\documentclass[border=10pt]{standalone}
\usepackage{asymptote}
\begin{document}
\begin{asy}[width=\the\linewidth,inline=true]
settings.outformat="pdf";
settings.render=0;
settings.prc=false;
import graph3;
import tube;
size(200,0);
currentlight.background=paleyellow+opacity(0.0);
currentprojection=orthographic(camera=(-10,49,-58),up=(0.92,0.36,0.14));
real x(real t){return sin(2pi*t)+2sin(2*2pi*t);}
real y(real t){return cos(2pi*t)-2cos(2*2pi*t);}
real z(real t){return -sin(3*2pi*t);}
guide3 g=graph(x,y,z, 0, 1,operator..);
pair[][] p={
{(-40, 20),( -56.8421, 23.4210),( -78.9473, 28.6842),(-90, 20)},
{(-90, 20),(-101.0526, 11.3157),(-101.0526,-11.3157),(-90,-20)},
{(-90,-20),( -78.9473,-28.6842),( -56.8421,-23.4210),(-40,-20)},
{(-40,-20),( -23.1578,-16.5789),( -11.5789,-15 ),( 0,-15)},
{( 0,-15),( 11.5789,-15 ),( 23.1578,-16.5789),( 40,-20)},
{( 40,-20),( 56.8421,-23.4210),( 78.9473,-28.6842),( 90,-20)},
{( 90,-20),( 101.0526,-11.3157),( 101.0526, 11.3157),( 90, 20)},
{( 90, 20),( 78.9473, 28.6842),( 56.8421, 23.4210),( 40, 20)},
{( 40, 20),( 23.1578, 16.5789),( 11.5789, 15 ),( 0, 15)},
{( 0, 15),( -11.5789, 15 ),( -23.1578, 16.5789),(-40, 20)}
};
pen paint(real t){return hsv(t*360*0.1,0.997,0.997);}
guide gx=p[0][0];
for(int i=0;i
Source: TeX.SE