curves to a subdivision scheme for surface. Zorin, Schröder and Swelden (1996) noticed that the butterfly scheme cannot generate smooth surfaces for irregular triangle meshes and thus modified this scheme. Kobbelt (1996) further generalized the four-point interpolatory subdivision scheme for curves to the tensor product subdivision scheme for surfaces. In 1991, Nasri proposed a scheme for interpolating Doo-Sabin; while in 1993 Halstead, Kass, and DeRose proposed one for Catmull-Clark. Butterfly (1990), Triangles – named after the scheme's shape Modified Butterfly (1996), Quads – designed to overcome artifacts generated by irregular topology Kobbelt (1996), Quads – a variational subdivision method that tries to overcome uniform subdivision drawbacks Key developments 1978: Subdivision surfaces were described by Edwin Catmull and Jim Clark (see Catmull-Clark subdivision surface), and by Daniel Doo and Malcom Sabin (see Doo-Sabin subdivision surfaces). 1995: Ulrich Reif solved subdivision surface behaviour near extraordinary vertices. 1998: Jos Stam contributed a method for exact evaluation for Catmull-Clark subdivision surfaces under arbitrary parameter values. See also Geri's Game (1997) – a Pixar movie which pioneered use of subdivision surfaces to represent human skin Non-uniform rational B-spline (NURBS) surfaces – another method of representing curved surfaces References External links Geri's Game : Oscar winning animation by Pixar completed in 1997 that introduced subdivision surfaces using Catmull-Clark subdivision (along with cloth simulation) Subdivision for Modeling and Animation tutorial, SIGGRAPH 1999 course notes Subdivision for Modeling and Animation tutorial, SIGGRAPH 2000 course notes A unified approach to subdivision algorithms near extraordinary vertices, Ulrich Reif (Computer Aided Geometric Design 12(2):153–174 March 1995) Subdivision of Surface and Volumetric Meshes, software to perform subdivision using the most popular schemes Surface Subdivision Methods in CGAL, the Computational Geometry Algorithms Library 3D computer graphics Multivariate interpolation