# Draw many lines through the origin in 3D with TIKZ

Can you please help me find a systematic way of drawing many vectors through the origin in 3D so they resemble a sphere? I think dividing the sphere into 120 vectors in all directions should be enough.

## 1 Answer

\documentclass{article}
\usepackage{tikz}
\usepackage{tikz-3dplot}
\usetikzlibrary{calc,fadings,decorations.pathreplacing}

\begin{document}

\tdplotsetmaincoords{60}{120}
\begin{tikzpicture}
[scale=3, tdplot_main_coords, axis/.style={->}, vector/.style={-stealth}]

%standard tikz coordinate definition using x, y, z coords
\coordinate (O) at (0,0,0);

%tikz-3dplot coordinate definition using r, theta, phi coords
\foreach \a in {0, 20, 40, 60, 80, 100, 120, 140, 160, 180, 200, 220, 240, 260, 280, 300, 320, 340}
\foreach \b in {0, 20, 40, 60, 80, 100, 120, 140, 160}
%draw a vector from O to P
\draw[vector, color=black, opacity=0.4] (O) -- ({cos(\a)*sin(\b)}, {sin(\a)*sin(\b)}, {cos(\b)});

%draw axes
\draw[axis, thick] (-1,0,0) -- (2,0,0) node[anchor=north east]{$y,\beta$};
\draw[axis, thick] (0,-1,0) -- (0,2,0) node[anchor=north west]{$x, \alpha$};
\draw[axis, thick] (0,0,-1) -- (0,0,2) node[anchor=south]{$z, \gamma$};

\end{tikzpicture}

\end{document}


I used lots of other peoples' code and lost tracks of them. But this does the trick.