2.1 Parametric 3D Curves: Theory
Curves and surfaces can have explicit, implicit, and parametric representations. Parametric representations are the most common in computer graphics.
Example:
In Fun3D:
x(u) = sin(u)*(exp(cos(u))-2*cos(4*u)-sin(u/12)^5)
y(u) = cos(u)*(exp(cos(u))-2*cos(4*u)-sin(u/12)^5)
z(u) = 0
See also:
9.3 Supported functions and syntax