Rolling curve / 05
Dual-fold hypotrochoid
Geometry
A circle of radius r rolls inside a fixed circle of radius R, and the rolling term is multiplied by sin(2·t).
x(t) = (R − r)·cos t · sin(2·t) + d·cos((R − r)/r · t)y(t) = (R − r)·sin t · sin(2·t) − d·sin((R − r)/r · t)