I am trying to get this plot that contains 2 skewed cones with the center projected onto the xy plane:
This is what I have so far as per the solution given here:
\documentclass[tikz, border=3pt]{standalone}
\usepackage{tikz,tikz-3dplot}
\tdplotsetmaincoords{80}{45}
\tdplotsetrotatedcoords{-90}{180}{-90}
%% style for surfaces
\tikzset{surface/.style={draw=blue!70!black, fill=blue!40!white, fill opacity=.6}}
%% macros to draw back and front of cones
%% optional first argument is styling; others are z, radius, side offset (in degrees)
\newcommand{\coneback}[4][]{
%% start at the correct point on the circle, draw the arc, then draw to the origin of the diagram, then close the path
\draw[canvas is xy plane at z=#2, #1] (45-#4:#3) arc (45-#4:225+#4:#3) -- (O) --cycle;
}
\newcommand{\conefront}[4][]{
\draw[canvas is xy plane at z=#2, #1] (45-#4:#3) arc (45-#4:-135+#4:#3) -- (O) --cycle;
}
\begin{document}
\begin{tikzpicture}[tdplot_main_coords]
\coordinate (O) at (0,0,0);
%% make sure to draw everything from back to front
%\coneback[surface]{-1.5}{2.5}{-15}
\coneback[surface]{-3}{2}{-10}
\draw (0,0,-5) -- (O);
\conefront[surface]{-3}{2}{-10}
\coneback[surface]{3}{-2}{-10}
\conefront[surface]{3}{-2}{-10}
\end{tikzpicture}
\end{document}
UPDATE
From the first solution given below, this is the output that I got when I used XeLaTeX to compile:
Am I missing some settings on my machine that is causing me to obtain this output? Thanks!



xelatexandshadows.blur. Let me also mention that I am not a fan of unaccepting answers to make the OP, who has spent time and efforts to help you, address additional requests. – Oct 17 '19 at 02:09