Introduction to Computer Graphics: A Practical Learning Approach

417 Pages·2015·7.181 MB·English

by  Fabio Ganovelli;Massimiliano Corsini;Sumanta Pattanaik;Marco di Benedetto

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FABIO GANOVELLI IK • NOV Introduction to
MASSIMILIANO CORSINI DI BE ELLI •
SUMANTA PATTANAIK NE C COMPUTER
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MARCO DI BENEDETTO E R
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Introduction to Computer Graphics: A Practical Learning Approach PT
guides you in developing your own interactive graphics application.
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The authors show step by step how to implement computer a
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graphics concepts and theory using the EnvyMyCar (NVMC) tD A Practical Learning Approach
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use the WebGL graphics API to develop NVMC, a simple, aC
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interactive car racing game. T
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Each chapter focuses on a particular computer graphics aspect, eO
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such as 3D modeling and lighting. The authors help you under- r
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stand how to handle 3D geometric transformations, texturing, T
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complex lighting effects, and more. This practical approach nO
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• Puts computer graphics theory into practice by developing an
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• Enables you to experiment with the concepts in a practical setting R

• Uses WebGL for code examples, with the code available online G
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• Requires knowledge of general programming and basic notions of HTML
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and JavaScript
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K12432
ISBN: 978-1-4398-5279-8
FABIO GANOVELLI • MASSIMILIANO CORSINI
90000

SUMANTA PATTANAIK • MARCO DI BENEDETTO
9 781439 852798
Computer Graphics

Fabio Ganovelli
MassiMiliano Corsini
suManta Pattanaik
MarCo Di beneDetto
Boca Raton London New York
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Version Date: 20140714
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To Reni
F. Ganovelli
To my grandmother, my parents and my wife
M. Corsini
To my parents
S. Pattanaik
To my family
M. Di Benedetto

Contents
List of Figures xvii
List of Listings xxvii
Preface xxxi
1 What Computer Graphics Is 1
1.1 Application Domains and Areas of Computer Graphics . . . 1
1.1.1 Application Domains . . . . . . . . . . . . . . . . . . . 2
1.1.2 Areas of Computer Graphics . . . . . . . . . . . . . . 2
1.2 Color and Images . . . . . . . . . . . . . . . . . . . . . . . . 5
1.2.1 The Human Visual System (HVS) . . . . . . . . . . . 5
1.2.2 Color Space . . . . . . . . . . . . . . . . . . . . . . . . 6
1.2.2.1 CIE XYZ . . . . . . . . . . . . . . . . . . . . 8
1.2.2.2 Device-Dependent and Device-Independent
Color Space. . . . . . . . . . . . . . . . . . . 9
1.2.2.3 HSL and HSV . . . . . . . . . . . . . . . . . 10
1.2.2.4 CIELab . . . . . . . . . . . . . . . . . . . . . 11
1.2.3 Illuminant . . . . . . . . . . . . . . . . . . . . . . . . . 12
1.2.4 Gamma . . . . . . . . . . . . . . . . . . . . . . . . . . 13
1.2.5 Image Representation . . . . . . . . . . . . . . . . . . 13
1.2.5.1 Vector Images . . . . . . . . . . . . . . . . . 13
1.2.5.2 Raster Images . . . . . . . . . . . . . . . . . 14
1.3 Algorithms to Create a Raster Image from a 3D Scene . . . 17
1.3.1 Ray Tracing . . . . . . . . . . . . . . . . . . . . . . . . 17
1.3.2 Rasterization-Based Pipeline . . . . . . . . . . . . . . 20
1.3.3 Ray Tracing vs Rasterization-Based Pipeline . . . . . 21
1.3.3.1 Ray Tracing Is Better . . . . . . . . . . . . . 21
1.3.3.2 Rasterization Is Better . . . . . . . . . . . . 22
2 The First Steps 23
2.1 The Application Programming Interface . . . . . . . . . . . . 23
2.2 The WebGL Rasterization-Based Pipeline . . . . . . . . . . . 25
2.3 Programming the Rendering Pipeline: Your First Rendering 28
2.4 WebGL Supporting Libraries . . . . . . . . . . . . . . . . . . 40
vii
viii Contents
2.5 Meet NVMC . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
2.5.1 The Framework . . . . . . . . . . . . . . . . . . . . . . 41
2.5.2 The Class NVMC to Represent the World . . . . . . . 42
2.5.3 A Very Basic Client . . . . . . . . . . . . . . . . . . . 42
2.5.4 Code Organization . . . . . . . . . . . . . . . . . . . . 48
3 How a 3D Model Is Represented 51
3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
3.1.1 Digitalization of the Real World . . . . . . . . . . . . 52
3.1.2 Modeling . . . . . . . . . . . . . . . . . . . . . . . . . 52
3.1.3 Procedural Modeling . . . . . . . . . . . . . . . . . . . 53
3.1.4 Simulation . . . . . . . . . . . . . . . . . . . . . . . . 53
3.2 Polygon Meshes . . . . . . . . . . . . . . . . . . . . . . . . . 53
3.2.1 Fans and Strips . . . . . . . . . . . . . . . . . . . . . . 54
3.2.2 Manifoldness . . . . . . . . . . . . . . . . . . . . . . . 54
3.2.3 Orientation . . . . . . . . . . . . . . . . . . . . . . . . 55
3.2.4 Advantages and Disadvantages . . . . . . . . . . . . . 56
3.3 Implicit Surfaces . . . . . . . . . . . . . . . . . . . . . . . . . 57
3.3.1 Advantages and Disadvantages . . . . . . . . . . . . . 58
3.4 Parametric Surfaces . . . . . . . . . . . . . . . . . . . . . . . 58
3.4.1 Parametric Curve. . . . . . . . . . . . . . . . . . . . . 59
3.4.2 B´ezier Curves . . . . . . . . . . . . . . . . . . . . . . . 59
3.4.2.1 Cubic B´ezier Curve . . . . . . . . . . . . . . 61
3.4.3 B-Spline Curves . . . . . . . . . . . . . . . . . . . . . 63
3.4.4 From Parametric Curves to Parametric Surfaces . . . 64
3.4.5 B´ezier Patches . . . . . . . . . . . . . . . . . . . . . . 66
3.4.6 NURBS Surfaces . . . . . . . . . . . . . . . . . . . . . 67
3.4.7 Advantages and Disadvantages . . . . . . . . . . . . . 67
3.5 Voxels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
3.5.1 Rendering Voxels . . . . . . . . . . . . . . . . . . . . . 69
3.5.2 Advantages and Disadvantages . . . . . . . . . . . . . 70
3.6 Constructive Solid Geometry (CSG) . . . . . . . . . . . . . . 70
3.6.1 Advantages and Disadvantages . . . . . . . . . . . . . 71
3.7 Subdivision Surfaces . . . . . . . . . . . . . . . . . . . . . . . 71
3.7.1 Chaikin’s Algorithm . . . . . . . . . . . . . . . . . . . 71
3.7.2 The 4-Point Algorithm . . . . . . . . . . . . . . . . . . 72
3.7.3 Subdivision Methods for Surfaces . . . . . . . . . . . . 73
3.7.4 Classification . . . . . . . . . . . . . . . . . . . . . . . 73
3.7.4.1 Triangular or Quadrilateral . . . . . . . . . . 73
3.7.4.2 Primal or Dual . . . . . . . . . . . . . . . . . 73
3.7.4.3 Approximation vs Interpolation . . . . . . . 74
3.7.4.4 Smoothness . . . . . . . . . . . . . . . . . . . 75
3.7.5 Subdivision Schemes . . . . . . . . . . . . . . . . . . . 75
3.7.5.1 Loop Scheme . . . . . . . . . . . . . . . . . . 76
3.7.5.2 Modified Butterfly Scheme . . . . . . . . . . 76