Curves, Surfaces and Recursive Subdivision
|
|
- Mark Gibson
- 5 years ago
- Views:
Transcription
1 Department of Computer Sciences Graphics Fall 25 (Lecture ) Curves, Surfaces and Recursive Subdivision Conics: Curves and Quadrics: Surfaces Implicit form arametric form Rational Bézier Forms Recursive Subdivision of Curves Recursive Subdivision of Surfaces The University of Texas at Austin
2 Department of Computer Sciences Graphics Fall 25 (Lecture ) Conic Curves Conic Sections (Implicit form) Ellipse Hyperbola arabola x 2 a 2 + y2 b 2 = a, b > x 2 a 2 y2 b 2 = a, b > y 2 = 4ax a > The University of Texas at Austin 2
3 Department of Computer Sciences Graphics Fall 25 (Lecture ) Conic Sections (arametric form) Ellipse Hyperbola arabola x(t) = a t2 + t 2 y(t) = b 2t ( < t < + ) + t2 x(t) = a + t2 t 2 y(t) = b 2t ( < t < + ) t2 The University of Texas at Austin 3
4 Department of Computer Sciences Graphics Fall 25 (Lecture ) x(t) = at 2 y(t) = 2at ( < t < + ) The University of Texas at Austin 4
5 Department of Computer Sciences Graphics Fall 25 (Lecture ) Constructing Curve Segments Linear blend: Line segment from an affine combination of points (t) = ( t) + t t ( _ t ) The University of Texas at Austin 5
6 Department of Computer Sciences Graphics Fall 25 (Lecture ) Quadratic blend: Quadratic segment from an affine combination of line segments (t) = ( t) + t (t) = ( t) + t 2 2 (t) = ( t) (t) + t (t) 2 2 The University of Texas at Austin 6
7 Department of Computer Sciences Graphics Fall 25 (Lecture ) Cubic blend: Cubic segment from an affine combination of quadratic segments (t) = ( t) + t (t) = ( t) + t 2 2 (t) = ( t) (t) + t (t) 2 (t) = ( t) 2 + t 3 2 (t) = ( t) (t) + t 2 (t) 3 (t) = ( t) 2 (t) + t 2 (t) The University of Texas at Austin 7
8 Department of Computer Sciences Graphics Fall 25 (Lecture ) The pattern should be evident for higher degrees 3 The University of Texas at Austin 8
9 Department of Computer Sciences Graphics Fall 25 (Lecture ) Geometric view (de Casteljau Algorithm): Join the points i by line segments Join the t : ( t) points of those line segments by line segments Repeat as necessary The t : ( t) point on the final line segment is a point on the curve The final line segment is tangent to the curve at t t ( _ ) t _ ) ( t 2 t ( _ t) t 2 The University of Texas at Austin 9
10 Department of Computer Sciences Graphics Fall 25 (Lecture ) Subdivision of olygons Four oint Scheme c j -2 j+ c-3 j+ c-2 j - c j+ j+ c - c j+ c j c c 2 j c j+ j+ c 3 c j -3 c j 2 c j 3 Four point scheme: the filled circles are the level j control points, the filled squares are the level j + control points. For four-point scheme we need to consider only 7 control points; these 7 points completely define the piece of the curve around a control point. We can consider a set of 7 control points on any subdivision level, as we do not care how small our piece of the curve is. Note that we can compute the positions of the seven control points on level j + from the positions of similar seven control points on level j, using a 7 7 submatrix S of the infinite subdivision matrix. The University of Texas at Austin
11 Department of Computer Sciences Graphics Fall 25 (Lecture ) The local subdivision matrix for the four-point scheme is: c j+ 3 c j+ 2 c j+ c j+ c j+ c j+ 2 c j+ 3 = c j 3 c j 2 c j c j c j c j 2 c j 3 The University of Texas at Austin
12 Department of Computer Sciences Graphics Fall 25 (Lecture ) Quadric Surfaces Implicit form arametric form The University of Texas at Austin 2
13 Department of Computer Sciences Graphics Fall 25 (Lecture ) Constructing Surface atches Triangular decasteljau: Join adjacently indexed ijk by triangles Find r : s : t barycentric point in each triangle Join adjacent points by triangles Repeat Final point is the surface point (r, s, t) final triangle is tangent to the surface at (r, s, t) Triangle up/down schemes become tetrahedral up/down schemes roperties: The University of Texas at Austin 3
14 Department of Computer Sciences Graphics Fall 25 (Lecture ) Each boundary curve is a Bézier curve atches will be joined smoothly if pairs of boundary triangles are planar as shown Q 2 2 Q Q 2 The University of Texas at Austin 4
15 Department of Computer Sciences Graphics Fall 25 (Lecture ) Tensor roduct atches Tensor roduct atches: The control polygon is the polygonal mesh with vertices i,j The patch basis functions are products of curve basis functions (s, t) = n n i,j B n i,j (s, t) i= j= where B n i,j (s, t) = Bn i (s)bn j (t) The University of Texas at Austin 5
16 Department of Computer Sciences Graphics Fall 25 (Lecture ) The University of Texas at Austin 6
17 Department of Computer Sciences Graphics Fall 25 (Lecture ) Smoothly Joined atches: 2 3 Q 2 Q 3 Q Q 2 Q 2 Q Q 3 33 Q 3 32 Can be achieved by ensuring that ( i,n i,n ) = β(q i, Qi, ) for β > (and correspondingly for other boundaries) The University of Texas at Austin 7
18 Department of Computer Sciences Graphics Fall 25 (Lecture ) Rendering via Subdivision: Divide up into polygons:. By stepping s =, δ, 2δ,..., t =, γ, 2γ,..., and joining up sides and diagonals to produce a triangular mesh 2. By subdividing and rendering the control polygon The University of Texas at Austin 8
19 Department of Computer Sciences Graphics Fall 25 (Lecture ) Subdivision for olyhedra Regular olyhedra (latonic Solids) Tetrahedron Octahedron Icosahedron Hexahedron (Cube) Dodecahedron The University of Texas at Austin 9
20 Department of Computer Sciences Graphics Fall 25 (Lecture ) Catmull Clark Refinement rule used by Catmull-Clark subdivision scheme is as follows. New vertices are added on each edge and in the center. When connected, 4 new level j + quadrilaterals are produced from the single level j quadrilateral. V j V j 8 V j 7 E j+ 2 V j 2 V j V j 6 E j+ 3 F j+ E j+ E j+ V j+ V j 3 V j 4 V j 5 Catmull-Clark subdivision scheme. Circles are the j level and Squares are the j + level. The vertex rule, edge rule and face rule are shown in the following figure. Each black circle The University of Texas at Austin 2
21 Department of Computer Sciences Graphics Fall 25 (Lecture ) represents a vertex at level j; we compute the position of the vertex at level j + marked by the black square. Note that for the vertex rule, the control vertex with weight 9 6 and the new vertex aren t necessarily aligned as they are in the figure. V j 64 V j V j 7 V j 6 6 V j 8 V j 4 4 V j 8 V j V j V j 6 V j E j+ 3 8 V j F j V j 3 V j 4 V j 5 V j 3 V j 4 V j 2 V j Vertex rule: V j+ = 9 6 V j (V j 2 + V j 4 + V j 6 + V j 8 ) + 64 (V j + V j 3 + V j 5 + V j 7 ) The University of Texas at Austin 2
22 Department of Computer Sciences Graphics Fall 25 (Lecture ) Edge rule: Face rule: E j+ = 3 8 (V j + V j 2 ) + 6 (V j + V j 3 + V j 4 + V j 8 ) F j+ = 4 (V j + V j 2 + V j + V j 8 ) Arbitrary Meshes We have defined Catmull-Clark scheme on quadrilaterals; it can be extended to handle arbitrary polygonal meshes. Observe that if we do one step of refinement, splitting each edge into two and inserting a new vertex for each face (see below Figure), we get a mesh which has only quadrilateral faces. On all other steps of subdivision standard rule described above can be applied. Splitting a hexagon into quadrilaterals. The University of Texas at Austin 22
23 Department of Computer Sciences Graphics Fall 25 (Lecture ) Reading Assignment and News Chapter pages , of Recommended Text. lease also track the News section of the Course Web ages for the most recent Announcements related to this course. ( The University of Texas at Austin 23
Lecture IV Bézier Curves
Lecture IV Bézier Curves Why Curves? Why Curves? Why Curves? Why Curves? Why Curves? Linear (flat) Curved Easier More pieces Looks ugly Complicated Fewer pieces Looks smooth What is a curve? Intuitively:
More informationINF3320 Computer Graphics and Discrete Geometry
INF3320 Computer Graphics and Discrete Geometry More smooth Curves and Surfaces Christopher Dyken, Michael Floater and Martin Reimers 10.11.2010 Page 1 More smooth Curves and Surfaces Akenine-Möller, Haines
More information3D Modeling Parametric Curves & Surfaces. Shandong University Spring 2013
3D Modeling Parametric Curves & Surfaces Shandong University Spring 2013 3D Object Representations Raw data Point cloud Range image Polygon soup Surfaces Mesh Subdivision Parametric Implicit Solids Voxels
More information3D Modeling Parametric Curves & Surfaces
3D Modeling Parametric Curves & Surfaces Shandong University Spring 2012 3D Object Representations Raw data Point cloud Range image Polygon soup Solids Voxels BSP tree CSG Sweep Surfaces Mesh Subdivision
More informationECE 600, Dr. Farag, Summer 09
ECE 6 Summer29 Course Supplements. Lecture 4 Curves and Surfaces Aly A. Farag University of Louisville Acknowledgements: Help with these slides were provided by Shireen Elhabian A smile is a curve that
More informationSurfaces for CAGD. FSP Tutorial. FSP-Seminar, Graz, November
Surfaces for CAGD FSP Tutorial FSP-Seminar, Graz, November 2005 1 Tensor Product Surfaces Given: two curve schemes (Bézier curves or B splines): I: x(u) = m i=0 F i(u)b i, u [a, b], II: x(v) = n j=0 G
More information2D Spline Curves. CS 4620 Lecture 18
2D Spline Curves CS 4620 Lecture 18 2014 Steve Marschner 1 Motivation: smoothness In many applications we need smooth shapes that is, without discontinuities So far we can make things with corners (lines,
More informationComputergrafik. Matthias Zwicker Universität Bern Herbst 2016
Computergrafik Matthias Zwicker Universität Bern Herbst 2016 Today Curves NURBS Surfaces Parametric surfaces Bilinear patch Bicubic Bézier patch Advanced surface modeling 2 Piecewise Bézier curves Each
More informationSubdivision Surfaces
Subdivision Surfaces 1 Geometric Modeling Sometimes need more than polygon meshes Smooth surfaces Traditional geometric modeling used NURBS Non uniform rational B-Spline Demo 2 Problems with NURBS A single
More informationAdvanced Modeling 2. Katja Bühler, Andrej Varchola, Eduard Gröller. March 24, x(t) z(t)
Advanced Modeling 2 Katja Bühler, Andrej Varchola, Eduard Gröller March 24, 2014 1 Parametric Representations A parametric curve in E 3 is given by x(t) c : c(t) = y(t) ; t I = [a, b] R z(t) where x(t),
More informationSubdivision surfaces. University of Texas at Austin CS384G - Computer Graphics Fall 2010 Don Fussell
Subdivision surfaces University of Texas at Austin CS384G - Computer Graphics Fall 2010 Don Fussell Reading Recommended: Stollnitz, DeRose, and Salesin. Wavelets for Computer Graphics: Theory and Applications,
More informationCurves and Surfaces 1
Curves and Surfaces 1 Representation of Curves & Surfaces Polygon Meshes Parametric Cubic Curves Parametric Bi-Cubic Surfaces Quadric Surfaces Specialized Modeling Techniques 2 The Teapot 3 Representing
More informationCurves and Surfaces. Shireen Elhabian and Aly A. Farag University of Louisville
Curves and Surfaces Shireen Elhabian and Aly A. Farag University of Louisville February 21 A smile is a curve that sets everything straight Phyllis Diller (American comedienne and actress, born 1917) Outline
More informationParametric Curves. University of Texas at Austin CS384G - Computer Graphics
Parametric Curves University of Texas at Austin CS384G - Computer Graphics Fall 2010 Don Fussell Parametric Representations 3 basic representation strategies: Explicit: y = mx + b Implicit: ax + by + c
More informationCS354 Computer Graphics Surface Representation IV. Qixing Huang March 7th 2018
CS354 Computer Graphics Surface Representation IV Qixing Huang March 7th 2018 Today s Topic Subdivision surfaces Implicit surface representation Subdivision Surfaces Building complex models We can extend
More informationComputer Graphics Curves and Surfaces. Matthias Teschner
Computer Graphics Curves and Surfaces Matthias Teschner Outline Introduction Polynomial curves Bézier curves Matrix notation Curve subdivision Differential curve properties Piecewise polynomial curves
More informationComputergrafik. Matthias Zwicker. Herbst 2010
Computergrafik Matthias Zwicker Universität Bern Herbst 2010 Today Curves NURBS Surfaces Parametric surfaces Bilinear patch Bicubic Bézier patch Advanced surface modeling Piecewise Bézier curves Each segment
More informationSubdivision Surfaces
Subdivision Surfaces 1 Geometric Modeling Sometimes need more than polygon meshes Smooth surfaces Traditional geometric modeling used NURBS Non uniform rational B-Spline Demo 2 Problems with NURBS A single
More informationParametric Curves. University of Texas at Austin CS384G - Computer Graphics Fall 2010 Don Fussell
Parametric Curves University of Texas at Austin CS384G - Computer Graphics Fall 2010 Don Fussell Parametric Representations 3 basic representation strategies: Explicit: y = mx + b Implicit: ax + by + c
More informationSubdivision curves and surfaces. Brian Curless CSE 557 Fall 2015
Subdivision curves and surfaces Brian Curless CSE 557 Fall 2015 1 Reading Recommended: Stollnitz, DeRose, and Salesin. Wavelets for Computer Graphics: Theory and Applications, 1996, section 6.1-6.3, 10.2,
More informationCS-184: Computer Graphics
CS-184: Computer Graphics Lecture #12: Curves and Surfaces Prof. James O Brien University of California, Berkeley V2007-F-12-1.0 Today General curve and surface representations Splines and other polynomial
More informationPhysically-Based Modeling and Animation. University of Missouri at Columbia
Overview of Geometric Modeling Overview 3D Shape Primitives: Points Vertices. Curves Lines, polylines, curves. Surfaces Triangle meshes, splines, subdivision surfaces, implicit surfaces, particles. Solids
More informationCurves and Surfaces 2
Curves and Surfaces 2 Computer Graphics Lecture 17 Taku Komura Today More about Bezier and Bsplines de Casteljau s algorithm BSpline : General form de Boor s algorithm Knot insertion NURBS Subdivision
More informationSubdivision Curves and Surfaces: An Introduction
Subdivision Curves and Surfaces: An Introduction Corner Cutting De Casteljau s and de Boor s algorithms all use corner-cutting procedures. Corner cutting can be local or non-local. A cut is local if it
More informationKnow it. Control points. B Spline surfaces. Implicit surfaces
Know it 15 B Spline Cur 14 13 12 11 Parametric curves Catmull clark subdivision Parametric surfaces Interpolating curves 10 9 8 7 6 5 4 3 2 Control points B Spline surfaces Implicit surfaces Bezier surfaces
More informationLocal Mesh Operators: Extrusions Revisited
Local Mesh Operators: Extrusions Revisited Eric Landreneau Computer Science Department Abstract Vinod Srinivasan Visualization Sciences Program Texas A&M University Ergun Akleman Visualization Sciences
More informationFrom curves to surfaces. Parametric surfaces and solid modeling. Extrusions. Surfaces of revolution. So far have discussed spline curves in 2D
From curves to surfaces Parametric surfaces and solid modeling CS 465 Lecture 12 2007 Doug James & Steve Marschner 1 So far have discussed spline curves in 2D it turns out that this already provides of
More informationCurves D.A. Forsyth, with slides from John Hart
Curves D.A. Forsyth, with slides from John Hart Central issues in modelling Construct families of curves, surfaces and volumes that can represent common objects usefully; are easy to interact with; interaction
More informationExample: Loop Scheme. Example: Loop Scheme. What makes a good scheme? recursive application leads to a smooth surface.
Example: Loop Scheme What makes a good scheme? recursive application leads to a smooth surface 200, Denis Zorin Example: Loop Scheme Refinement rule 200, Denis Zorin Example: Loop Scheme Two geometric
More informationCurve Corner Cutting
Subdivision ision Techniqueses Spring 2010 1 Curve Corner Cutting Take two points on different edges of a polygon and join them with a line segment. Then, use this line segment to replace all vertices
More informationCurves and Surfaces Computer Graphics I Lecture 9
15-462 Computer Graphics I Lecture 9 Curves and Surfaces Parametric Representations Cubic Polynomial Forms Hermite Curves Bezier Curves and Surfaces [Angel 10.1-10.6] February 19, 2002 Frank Pfenning Carnegie
More informationCS-184: Computer Graphics. Today
CS-84: Computer Graphics Lecture #5: Curves and Surfaces Prof. James O Brien University of California, Berkeley V25F-5-. Today General curve and surface representations Splines and other polynomial bases
More information09 - Designing Surfaces. CSCI-GA Computer Graphics - Fall 16 - Daniele Panozzo
9 - Designing Surfaces Triangular surfaces A surface can be discretized by a collection of points and triangles Each triangle is a subset of a plane Every point on the surface can be expressed as an affine
More informationThe goal is the definition of points with numbers and primitives with equations or functions. The definition of points with numbers requires a
The goal is the definition of points with numbers and primitives with equations or functions. The definition of points with numbers requires a coordinate system and then the measuring of the point with
More informationGrade VIII. Mathematics Geometry Notes. #GrowWithGreen
Grade VIII Mathematics Geometry Notes #GrowWithGreen Polygons can be classified according to their number of sides (or vertices). The sum of all the interior angles of an n -sided polygon is given by,
More informationSung-Eui Yoon ( 윤성의 )
CS480: Computer Graphics Curves and Surfaces Sung-Eui Yoon ( 윤성의 ) Course URL: http://jupiter.kaist.ac.kr/~sungeui/cg Today s Topics Surface representations Smooth curves Subdivision 2 Smooth Curves and
More information2D Spline Curves. CS 4620 Lecture 13
2D Spline Curves CS 4620 Lecture 13 2008 Steve Marschner 1 Motivation: smoothness In many applications we need smooth shapes [Boeing] that is, without discontinuities So far we can make things with corners
More informationUntil now we have worked with flat entities such as lines and flat polygons. Fit well with graphics hardware Mathematically simple
Curves and surfaces Escaping Flatland Until now we have worked with flat entities such as lines and flat polygons Fit well with graphics hardware Mathematically simple But the world is not composed of
More informationParameterization of triangular meshes
Parameterization of triangular meshes Michael S. Floater November 10, 2009 Triangular meshes are often used to represent surfaces, at least initially, one reason being that meshes are relatively easy to
More informationModeling. Simulating the Everyday World
Modeling Simulating the Everyday World Three broad areas: Modeling (Geometric) = Shape Animation = Motion/Behavior Rendering = Appearance Page 1 Geometric Modeling 1. How to represent 3d shapes Polygonal
More informationParameterization. Michael S. Floater. November 10, 2011
Parameterization Michael S. Floater November 10, 2011 Triangular meshes are often used to represent surfaces, at least initially, one reason being that meshes are relatively easy to generate from point
More informationInformation Coding / Computer Graphics, ISY, LiTH. Splines
28(69) Splines Originally a drafting tool to create a smooth curve In computer graphics: a curve built from sections, each described by a 2nd or 3rd degree polynomial. Very common in non-real-time graphics,
More informationCOMPUTER AIDED GEOMETRIC DESIGN. Thomas W. Sederberg
COMPUTER AIDED GEOMETRIC DESIGN Thomas W. Sederberg January 31, 2011 ii T. W. Sederberg iii Preface This semester is the 24 th time I have taught a course at Brigham Young University titled, Computer Aided
More informationCurves and Surfaces for Computer-Aided Geometric Design
Curves and Surfaces for Computer-Aided Geometric Design A Practical Guide Fourth Edition Gerald Farin Department of Computer Science Arizona State University Tempe, Arizona /ACADEMIC PRESS I San Diego
More informationLecture 25: Bezier Subdivision. And he took unto him all these, and divided them in the midst, and laid each piece one against another: Genesis 15:10
Lecture 25: Bezier Subdivision And he took unto him all these, and divided them in the midst, and laid each piece one against another: Genesis 15:10 1. Divide and Conquer If we are going to build useful
More informationGEOMETRIC TOOLS FOR COMPUTER GRAPHICS
GEOMETRIC TOOLS FOR COMPUTER GRAPHICS PHILIP J. SCHNEIDER DAVID H. EBERLY MORGAN KAUFMANN PUBLISHERS A N I M P R I N T O F E L S E V I E R S C I E N C E A M S T E R D A M B O S T O N L O N D O N N E W
More informationCurves & Surfaces. MIT EECS 6.837, Durand and Cutler
Curves & Surfaces Schedule Sunday October 5 th, * 3-5 PM * Review Session for Quiz 1 Extra Office Hours on Monday Tuesday October 7 th : Quiz 1: In class 1 hand-written 8.5x11 sheet of notes allowed Wednesday
More informationSubdivision Curves and Surfaces
Subdivision Surfaces or How to Generate a Smooth Mesh?? Subdivision Curves and Surfaces Subdivision given polyline(2d)/mesh(3d) recursively modify & add vertices to achieve smooth curve/surface Each iteration
More informationComputer Aided Geometric Design
Brigham Young University BYU ScholarsArchive All Faculty Publications 2012-01-10 Computer Aided Geometric Design Thomas W. Sederberg tom@cs.byu.edu Follow this and additional works at: https://scholarsarchive.byu.edu/facpub
More informationSHAPE AND STRUCTURE. Shape and Structure. An explanation of Mathematical terminology
Shape and Structure An explanation of Mathematical terminology 2005 1 POINT A dot Dots join to make lines LINE A line is 1 dimensional (length) A line is a series of points touching each other and extending
More informationCurves & Surfaces. Last Time? Progressive Meshes. Selective Refinement. Adjacency Data Structures. Mesh Simplification. Mesh Simplification
Last Time? Adjacency Data Structures Curves & Surfaces Geometric & topologic information Dynamic allocation Efficiency of access Mesh Simplification edge collapse/vertex split geomorphs progressive transmission
More informationRendering Curves and Surfaces. Ed Angel Professor of Computer Science, Electrical and Computer Engineering, and Media Arts University of New Mexico
Rendering Curves and Surfaces Ed Angel Professor of Computer Science, Electrical and Computer Engineering, and Media Arts University of New Mexico Objectives Introduce methods to draw curves - Approximate
More informationDesign considerations
Curves Design considerations local control of shape design each segment independently smoothness and continuity ability to evaluate derivatives stability small change in input leads to small change in
More informationSpline Surfaces, Subdivision Surfaces
CS-C3100 Computer Graphics Spline Surfaces, Subdivision Surfaces vectorportal.com Trivia Assignment 1 due this Sunday! Feedback on the starter code, difficulty, etc., much appreciated Put in your README
More informationCSE 167: Introduction to Computer Graphics Lecture #13: Curves. Jürgen P. Schulze, Ph.D. University of California, San Diego Fall Quarter 2017
CSE 167: Introduction to Computer Graphics Lecture #13: Curves Jürgen P. Schulze, Ph.D. University of California, San Diego Fall Quarter 2017 Announcements Project 4 due Monday Nov 27 at 2pm Next Tuesday:
More informationCS130 : Computer Graphics Curves (cont.) Tamar Shinar Computer Science & Engineering UC Riverside
CS130 : Computer Graphics Curves (cont.) Tamar Shinar Computer Science & Engineering UC Riverside Blending Functions Blending functions are more convenient basis than monomial basis canonical form (monomial
More informationCurves and Surfaces Computer Graphics I Lecture 10
15-462 Computer Graphics I Lecture 10 Curves and Surfaces Parametric Representations Cubic Polynomial Forms Hermite Curves Bezier Curves and Surfaces [Angel 10.1-10.6] September 30, 2003 Doug James Carnegie
More informationCentral issues in modelling
Central issues in modelling Construct families of curves, surfaces and volumes that can represent common objects usefully; are easy to interact with; interaction includes: manual modelling; fitting to
More information336 Geometry for computer graphics
Index A acute angle, 4 triangle, 11 addition quaternions, 33 vectors, 30 algebra matrices, 2 vectors, 29 alternate exterior angles, 4 interior angles, 4, 86 segment theorem, 183 altitude, see height altitude
More informationCSE 167: Introduction to Computer Graphics Lecture #11: Bezier Curves. Jürgen P. Schulze, Ph.D. University of California, San Diego Fall Quarter 2016
CSE 167: Introduction to Computer Graphics Lecture #11: Bezier Curves Jürgen P. Schulze, Ph.D. University of California, San Diego Fall Quarter 2016 Announcements Project 3 due tomorrow Midterm 2 next
More informationIntroduction to Computer Graphics
Introduction to Computer Graphics 2016 Spring National Cheng Kung University Instructors: Min-Chun Hu 胡敏君 Shih-Chin Weng 翁士欽 ( 西基電腦動畫 ) Data Representation Curves and Surfaces Limitations of Polygons Inherently
More informationLocal Modification of Subdivision Surfaces Based on Curved Mesh
Local Modification of Subdivision Surfaces Based on Curved Mesh Yoshimasa Tokuyama Tokyo Polytechnic University tokuyama@image.t-kougei.ac.jp Kouichi Konno Iwate University konno@cis.iwate-u.ac.jp Junji
More informationCurves. Computer Graphics CSE 167 Lecture 11
Curves Computer Graphics CSE 167 Lecture 11 CSE 167: Computer graphics Polynomial Curves Polynomial functions Bézier Curves Drawing Bézier curves Piecewise Bézier curves Based on slides courtesy of Jurgen
More informationComputer Graphics I Lecture 11
15-462 Computer Graphics I Lecture 11 Midterm Review Assignment 3 Movie Midterm Review Midterm Preview February 26, 2002 Frank Pfenning Carnegie Mellon University http://www.cs.cmu.edu/~fp/courses/graphics/
More informationWe have set up our axioms to deal with the geometry of space but have not yet developed these ideas much. Let s redress that imbalance.
Solid geometry We have set up our axioms to deal with the geometry of space but have not yet developed these ideas much. Let s redress that imbalance. First, note that everything we have proven for the
More informationPolygon Meshes and Implicit Surfaces
CSCI 420 Computer Graphics Lecture 9 Polygon Meshes and Implicit Surfaces Polygon Meshes Implicit Surfaces Constructive Solid Geometry [Angel Ch. 10] Jernej Barbic University of Southern California 1 Modeling
More informationPolygon Meshes and Implicit Surfaces
CSCI 420 Computer Graphics Lecture 9 and Constructive Solid Geometry [Angel Ch. 10] Jernej Barbic University of Southern California Modeling Complex Shapes An equation for a sphere is possible, but how
More informationCurves and Curved Surfaces. Adapted by FFL from CSE167: Computer Graphics Instructor: Ronen Barzel UCSD, Winter 2006
Curves and Curved Surfaces Adapted by FFL from CSE167: Computer Graphics Instructor: Ronen Barzel UCSD, Winter 2006 Outline for today Summary of Bézier curves Piecewise-cubic curves, B-splines Surface
More informationSubdivision Surfaces. Homework 1: Questions on Homework? Last Time? Today. Tensor Product. What s an illegal edge collapse?
Homework 1: Questions/Comments? Subdivision Surfaces Questions on Homework? Last Time? What s an illegal edge collapse? Curves & Surfaces Continuity Definitions 2 3 C0, G1, C1, C 1 a b 4 Interpolation
More informationC 1 Quadratic Interpolation of Meshes
C 1 Quadratic Interpolation of Meshes David Eberly, Geometric Tools, Redmond WA 98052 https://www.geometrictools.com/ This work is licensed under the Creative Commons Attribution 4.0 International License.
More informationSubdivision Surfaces
Subdivision Surfaces CS 4620 Lecture 31 Cornell CS4620 Fall 2015 1 Administration A5 due on Friday Dreamworks visiting Thu/Fri Rest of class Surfaces, Animation, Rendering w/ prior instructor Steve Marschner
More informationAdvanced Graphics. Subdivision Surfaces. Alex Benton, University of Cambridge Supported in part by Google UK, Ltd
Advanced Graphics Subdivision Surfaces Alex Benton, University of Cambridge A.Benton@damtp.cam.ac.uk Supported in part by Google UK, Ltd NURBS patches aren t the greatest NURBS patches are nxm, forming
More informationPlatonic Solids and the Euler Characteristic
Platonic Solids and the Euler Characteristic Keith Jones Sanford Society, SUNY Oneonta September 2013 What is a Platonic Solid? A Platonic Solid is a 3-dimensional object with flat faces and straight edges
More informationFive Platonic Solids: Three Proofs
Five Platonic Solids: Three Proofs Vincent J. Matsko IMSA, Dodecahedron Day Workshop 18 November 2011 Convex Polygons convex polygons nonconvex polygons Euler s Formula If V denotes the number of vertices
More informationIntroduction to Geometry. Computer Graphics CMU /15-662
Introduction to Geometry Computer Graphics CMU 15-462/15-662 Assignment 2: 3D Modeling You will be able to create your own models (This mesh was created in Scotty3D in about 5 minutes... you can do much
More informationSubdivision Surfaces. Homework 1: Questions/Comments?
Subdivision Surfaces Homework 1: Questions/Comments? 1 Questions on Homework? What s an illegal edge collapse? 1 2 3 a b 4 7 To be legal, the ring of vertex neighbors must be unique (have no duplicates)!
More informationINSTRUCTIONS FOR THE USE OF THE SUPER RULE TM
INSTRUCTIONS FOR THE USE OF THE SUPER RULE TM NOTE: All images in this booklet are scale drawings only of template shapes and scales. Preparation: Your SUPER RULE TM is a valuable acquisition for classroom
More informationand the crooked shall be made straight, and the rough ways shall be made smooth; Luke 3:5
ecture 8: Knot Insertion Algorithms for B-Spline Curves and Surfaces and the crooked shall be made straight, and the rough ways shall be made smooth; uke 3:5. Motivation B-spline methods have several advantages
More informationB-spline Curves. Smoother than other curve forms
Curves and Surfaces B-spline Curves These curves are approximating rather than interpolating curves. The curves come close to, but may not actually pass through, the control points. Usually used as multiple,
More informationOn Smooth Bicubic Surfaces from Quad Meshes
On Smooth Bicubic Surfaces from Quad Meshes Jianhua Fan and Jörg Peters Dept CISE, University of Florida Abstract. Determining the least m such that one m m bi-cubic macropatch per quadrilateral offers
More informationCSE 554 Lecture 7: Deformation II
CSE 554 Lecture 7: Deformation II Fall 2011 CSE554 Deformation II Slide 1 Review Rigid-body alignment Non-rigid deformation Intrinsic methods: deforming the boundary points An optimization problem Minimize
More informationThe Essentials of CAGD
The Essentials of CAGD Chapter 6: Bézier Patches Gerald Farin & Dianne Hansford CRC Press, Taylor & Francis Group, An A K Peters Book www.farinhansford.com/books/essentials-cagd c 2 Farin & Hansford The
More informationSubdivision Surfaces. Course Syllabus. Course Syllabus. Modeling. Equivalence of Representations. 3D Object Representations
Subdivision Surfaces Adam Finkelstein Princeton University COS 426, Spring 2003 Course Syllabus I. Image processing II. Rendering III. Modeling IV. Animation Image Processing (Rusty Coleman, CS426, Fall99)
More informationCS3621 Midterm Solution (Fall 2005) 150 points
CS362 Midterm Solution Fall 25. Geometric Transformation CS362 Midterm Solution (Fall 25) 5 points (a) [5 points] Find the 2D transformation matrix for the reflection about the y-axis transformation (i.e.,
More informationInteractive Graphics. Lecture 9: Introduction to Spline Curves. Interactive Graphics Lecture 9: Slide 1
Interactive Graphics Lecture 9: Introduction to Spline Curves Interactive Graphics Lecture 9: Slide 1 Interactive Graphics Lecture 13: Slide 2 Splines The word spline comes from the ship building trade
More informationComputer Graphics 1. Chapter 2 (May 19th, 2011, 2-4pm): 3D Modeling. LMU München Medieninformatik Andreas Butz Computergraphik 1 SS2011
Computer Graphics 1 Chapter 2 (May 19th, 2011, 2-4pm): 3D Modeling 1 The 3D rendering pipeline (our version for this class) 3D models in model coordinates 3D models in world coordinates 2D Polygons in
More informationLECTURE #6. Geometric Modelling for Engineering Applications. Geometric modeling for engineering applications
LECTURE #6 Geometric modeling for engineering applications Geometric Modelling for Engineering Applications Introduction to modeling Geometric modeling Curve representation Hermite curve Bezier curve B-spline
More informationBézier and B-spline volumes Project of Dissertation
Department of Algebra, Geometry and Didactics of Mathematics Faculty of Mathemathics, Physics and Informatics Comenius University, Bratislava Bézier and B-spline volumes Project of Dissertation Martin
More information11/1/13. Polygon Meshes and Implicit Surfaces. Shape Representations. Polygon Models in OpenGL. Modeling Complex Shapes
CSCI 420 Computer Graphics Lecture 7 and Constructive Solid Geometry [Angel Ch. 12.1-12.3] Jernej Barbic University of Southern California Modeling Complex Shapes An equation for a sphere is possible,
More informationComputer Graphics Splines and Curves
Computer Graphics 2015 9. Splines and Curves Hongxin Zhang State Key Lab of CAD&CG, Zhejiang University 2015-11-23 About homework 3 - an alternative solution with WebGL - links: - WebGL lessons http://learningwebgl.com/blog/?page_id=1217
More informationform. We will see that the parametric form is the most common representation of the curve which is used in most of these cases.
Computer Graphics Prof. Sukhendu Das Dept. of Computer Science and Engineering Indian Institute of Technology, Madras Lecture - 36 Curve Representation Welcome everybody to the lectures on computer graphics.
More informationFinal Exam CS 184: Foundations of Computer Graphics! page 1 of 12!
Final Exam CS 184: Foundations of Computer Graphics! page 1 of 12! Student Name:! Class Account Username: Instructions: Read them carefully!! The exam begins at 8:10pm and ends at 10:00pm. You must turn
More informationCARDSTOCK MODELING Math Manipulative Kit. Student Activity Book
CARDSTOCK MODELING Math Manipulative Kit Student Activity Book TABLE OF CONTENTS Activity Sheet for L.E. #1 - Getting Started...3-4 Activity Sheet for L.E. #2 - Squares and Cubes (Hexahedrons)...5-8 Activity
More informationSEMIREGULAR PENTAGONAL SUBDIVISIONS
SEMIREGULAR PENTAGONAL SUBDIVISIONS ERGUN AKLEMAN & VINOD SRINIVASAN Visualization Sciences Program Texas A&M University ZEKI MELEK & PAUL EDMUNDSON Computer Science Department Abstract Triangular and
More informationGeometric Modeling in Graphics
Geometric Modeling in Graphics Part 10: Surface reconstruction Martin Samuelčík www.sccg.sk/~samuelcik samuelcik@sccg.sk Curve, surface reconstruction Finding compact connected orientable 2-manifold surface
More informationSubdivision Surfaces. Homework 1: Last Time? Today. Bilinear Patch. Tensor Product. Spline Surfaces / Patches
Homework 1: Questions/Comments? Subdivision Surfaces Last Time? Curves & Surfaces Continuity Definitions Spline Surfaces / Patches Tensor Product Bilinear Patches Bezier Patches Trimming Curves C0, G1,
More informationToday we will be exploring three-dimensional objects, those that possess length, width, and depth.
Lesson 22 Lesson 22, page 1 of 13 Glencoe Geometry Chapter 11.1 3-D figures & Polyhedra Today we will be exploring three-dimensional objects, those that possess length, width, and depth. In Euclidean,
More informationUNIVERSITY OF CALGARY. Subdivision Surfaces. Advanced Geometric Modeling Faramarz Samavati
Subdivision Surfaces Surfaces Having arbitrary Topologies Tensor Product Surfaces Non Tensor Surfaces We can t find u-curves and v-curves in general surfaces General Subdivision Coarse mesh Subdivision
More informationCS123 INTRODUCTION TO COMPUTER GRAPHICS. Describing Shapes. Constructing Objects in Computer Graphics 1/15
Describing Shapes Constructing Objects in Computer Graphics 1/15 2D Object Definition (1/3) Lines and polylines: Polylines: lines drawn between ordered points A closed polyline is a polygon, a simple polygon
More informationTESSELLATING ALGEBRAIC CURVES AND SURFACES USING A-PATCHES
TESSELLATING ALGEBRAIC CURVES AND SURFACES USING A-PATCHES Curtis Luk and Stephen Mann University of Waterloo, 200 University Ave W., Waterloo, Ontario, Canada cluk@uwaterloo.ca, smann@uwaterloo.ca Keywords:
More information