%% d'apres les donnees de
%% http://www.mathcurve.com/courbes3d/noeuds/noeuddetrefle.shtml

-1 1 setxrange
-1 1 setyrange
200 setxunit

0.01 0 20 SetCamPos
0 0 0 SetCamView
%/ScreenDist .05 def

-10 10 setxrange3d
-3 3 setyrange3d
2 setlinejoin


/g {
3 dict begin
   settvar
#rpn# Sin(2*t)
#rpn# Sin(t)*Cos(2*t)
#rpn# Cos(3*t)
end
} def

/g' {
3 dict begin
   settvar
#rpn# 2*Cos(2*t)
#rpn# Cos(t)*Cos(2*t) - 2*Sin(t)*Sin(2*t)
#rpn# -3*Sin(3*t)
end
} def

/g'' {
3 dict begin
   settvar
#rpn# -4*Sin(2*t)
#rpn# -Sin(t)*Cos(2*t) -2*Cos(t)*Sin(2*t) - 2*Cos(t)*Sin(2*t) - 4*Sin(t)*Cos(2*t)
#rpn# -3*Sin(3*t)
end
} def


%rouge
0 pi 2 mul {g} CourbeR3
%stop

.1 setlinewidth
/aretescachees false def

GetCamPos setlightsrc
%solidgridOff

0 2 pi mul (g) .1 [205 8] newtube
%dup (rouge) outputcolors
dup [.5 .6] solidputhuecolors
dup videsolid

drawsolid**