// Last edited on 2014-05-07 20:10:51 by stolfilocal

#macro perna(rp)
  union{
    sphere{ <0,0,0>, 1.5*rp }
    cylinder{ <0,0,0>, <0,0,-3>, rp }
  }
#end

#macro segmento(ts)
  #local rb = 2;
  #local rp = 0.5;
  union{ 
    cylinder{ < -1, 0, 0 >, < +1, 0, 0 >, R }
    object{ perna(rp) translate -(rp+rb)*y }
    object{ perna(rp) scale < 1, -1, 1 > translate +(rp+rb)*y }
  }
#end

#declare pi = 3.1415962;

#macro pos(tt)
  < cos(2*pi * tt), sin(2*pi * tt), 0 >
#end

#macro vel(tt)
  < -2*pi*sin