% 3D Cone
% Author: Gene Ressler. Adapted to TikZ by Kjell Magne Fauske.
% See http://www.frontiernet.net/~eugene.ressler/ for more details.
\documentclass{article}
\usepackage{tikz}



\begin{document}
\pagestyle{empty}

% The following code is generated by Sketch. I have edited it a bit
% to make it easier to read.
\begin{tikzpicture}[join=round]
    \tikzstyle{conefill} = [fill=blue!20,fill opacity=0.8]
    \tikzstyle{ann} = [fill=white,font=\footnotesize,inner sep=1pt]
    \tikzstyle{ghostfill} = [fill=white]
         \tikzstyle{ghostdraw} = [draw=black!50]
    \filldraw[conefill](-.775,1.922)--(-1.162,.283)--(-.274,.5)
                        --(-.183,2.067)--cycle;
    \filldraw[conefill](-.183,2.067)--(-.274,.5)--(.775,.424)
                        --(.516,2.016)--cycle;
    \filldraw[conefill](.516,2.016)--(.775,.424)--(1.369,.1)
                        --(.913,1.8)--cycle;
    \filldraw[conefill](-.913,1.667)--(-1.369,-.1)--(-1.162,.283)
                        --(-.775,1.922)--cycle;
    \draw(1.461,.107)--(1.734,.127);
    \draw[arrows=<->](1.643,1.853)--(1.643,.12);
    \filldraw[conefill](.913,1.8)--(1.369,.1)--(1.162,-.283)
                        --(.775,1.545)--cycle;
    \draw[arrows=->,line width=.4pt](.274,-.5)--(0,0)--(0,2.86);
    \draw[arrows=-,line width=.4pt](0,0)--(-1.369,-.1);
    \draw[arrows=->,line width=.4pt](-1.369,-.1)--(-2.1,-.153);
    \filldraw[conefill](-.516,1.45)--(-.775,-.424)--(-1.369,-.1)
                        --(-.913,1.667)--cycle;
    \draw(-1.369,.073)--(-1.369,2.76);
    \draw(1.004,1.807)--(1.734,1.86);
    \filldraw[conefill](.775,1.545)--(1.162,-.283)--(.274,-.5)
                        --(.183,1.4)--cycle;
    \draw[arrows=<->](0,2.34)--(-.913,2.273);
    \draw(-.913,1.84)--(-.913,2.447);
    \draw[arrows=<->](0,2.687)--(-1.369,2.587);
    \filldraw[conefill](.183,1.4)--(.274,-.5)--(-.775,-.424)
                        --(-.516,1.45)--cycle;
    \draw[arrows=<-,line width=.4pt](.42,-.767)--(.274,-.5);
    \node[ann] at (-.456,2.307) {$r_0$};
    \node[ann] at (-.685,2.637) {$r_1$};
    \node[ann] at (1.643,.987) {$h$};
    \path (.42,-.767) node[below] {$x$}
        (0,2.86) node[above] {$y$}
        (-2.1,-.153) node[left] {$z$};
    % Second version of the cone
    \begin{scope}[xshift=3.5cm]
    \filldraw[ghostdraw,ghostfill](-.775,1.922)--(-1.162,.283)--(-.274,.5)
                                   --(-.183,2.067)--cycle;
    \filldraw[ghostdraw,ghostfill](-.183,2.067)--(-.274,.5)--(.775,.424) 
                                   --(.516,2.016)--cycle;
    \filldraw[ghostdraw,ghostfill](.516,2.016)--(.775,.424)--(1.369,.1)
                                   --(.913,1.8)--cycle;
    \filldraw[ghostdraw,ghostfill](-.913,1.667)--(-1.369,-.1)--(-1.162,.283)
                                   --(-.775,1.922)--cycle;
    \filldraw[ghostdraw,ghostfill](.913,1.8)--(1.369,.1)--(1.162,-.283)
                                   --(.775,1.545)--cycle;
    \filldraw[ghostdraw,ghostfill](-.516,1.45)--(-.775,-.424)--(-1.369,-.1)
                                   --(-.913,1.667)--cycle;
    \filldraw[ghostdraw,ghostfill](.775,1.545)--(1.162,-.283)--(.274,-.5)
                                   --(.183,1.4)--cycle;
    \filldraw[fill=red,fill opacity=0.5](-.516,1.45)--(-.775,-.424)--(.274,-.5)
                                         --(.183,1.4)--cycle;
    \fill(-.775,-.424) circle (2pt);
    \fill(.274,-.5) circle (2pt);
    \fill(-.516,1.45) circle (2pt);
    \fill(.183,1.4) circle (2pt);
    \path[font=\footnotesize]
            (.913,1.8) node[right] {$i\hbox{$=$}0$}
            (1.369,.1) node[right] {$i\hbox{$=$}1$};
    \path[font=\footnotesize]
            (-.645,.513) node[left] {$j$}
            (.228,.45) node[right] {$j\hbox{$+$}1$};
    \draw (-.209,.482)+(-60:.25) [yscale=1.3,->] arc(-60:240:.25);
    \fill[black,font=\footnotesize]
                    (-.516,1.45) node [above] {$P_{00}$}
                    (-.775,-.424) node [below] {$P_{10}$}
                    (.183,1.4) node [above] {$P_{01}$}
                    (.274,-.5) node [below] {$P_{11}$};
    \end{scope}
\end{tikzpicture}

\end{document}

