Mathematical Methods in Computer Graphics ByungGook Lee Dongseo

Mathematical Methods in Computer Graphics Byung-Gook Lee Dongseo Univ. http: //kowon. dongseo. ac. kr/~lbg/ Mathematical Methods in Computer Graphics, Duksung Univ. Nov. 1. 2006, lbg@dongseo. ac. kr

Mathematical Methods in Computer Graphics, Duksung Univ. Nov. 1. 2006, lbg@dongseo. ac. kr

Computer Graphics The generation of graphical output using a computer • by developing software to accomplish the task • by using pre-existing application software like Photoshop, 3 D Studio Max, Maya, … Mathematical Methods in Computer Graphics, Duksung Univ. Nov. 1. 2006, lbg@dongseo. ac. kr

Computer Graphics • Modeling • Animation • Rendering Mathematical Methods in Computer Graphics, Duksung Univ. Nov. 1. 2006, lbg@dongseo. ac. kr

Modeling • The creation of mathematical models of 2 D and 3 D objects in the 3 D environment of a computer. Mathematical Methods in Computer Graphics, Duksung Univ. Nov. 1. 2006, lbg@dongseo. ac. kr

Animation • Topics include traditional principles of animation, kinematic and dynamic modeling techniques, physical simulation, procedural methods, and motion capture based animation. Mathematical Methods in Computer Graphics, Duksung Univ. Nov. 1. 2006, lbg@dongseo. ac. kr

Rendering • These models, starting as a wire frame model, are digitally wrapped with textures and rendered with reflections, transparencies, and shadows to give a photo-realistic view of the object or building. Mathematical Methods in Computer Graphics, Duksung Univ. Nov. 1. 2006, lbg@dongseo. ac. kr

http: //www. cult 3 d. com/ Web 3 D Mathematical Methods in Computer Graphics, Duksung Univ. Nov. 1. 2006, lbg@dongseo. ac. kr

CAGD Computer Aided Geometric Design § § § § interpolation spline bezier B-spline NURBS subdivision simplification parametrization CAGD is a branch of applied mathematics concerned with algorithms for the design of smooth curves and surfaces and for their efficients mathematical representation. Mathematical Methods in Computer Graphics, Duksung Univ. Nov. 1. 2006, lbg@dongseo. ac. kr

Affine combination • Linear combinations • Affine(Barycentric) combinations • Convex combinations • Barycentric coordinates Mathematical Methods in Computer Graphics, Duksung Univ. Nov. 1. 2006, lbg@dongseo. ac. kr

Affine combination Euclidean coordinate system Coordinate-free system Mathematical Methods in Computer Graphics, Duksung Univ. Nov. 1. 2006, lbg@dongseo. ac. kr

Polynomial interpolation Mathematical Methods in Computer Graphics, Duksung Univ. Nov. 1. 2006, lbg@dongseo. ac. kr

General polynomial Interpolation • Lagrange polynomials Mathematical Methods in Computer Graphics, Duksung Univ. Nov. 1. 2006, lbg@dongseo. ac. kr

Examples of cubic interpolation Mathematical Methods in Computer Graphics, Duksung Univ. Nov. 1. 2006, lbg@dongseo. ac. kr

Bezier • Paul de Faget de Casteljau, Citroen, 1959 • Pierre Bezier, Renault, UNISUF system, 1962 • A. R. Forrest, Cambridge, 1970 Mathematical Methods in Computer Graphics, Duksung Univ. Nov. 1. 2006, lbg@dongseo. ac. kr

Bezier Mathematical Methods in Computer Graphics, Duksung Univ. Nov. 1. 2006, lbg@dongseo. ac. kr

Representation Bezier Mathematical Methods in Computer Graphics, Duksung Univ. Nov. 1. 2006, lbg@dongseo. ac. kr

Properties of Bezier • • • Affine invariance Convex hull property Endpoint interpolation Symmetry Linear precision Pseudo-local control S Mathematical Methods in Computer Graphics, Duksung Univ. Nov. 1. 2006, lbg@dongseo. ac. kr

Pierre BEZIER died on November 25, 1999. The following short biography has been published in volume 22, number 9 (november 1990) of "Computer Aided Design", a special issue devoted to Bezier techniques. Pierre Etienne Bezier was born on September 1, 1910 in Paris. Son and grandson of engineers, he chose this profession too and enrolled to study mechanical engineering at the Ecole des Arts et Metiers and received his degree in 1930. In the same year he entered the Ecole Superieure d'Electricite and earnt a second degree in electrical engineering in 1931. In 1977, 46 years later, he received his DSc degree in mathematics from the University of Paris. In 1933, aged 23, Bezier entered Renault and worked for this company for 42 years. He started as Tool Setter, became Tool Designer in 1934 and Head of the Tool Design Office in 1945. In 1948, as Director of Production Engineering he was responsable for the design of the transfer lines producing most of the 4 CV mechanical parts. In 1957, he became Director of Machine Tool Division and was responsable for the automatic assembly of mechanical components, and for the design and production of an NC drilling and milling machine, most probably one of the first machines in Europe. Bezier become managing staff member for technical development in 1960 and held this position until 1975 when he retired. Bezier started his research in CADCAM in 1960 when he devoted a substantial amount of his time working on his UNISURF system. From 1960, his research interest focused on drawing machines, computer control, interactive freeform curve and surface design and 3 D milling for manufactoring clay models and masters. His system was launched in 1968 and has been in full use since 1975 supporting about 1500 staff members today. Bezier's academic career began in 1968 when he became Professor of Production Engineering at the Conservatoire National des Arts et Metiers. He held this position until 1979. He wrote four books, numerous papers and received several distinctions including the "Steven Anson Coons" of the Association for Computing Machinery and the "Doctor Honoris Causa" of the Technical University Berlin. He is an honorary member of the American Society of Mechanical Engineers and of the Societe Belge des Mecaniciens, ex-president of the Societe des Ingenieurs et Scientifiques de France, Societe des Ingenieurs Arts et Metiers, and he was one of the first Advisory Editors of "Computer-Aided Design". Christophe Rabut, Departement de Genie Mathematique Institut National des Sciences Appliquees 135, avenue de Rangueil F-31077 TOULOUSE Cedex 4 (France) Mathematical Methods in Computer Graphics, Duksung Univ. Nov. 1. 2006, lbg@dongseo. ac. kr

Bezier Degree Reduction Mathematical Methods in Computer Graphics, Duksung Univ. Nov. 1. 2006, lbg@dongseo. ac. kr

Spline curve • J. Ferguson , Boeing Co. , 1963 • C. de Boor, W. Gordon, General Motors, 1963 • to interpolate given data • piecewise polynomial curves with certain differentiability constraints • not to design free form curves Mathematical Methods in Computer Graphics, Duksung Univ. Nov. 1. 2006, lbg@dongseo. ac. kr

Piecewise cubic hermite interpolation Mathematical Methods in Computer Graphics, Duksung Univ. Nov. 1. 2006, lbg@dongseo. ac. kr

Cubic spline interpolation Mathematical Methods in Computer Graphics, Duksung Univ. Nov. 1. 2006, lbg@dongseo. ac. kr

B-spline • C. de Boor, 1972 • W. Gordon, Richard F. Riesenfeld, 1974 • • Larry L. Schumaker Tom Lyche Nira Dyn Cohen Mathematical Methods in Computer Graphics, Duksung Univ. Nov. 1. 2006, lbg@dongseo. ac. kr

B-spline Mathematical Methods in Computer Graphics, Duksung Univ. Nov. 1. 2006, lbg@dongseo. ac. kr

Linear splines Mathematical Methods in Computer Graphics, Duksung Univ. Nov. 1. 2006, lbg@dongseo. ac. kr

Quadratic splines Mathematical Methods in Computer Graphics, Duksung Univ. Nov. 1. 2006, lbg@dongseo. ac. kr

Quadratic splines Mathematical Methods in Computer Graphics, Duksung Univ. Nov. 1. 2006, lbg@dongseo. ac. kr

Representation splines Mathematical Methods in Computer Graphics, Duksung Univ. Nov. 1. 2006, lbg@dongseo. ac. kr

Cubic splines Mathematical Methods in Computer Graphics, Duksung Univ. Nov. 1. 2006, lbg@dongseo. ac. kr

Spline problems • • Degree Elevation Degree Reduction Knot Insertion Knot Deletion Mathematical Methods in Computer Graphics, Duksung Univ. Nov. 1. 2006, lbg@dongseo. ac. kr

Subdivision schemes Mathematical Methods in Computer Graphics, Duksung Univ. Nov. 1. 2006, lbg@dongseo. ac. kr

Subdivision Surfaces Mathematical Methods in Computer Graphics, Duksung Univ. Nov. 1. 2006, lbg@dongseo. ac. kr

http: //www. cgal. org/Tutorials/Polyhedron/ Subdivision Surfaces Tony Derose Pixar Animation Studios Geri’s game Mathematical Methods in Computer Graphics, Duksung Univ. Nov. 1. 2006, lbg@dongseo. ac. kr

Quasi-interpolants Mathematical Methods in Computer Graphics, Duksung Univ. Nov. 1. 2006, lbg@dongseo. ac. kr

Polygonal Simplification Mathematical Methods in Computer Graphics, Duksung Univ. Nov. 1. 2006, lbg@dongseo. ac. kr

Multiresolution Mathematical Methods in Computer Graphics, Duksung Univ. Nov. 1. 2006, lbg@dongseo. ac. kr

Parametrization 3 D mesh parameterization with fixed boundary Mathematical Methods in Computer Graphics, Duksung Univ. Nov. 1. 2006, lbg@dongseo. ac. kr

Texture Mapping Mathematical Methods in Computer Graphics, Duksung Univ. Nov. 1. 2006, lbg@dongseo. ac. kr

Image Compression Mathematical Methods in Computer Graphics, Duksung Univ. Nov. 1. 2006, lbg@dongseo. ac. kr

References • Curves and Surfaces for Computer Aided Geometric Design, Gerald Farin, Academic Press • The NURBS book, Les Piegl and Wayne Tiller, Springer • Spline Methods Drafts, Tom Lyche and Knut Morken • Computer Graphics & Geometric Modeling, Davis Salomon, Springer http: //kowon. dongseo. ac. kr/~lbg/cagd/ Mathematical Methods in Computer Graphics, Duksung Univ. Nov. 1. 2006, lbg@dongseo. ac. kr