3.1 Parametric 3D Surfaces: 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,v) = (3*(1+sin(v)) + 2*(1-cos(v)/2)*cos(u))*cos(v)
Y(u,v) = -2*(1-cos(v)/2) * sin(u)
Z(u,v) = (4+2*(1-cos(v)/2)*cos(u))*sin(v)
See also:
9.3 Supported functions and syntax