\documentclass[varwidth=true, border=2pt]{standalone}
\usepackage{amsmath,amssymb}
\usepackage[utf8]{inputenc} % this is needed for umlauts
\usepackage[ngerman]{babel} % this is needed for umlauts
\usepackage[T1]{fontenc}    % this is needed for correct output of umlauts in pdf
\usepackage[bookmarks,bookmarksnumbered,hypertexnames=false,pdfpagelayout=OneColumn,colorlinks,hyperindex=false]{hyperref} % has to be after makeidx
\usepackage{pst-solides3d}
\usepackage{tikz}
\usepackage{tikz-3dplot}
\usepackage{tkz-fct}
\usetikzlibrary{3d,calc,intersections,er,arrows,positioning,shapes.misc,patterns}

\title{Torus}

\hypersetup{  
  pdftitle    = {Torus} 
}

\makeindex


\begin{document}
\input{torus}
\end{document}