A nonuniform rational B-spline surface of degree (p, q) is defined by S(u, v) = ( sum_(i = 0)^m sum_(j = 0)^n N_(i, p)(u) N_(j, q)(v) w_(i, j) P_(i, j))/( sum_(i = 0)^m sum_(j = 0)^n N_(i, p)(u) N_(j, q)(v) w_(i, j)), where N_(i, p) and N_(j, q) are the B-spline basis functions, P_(i, j) are control points, and the weight w_(i, j) of P_(i, j) is the last ordinate of the homogeneous point (P_(i, j))^w. NURBS surfaces are implemented in the Wolfram Language as BSplineSurface[array].

Bézier curve | B-spline | NURBS curve