%% d'apres les donnees de %% http://www.mathcurve.com/courbes3d/noeuds/noeuddetrefle.shtml -1 1 setxrange -1 1 setyrange 200 setxunit 30.01 30 20 SetCamPos 0 0 0 SetCamView %/ScreenDist .05 def -10 10 setxrange3d -3 3 setyrange3d 2 setlinejoin /g { 3 dict begin settvar #rpn# Cos(t) + 2*Cos(2*t) #rpn# Sin(t) - 2*Sin(2*t) #rpn# 2*Sin(3*t) end } def /g' { 3 dict begin settvar #rpn# -Sin(t) - 4*Sin(2*t) #rpn# Cos(t) - 4*Cos(2*t) #rpn# 6*Cos(3*t) end } def /g'' { 3 dict begin settvar #rpn# -Cos(t) - 8*Cos(2*t) #rpn# -Sin(t) + 8*Sin(2*t) #rpn# -18*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) .25 [202 8] newtube %dup (rouge) outputcolors dup [.5 .6] solidputhuecolors %dup videsolid drawsolid**