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

-1 1 setxrange
-1 1 setyrange
200 setxunit

30.01 30 50 SetCamPos
0 0 0 SetCamView
/ScreenDist .3 def

-10 10 setxrange3d
-3 3 setyrange3d
2 setlinejoin


/a 1 def
/b 1 def

/g {
3 dict begin
   settvar
#rpn# a*Cos(3*t)
#rpn# a*Sin(2*t)
#rpn# b*Sin(7*t)
end
} def

/g' {
3 dict begin
   settvar
#rpn# -3*a*Sin(3*t)
#rpn# 2*a*Cos(2*t)
#rpn# 7*b*Cos(7*t)
end
} def

/g'' {
3 dict begin
   settvar
#rpn# -9*a*Cos(3*t)
#rpn# -4*a*Sin(2*t)
#rpn# -49*b*Sin(7*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 [405 6] newtube
%dup (rouge) outputcolors
dup [.1 .3] solidputhuecolors
%dup videsolid

drawsolid**