BEZIER SURFACE

 Pierre Bezier (1910 - 1999): engineer at Régie Renault.

 Affine parametrization: . Polynomial surface of degree .

Given points  (called control points), the associated Bezier surface, or "tile", is the surface with the above parametrization; the portion of the surface for u and v 0 is included in the convex hull of the control points.

Example with n = 1 and m = 3 (8 control points)

If we write  the point with parameter t of the Bezier curve with control points , and  the point with parameter (u,v) of the Bezier surface with control points , then we have the relation: , which proves that the Bezier surface is the reunion of Bezier curves in two ways.

In particular, it contains the 4 Bezier curves with control points  and .

For n = m = 1 (4 control points), the Bezier surface is none other than the hyperbolic paraboloid the generatrices of which are the 4 lines  .

All polynomial algebraic surfaces are Bezier surfaces.

The Bezier surfaces are therefore special cases of spline surfaces.

There exists another kind of Bezier surface, defined by a triangulation instead of a "tiling".

© Robert FERRÉOL 2017