Spline curve - Modeling and Rendering
Spline curve is created by using Control points that control the shape of the curve Spline curve is a composite curve formed along with sections that are polynomial in nature. Such pieces are joined together in a way that continuity condition at boundary is kept. A piecewise parametric polynomial section while passes through each control point curve is termed to Interpolate the set of control points refer the figure 15. Conversely, when polynomial is not suited for the set to very control point, which is termed to approximate set of control point.
Figure (a): Interpolating curve Figure (b): Approximating Curve