Q uadric surfaces such as cylinders and spheres play a fundamental role in CAGD.
This paper describes a new method for creating triangular surface patches on a quadric
surface. The surface patches are defined using a restricted type of quadratic Bezier
control polyhedron. The control polyhedron and the resulting quadric surface patch
satisfy all of the standard properties of parametric Bezier surfaces, including interpolation
of the corners of the control polyhedron and the convex hull property. A new
technique for creating a C1 mesh of these quadric surface patches is also introduced.