Kansas State University Department of Computing and Information Sciences CIS 736: Computer Graphics Wednesday, February 9, 2000 William H. Hsu Department of Computing and Information Sciences, KSU Readings: Sections 11.1, , Foley et al (Reference) Appendix A.9, , , Hearn and Baker 2 e (Reference) ,10.6, Angel 2 e Lecture 7 Clipping Concluded; Introduction to Curve Representations

Kansas State University Department of Computing and Information Sciences CIS 736: Computer Graphics Lecture Outline Readings –Sections 11.1, , Foley et al –Optional references: Hearn and Baker 2 e, Angel 2 e Quick Review: 3D Viewing –3D view volume –??? Clipping (Concluded) –??? Introduction to Curve Representations –What are cubic curves? –How would we use them to represent surfaces? –Read about polygon meshes, Bézier curves, B-splines for next time! Next Lecture: Cubic Curves and Surfaces

Kansas State University Department of Computing and Information Sciences CIS 736: Computer Graphics Quick Review: 3D View Volume 3 Components –Project proposal (20%, 50 points) –Implementation (50%, 125 points) –Final report (30%, 75 points) Project Proposal (Due 02/14/2000) –1-3 page description of project topic, plan –Guidelines: next (suggested topics, tools to appear on CIS 736 course web page) –See: implementation practicum links (Brown, Cornell, UNC, others) on 736 page Implementation –Students choice of programming language –Guidelines: next Wednesday (and on 736 page) Final Report –4-6 page report on implementation, experimental results, interpretation –Peer-reviewed (does not determine grade) –Reviews graded (short report worth 60 points, reviews worth 15 points)

Kansas State University Department of Computing and Information Sciences CIS 736: Computer Graphics Quick Review: From Perspective to Parallel Perspective-to-Parallel Viewing Transformation –??? Why Is This Important? –??? ??? –??? ??? –??? –Reviews graded (short report worth 60 points, reviews worth 15 points)

Kansas State University Department of Computing and Information Sciences CIS 736: Computer Graphics Clipping

Kansas State University Department of Computing and Information Sciences CIS 736: Computer Graphics Clipping Lines [1]: Simultaneous Equations

Kansas State University Department of Computing and Information Sciences CIS 736: Computer Graphics Clipping Lines [2]: Parametric Equations

Kansas State University Department of Computing and Information Sciences CIS 736: Computer Graphics Clipping Polygons

Kansas State University Department of Computing and Information Sciences CIS 736: Computer Graphics Clipping Curves, Text, and Windows

Kansas State University Department of Computing and Information Sciences CIS 736: Computer Graphics Clipping in 3D [1]: Extending Cohen-Sutherland

Kansas State University Department of Computing and Information Sciences CIS 736: Computer Graphics Clipping in 3D [2]: Extending Liang-Barsky

Kansas State University Department of Computing and Information Sciences CIS 736: Computer Graphics Quick Review: Specifying an Arbitrary 3D View

Kansas State University Department of Computing and Information Sciences CIS 736: Computer Graphics {Intro to Curves}

Kansas State University Department of Computing and Information Sciences CIS 736: Computer Graphics {Intro to Curves}

Kansas State University Department of Computing and Information Sciences CIS 736: Computer Graphics Course Project: More Guidelines 3 Components –Project proposal (20%, 50 points) –Implementation (50%, 125 points) –Final report (30%, 75 points) Project Proposal (Due 02/14/2000) –1-3 page description of project topic, plan –Guidelines: next (suggested topics, tools to appear on CIS 736 course web page) –See: implementation practicum links (Brown, Cornell, UNC, others) on 736 page Implementation –Students choice of programming language –Guidelines: next Wednesday (and on 736 page) Final Report –4-6 page report on implementation, experimental results, interpretation –Peer-reviewed (does not determine grade) –Reviews graded (short report worth 60 points, reviews worth 15 points)

Kansas State University Department of Computing and Information Sciences CIS 736: Computer Graphics Course Project: Suggested Topics 3 Components –Project proposal (20%, 50 points) –Implementation (50%, 125 points) –Final report (30%, 75 points) Project Proposal (Due 02/14/2000) –1-3 page description of project topic, plan –Guidelines: next (suggested topics, tools to appear on CIS 736 course web page) –See: implementation practicum links (Brown, Cornell, UNC, others) on 736 page Implementation –Students choice of programming language –Guidelines: next Wednesday (and on 736 page) Final Report –4-6 page report on implementation, experimental results, interpretation –Peer-reviewed (does not determine grade) –Reviews graded (short report worth 60 points, reviews worth 15 points)

Kansas State University Department of Computing and Information Sciences CIS 736: Computer Graphics Terminology Review: Normalizing Transformations –N’ per = M · S per · SH par · T(–PRP) · R · T(–VRP) (Equation 6.49, FVD) –M: Line Clipping: Determining Parts of Line Segment Primitives to Display –E Division of plane into 9 regions with (4-bit) outcodes Testing endpoints of line segment –Parametric clipping: line / rectangle intersection using parametric equation Cyrus-Beck: general convex 3D polyhedron Liang-Barsky: more efficient, specialized variant (upright 2D, 3D clip regions) Clipping in 3D –Cuboid: truncated viewing pyramid used to clip after N par –Frustum: truncated viewing pyramid Cubic Curves

Kansas State University Department of Computing and Information Sciences CIS 736: Computer Graphics Summary Points