《计算机辅助几何造型技术》1

计算机辅助几何造型技术主讲教师：秦开怀教授、博导qkh-dcs@所在单位：清华大学计算机科学与技术系 时间：2007年9月~2008年1月Textbooks/ReferencesJ. Hoschek& D. Lasser, Fundamentals of Computer Aided Geometric Design A K Peters Computer Aided Geometric Design, A K Peters, Ltd, Massachusetts, 1993.David F Rogers Introduction to NURBS Morgan David F Rogers,Introduction to NURBS, Morgan Kaufmann,2001.L Piegl&W Tiller The NURBS Book(2L. Piegl & W. Tiller, The NURBS Book (2nd Edition), Springer-Verlag Berlin Heidelberg, NewYork, 1997.York1997Carl deBoor, A Practical Guide to Splines, New York, Springer Verlag, 1978.York Springer-Verlag1978(Continued)M. E. Mortenson, Geometric Modeling , J h W l &S I 1985John Waley & Sons, Inc., 1985. G. Farin, Curves and Surfaces for ,Computer Aided Geometric Design (5th Edition), Elsevier Inc., 2002.(李双喜译，),,(CAGD 曲线曲面，科学出版社，2006）E J Stollnitz T DeRose &D H Salesin E. J. Stollnitz, T. DeRose & D. H. Salesin, Wavelets for Computer Graphics, Theory & Morgan Kaufmann PublishersApplications , Morgan Kaufmann Publishers, Inc., San Francisco, 1996.(Continued)Denis Zorin & Peter Schroder, Subdivision for M d li d A i ti SIGGRAPH 2000Modeling and Animation , SIGGRAPH 2000 Course Notes #23, 2000. R. Barzel, Physically-Based Modeling for Computer Graphics, A Structured Approach,Academic Press, Inc., San Diego, 1992.D. N. Metaxas, Physic-Based Deformable ,yModels, Applications to Computer Vision, Graphics & Medical Imaging , Kluwer Academicp g g ,Publishers, Massachusetts, 1997.(Continued)Donald Hearn & M.Pauline Baker, C t G hi ith O GL (Thi d Computer Graphics with OpenGL (Third Edition), Pearson Education, 2004 (中译本赫恩等著本：赫恩等著, 蔡士杰等译,《计算机图形学（第三版）》, 电子工业出版社, 200506)2005-06.) J. D. Foley, et al, Computer Graphics: y,,p pPrinciples & Practice (2nd Edition in C),Addison-Wesley, Reading, MA, 1996.y,g,,G di P li Grading PolicyThree assignments 30%Discussions/learning in classroom 5% One project substituting for the final p j g examination 65%R kRemarksThe three assignment is to be completed individually on yourself, but discussions among fellow students areyourself but discussions among fellow students areallowed.The project substitutes for the final examination Two The project substitutes for the final examination. Twostudents can work together as a group.Absolutely no sharing or copying of any code for both Absolutely no sharing or copying of any code for boththe assignments and the project! Offenders will be givena failure grade and the case will be reported to theg pdepartment.You are welcome to turn off your mobile phone before You are welcome to turn off your mobile phone beforeattending lectures.This course concentrates on seven main issues:i iNURBS curves and surfaces (including Bezier, B-spline curves and surfaces)gTriangular surfacesGordon-Coons surfacesSubdivision surfaces of arbitrary topologySubdivision surfaces of arbitrary topologyThe 2nd generation wavelets for multi-resolution modelingmodelingSolid modelingNew technology for geometric modelingContents of This Course1.Introduction2.∆Mathematic BasicsAffine mapsAffine mapsDivided differenceFunction spaceGeometric basics from curves and surfaces 3.∆Interpolatory Polynomial SplinesHermite interpolationHermite interpolationContents of This Course Contents of This Course (Continued)Quadric polynomial spline curvesCubic polynomial spline curvesSolving a linear system of equations with a g y q tridiagonal coefficient matrix Cubic parametric spline curves Cubic parametric spline curves4.*Bezier Curves and Surfaces Bezier curves defined by edge vectorsBernstein-Bezier curvesProperties of Bernstein-Bezier curves(Continued)De Casteljau algorithmDi t ti f B iDiscrete generation of Bezier curvesDegree elevation of Bezier curvesD d i f B iDegree reduction of Bezier curvesBezier spline curvesBezier interpolation curvesMatrix formula of Bezier curvesRational Bezier curvesProduct & inner product of Bezier curves Bezier surfaces(Continued)5.*B-spline Curves and SurfacesB-spline basis functions and their p ppropertiesB-spline curvesOpen curves and knot vectorsOpen curves and knot vectorsUniform B-spline curvesEndpoint interpolating B spline curves Endpoint interpolating B-spline curvesClosed B-spline curves(Continued)Chaikin algorithmDe Boor algorithmInserting knots in B-spline curves Inserting knots in B spline curvesBoehm algorithmOlso algorithmGeneral knot insertion for B-spline curvesDegree elevation of B-spline curves Degree elevation of B-spline curvesMarsden identity and recursive degree elevationPrautzsch algorithm(Continued)Arbitrarily high degree elevation for B-spline curvesDegree reduction of B-spline curvesB-spline surfacesInterpolating B-spline curves and p g p surfaces Matrix formulas of B-spline curves and Matrix formulas of B spline curves and surfaces(Continued)Matrix formula of uniform B_spline curvesMatrix formula of non-uniform B_splines Inner product of B-spline curvesGeneralized Marsden identityB-spline curve productInner product of B-spline basis functionsInner product of B-spline curves6.*NURBS Curves and SurfacesNURBS curvesNURBS curvesRepresenting conics using NURBS(Continued)Parameterization of curvesfNURBS surfacesRepresenting quadrics using NURBS surfacesfInterpolating NURBS curves and surfaces 7.Blossoming PrincipleLooking at de Casteljau algorithm from a Looking at de Casteljau algorithm from a blossoming point of viewKnot insertion from a blossoming point of Knot insertion from a blossoming point of view(Continued)Generating de Boor points based on the blossoming principleblossoming principleDegree raising of B-spline curves by blossoming8.* Triangular SurfacesBarycentric coordinatesgTriangular Bezier surfacesContinuity conditions for triangular Bezier ppatchesRational Triangular surfaces(Continued)9.*Gordon-Coons SurfacesCoons surfacesGordon-Coons surfaces on rectanglesGordon-Coons surfaces on triangles0Subd s o Su a s o b a y 10.*Subdivision Surfaces of ArbitraryTopologyCatmull-Clark surfacesCatmull-Clark surfacesDoo-Sabin surfacesContinuity of uniform subdivision surfaces Continuity of uniform subdivision surfacesNon-uniform subdivision surfaces(Continued)Convergence and continuity of non-uniform subdivision surfaces11.*The 2nd Generation Wavelets forMulti-resolution modelingMulti-resolution modelingB-spline wavelets for Multi-resolution modeling Endpoint interpolating B-spline wavelets Endpoint interpolating B-spline waveletsArbitrary Non-uniform B-spline waveletsB-spline wavelets with constraintsB spline wavelets with constraintsSubdivision-based Surface waveletsLoop Subdivision WaveletsCatmull-Clark Subdivision Wavelets√3-subdivision-based Bi-orthogonal Wavelets(Continued)12.∆Scattered Data Interpolation13.*Intersections of Curves and Surfaces14.Solid Modeling14*Solid Modeling15.Parameterization Modeling for ShapeDesign and Feature-based Modeling 16.New Technology for Geometric 16.*New Technology for GeometricModelingHierarchical B splinesHierarchical B-splinesPhysics-based modelingContents of This Course Contents of This Course (Continued)Modeling fractalized scenes (mountains,f lowers etc.)Particle system for modeling fires, clouds, water, forests etc.1.Introduction1. IntroductionSome Applications of CAGDRepresentation of large data setsVisualizing productsAutomatically producing sectionalAutomatically producing sectional drawingsModeling surfaces arising inModeling surfaces arising in construction of cars, ships & airplanesDesigning pipe systems, e.g. in chemical plants(continued)Drawing marine charts and city and relief i h maps in cartographyProduction and quality control, e.g. in q y ,g the sewing machine, textile and shoe industriesPlanning and controlling surgery Creating images in advertising television Creating images in advertising, television and film industries(continued)Constructing virtual environmentsDescribing robot paths and controlling their movementstheir movementsControlling milling machines used in manufacturingCurve modeling with constrained B-spline wavelets 保特征点的多分辨率曲线造型29曲线的多分辨率分段无缝表示30细分曲面带约束的样条曲面小波左图是采用经典B 样条曲面小波分片多分辨率表示的结果,右图是采用带约束B 的样条曲面小波分片多分辨率表示的结果,其中约束施加在接合线处。