) coordinate[midway] (lm2) coordinate[pos=0.75] (lm3);% the blocks\DrawBlock{b}{1}{4}\DrawBlock{b}{2}{3.7}\DrawBlock{b}{3}{4.3}\DrawBlock{b}{4}{5}\DrawBlock{f}{1}{3.3}\DrawBlock{f}{2}{3.5}\DrawBlock{f}{3}{4}\DrawBlock{f}{4}{4.7}\foreach \Point/\Height in {lm1/3.7,lm2/4.3,lm3/5}  \draw[ultra thin,dashed,opacity=0.2] (\Point) -- ++(0,0,\Height);% the lower grid\foreach \x in {1,2,3}  \draw[dashed] (fm\x) -- (bm\x);\draw[dashed] (fm0) -- (bm0) -- (bm4);\draw (fm0) -- (fm4) -- (bm4);\draw[dashed] (lm0) -- (lm4);% coordinates for the surface\coordinate (curvefm0) at ( $ (fm0) + (0,0,4) $ );\coordinate (curvebm0) at ( $ (bm0) + (0,0,4) $ );\coordinate (curvebm4) at ( $ (bm4) + (0,0,6) $ );\coordinate (curvefm4) at ( $ (fm4) + (0,0,5.7) $ );% the surface\filldraw[ultra thick,fill=gray!25,fill opacity=0.2]  (curvefm0) to[out=-30,in=210]   (curvefm4) to[out=-4,in=260]  (curvebm4) to[out=215,in=330]  (curvebm0) to[out=240,in=-20]  (curvefm0);% lines from grid to surface\draw[very thick,name path=leftline] (curvefm0) -- (fm0);\draw[very thick] (curvefm4) -- (fm4);\draw[very thick,name path=rightline] (curvebm4) -- (bm4);\draw[very thick,dashed] (curvebm0) -- (bm0);% coordinate system\coordinate (O) at (0,0,0);\draw[-latex] (O) -- +(5,0,0) node[above left] {$x$};\path[name path=yaxis] (O) -- +(0,10,0) coordinate (yaxisfinal) node[above] {$y$};\draw[-latex] (O) -- +(0,0,5) node[left] {$z$};\path[name intersections={of=yaxis and leftline,by={yaxis1}}];\path[name intersections={of=yaxis and rightline,by={yaxis2}}];\draw (O) -- (yaxis1);\draw[densely dashed,opacity=0.1] (yaxis1) -- (yaxis2);\draw[-latex] (yaxis2) -- (yaxisfinal);% the stippling\path[postaction={stipple={amplitude=1cm,stipple density=0.15}}]  ( $ (fm4) + (0,0,4.7) $ ) -- (fm4);\path[postaction={stipple={amplitude=1cm,stipple density=0.05}}]  ( $ (lm4) + (0,0,4.7) $ ) -- (lm4);% for debugging%\foreach \Name in {bm0,fm0,lm0,fm1,fm2,fm3,fm4,bm4,lm4,bm1,bm2,bm3,lm1,lm2,lm3,%%curvefm0,curvebm0,curvebm4,curvefm4}%  \node at (\Name) {\Name};  \end{tikzpicture}\end{document}