Computer Graphics for Artists: An Introduction

272 Pages·2008·29.524 MB·English

by  Andrew Paquette (auth.)

Computer Graphics for Artists: An Introduction
Andrew Paquette
Computer Graphics for Artists:
An Introduction
Andrew Paquette
School of Game Architecture and Design
Breda
The Netherlands

ISBN: 978-1-84800-140-4 e-ISBN: 978-1-84800-141-1

DOI: 10.1007/978-1-84800-141-1

British Library Cataloguing in Publication Data
A catalogue record for this book is available from the British Library

Library of Congress Control Number: 2008922190

© Springer-Verlag London Limited 2008

Apart from any fair dealing for the purposes of research or private study, or criticism or review, as permitted
under the Copyright, Designs and Patents Act 1988, this publication may only be reproduced, stored or
transmitted, in any form or by any means, with the prior permission in writing of the publishers, or in the
case of reprographic reproduction in accordance with the terms of licences issued by the Copyright
Licensing Agency. Enquiries concerning reproduction outside those terms should be sent to the publishers.
The use of registered names, trademarks, etc. in this publication does not imply, even in the absence of a
specific statement, that such names are exempt from the relevant laws and regulations and therefore free for
general use.
The publisher makes no representation, express or implied, with regard to the accuracy of the information
contained in this book and cannot accept any legal responsibility or liability for any errors or omissions that
may be made.

All illustrations, unless stated otherwise, © 2007 Andrew Paquette
Cover Illustrations: Front cover: Heaven bound, © 2005 Andrew Paquette
Back cover: Nurbs motorcycle and render by Robert Joosten, freshman IGAD student

Printed on acid-free paper

9 8 7 6 5 4 3 2 1

Springer Science+Business Media
springer.com
Contents

List of Illustrations……………………………………………………………….vii

Introduction……………………………………………………………………….xi

Part I: 3D1: Introduction to 3D Modeling ……………………………………..1

Chapter 1: 3D: What Is It?...................................................................................3

Chapter 2: Clean Geometry…………………………………………………...33

Chapter 3: Measurements……………………………………………………..65

Chapter 4: Design and Reference……………………………………………..79

Chapter 5: Basic Modeling Tools……………………………………………..95

Chapter 6: Resolution………………………………………………………..105

Chapter 7: Texture Coordinates……………………………………………...117

Chapter 8: 3D1: Checklist and Projects……………………………………...135

Part II: 3D2: Optimization and Surfaces…………………………………….141

Chapter 9: Observation………………………………………………………143

Chapter 10: Optimization…………………………………………………….153

Chapter 11: UV Editing……………………………………………………...165

Chapter 12: Nurbs Curves……………………………………………………185

Chapter 13: Nurbs Surfaces………………………………………………….199

v
vi Contents
Chapter 14: Shapes and Topology…………………………………………...223

Chapter 15: Quality Standards……………………………………………….233

Chapter 16: 3D2: Checklist and Projects…………………………………….237

Glossary………………………………………………………………………...243

Sources……..…………………………………………………………………...257
Index……………………………………………………………………………259
List of Illustrations

Frontispiece, The Parcel, com- Fig 1.17 The seven basic ele-
puter rendering ments of CG
Fig 0.1 Piero Della Francesca, Fig 1.18 Orthographic and per-
Brera Altarpiece 1472–1474 spective grids
Fig 0.2 Paolo Uccello, Chalice Fig 1.19 Cube, sphere, and cylin-
1450 der
Fig 0.3 Georges Seurat, Bridge of Fig 1.20 Wireframe display mode
Courbevoie 1886/1887 Fig 1.21 Shaded display mode
Fig 0.4 Power tech engine block Fig 1.22 A pivot
Fig 0.5 Linear perspective Fig 1.23 Vertex translation
Fig 0.6 Stereovision Fig 1.24 Edge translation
Fig 0.7 Lens curvature Fig 1.25 Face extrusion and scale
Fig 0.8 Stephan Martiniere, Fig 1.26 Correctly projected UVs
Shadow in the Summer 2005 Fig 1.27 Incorrectly projected
Fig 0.9 Claude Monet, Impres- UVs
sion, Sunrise 1874 Fig 1.28 Carton pattern
Fig 0.10 Pixels Fig 1.29 Traced carton pattern as
Fig 1.1 Global zero, Armstrong open polygon
on the Moon Fig 1.30 Carton pattern, subdi-
Fig 1.2 World coordinates vided along fold edges
Fig 1.3 2D and 3D coordinate Fig 1.31 Carton pattern with tex-
systems ture applied
Fig 1.4 Right-hand rule Fig 1.32 The folded carton
Fig 1.5 A vertex Fig 1.33 Low level of difficulty
Fig 1.6 Vertices, an edge, and a Fig 1.34 High level of difficulty
face Fig 1.35 Incorrect extrusion
Fig 1.7 A vector Fig 1.36 Correct extrusion
Fig 1.8 A light ray Fig 1.37 Human and fish differ-
Fig 1.9 Transform, rotation, and ence: measurements
scale translation types Fig 1.38 How do you fold along
Fig 1.10 Local axis nonglobal axis?
Fig 1.11 Polygon, texmap, and Fig 1.39 By rotating model so
mapped polygon that axis is aligned with global axis
Fig 1.12 How a texture map is at- Fig 1.40 Two examples of UV
tached to a polygon layouts
Fig 1.13 Necessity of light Fig 2.1 A cobweb
Fig 1.14 Normals and averaged Fig 2.2 Triangle count
normals Fig 2.3 Shared, nonshared, and
Fig 1.15 Photon through a pipe: coincident vertices
how normals behave Fig 2.4 A spike
Fig 1.16 Reversed normals, as Fig 2.5 A bow-tie face
seen in mirror Fig 2.6 Smoothing error
vii
viii List of Illustrations
Fig 2.7 Floating face Fig 3.8 Measuring the angle of a
Fig 2.8 Separated faces mandible
Fig 2.9 Self-penetration Fig 3.9 Radial breakdown of a
Fig 2.10 Origin offset carton
Fig 2.11 Nonplanar quads Fig 4.1 Floss container and horse
Fig 2.12 Distorted polygons chestnut
Fig 2.13 Reversed normals Fig 4.2 Three dolls
Fig 2.14 A superfluous row of Fig 4.3 Three Etruscan vases
vertices Fig 4.4 Photo reference mosaic
Fig 2.15 Misaligned texture Fig 4.5 Schematic view, court-
Fig 2.16 N-gons house
Fig 2.17 Missing faces from a Fig 4.6 Render, courthouse
milk carton Fig 4.7 Rear derailleur assembly
Fig 2.18 Extrusion error at corner Fig 4.8 Front derailleur assembly
Fig 2.19 Aspect ratio Fig 4.9 Rear hub, schematic
Fig 2.20 Edge layout view
Fig 2.21 Lamina face Fig 4.10 Brake lever, schematic
Fig 2.22 Hidden edges view
Fig 2.23 Duplicate edges Fig 4.11 Label textures
Fig 2.24 Coincident faces Fig 4.12 Material schedule,
Fig 2.25 Geometry gap (in Death courthouse
Valley) Fig 4.13 Errors in character pro-
Fig 2.26 Hole and nonhole duction sketch
polysets Fig 4.14 Model sheet, Dexter
Fig 2.27 Nonmanifold geometry Green
Fig 2.28 Dense, unmotivated ver- Fig 5.1 Basic modeling tool
tices Fig 5.2 Primitive modeling, a
Fig 2.29 Ragged edge floss container
Fig 2.30 Isolated vertex Fig 5.3 Adding vertices
Fig 2.31 Locked normals Fig 5.4 Deleting, collapsing, cut-
Fig 2.32 Renumbered vertices ting, and beveling
Fig 2.33 Zero edge-length face Fig 5.5 Booleans
Fig 2.34 Magnifying glass Fig 5.6 Infinite sampling points
Fig 2.35 Hierarchy example Fig 5.7 Spline-based surface
Fig 3.1 Measurements, ruler and creation
carton Fig 6.1 Roses
Fig 3.2 Robert Wadlow and Fig 6.2 Kneaded eraser, polyset
brother, the difference 150% makes detail limits
Fig 3.3 Giovanni Bellini, St Fig 6.3 High- and low-resolution
Francis in the Desert 1480 character heads
Fig 3.4 Measurement types Fig 6.4 Subdivision of geometry
Fig 3.5 Geometric subdivision for texturing
Fig 3.6 Measuring instruments Fig 6.5 Curve detail, hub and
Fig 3.7 Lens length skewer
List of Illustrations ix
Fig 6.6 How polygons are trans- Fig 7.24 3D paint on edited cubic
lated into pixels projection
Fig 6.7 Guardian, example of Fig 9.1 Lineup
high-resolution graphics Fig 9.2 Call to Prayer, observa-
Fig 6.8 Hidden triangles tion example
Fig 7.1 Cannon Fig 9.3 Schematic-level observa-
Fig 7.2 Cube and default coordi- tion skill
nates Fig 9.4 Strong observation skill
Fig 7.3 Cylinder and default co- Fig 9.5 Ahab, animation model
ordinates sheet
Fig 7.4 Sphere and default coor- Fig 9.6 Shallow cranium
dinates Fig 9.7 Gradient(s)
Fig 7.5 Many seams, good tex- Fig 10.1 High-resolution bicycle
ture layout render
Fig 7.6 Reference map: faces Fig 10.2 Low-resolution bicycle
Fig 7.7 Reference map: type render
Fig 7.8 No distortion Fig 10.3 Hard angles cannot be
Fig 7.9 Distorted UVs removed
Fig 7.10 Distorted polygons Fig 10.4 Bicycle seat, 3D pixels
Fig 7.11 Correctly projected UVs Fig 10.5 Multiple cannon, part
on distorted face detail
Fig 7.12 Default sphere UVs and Fig 10.6 Incised detail
texture Fig 10.7 Low-resolution auto
Fig 7.13 Default sphere, sawtooth Fig 10.8 One thousand triangle
projection bicycle
Fig 7.14 Measuring for Mercator Fig 10.9 Power of silhouettes
projection Fig 11.1 Textured giant crossbow
Fig 7.15 Maximum tiling, Merca- Fig 11.2 Box projection, lemons
tor projection and apples
Fig 7.16 Untiled Mercator projec- Fig 11.3 Reference cube
tion Fig 11.4 Projection within a ref-
Fig 7.17 Scaled untiling Mercator erence cube
projection Fig 11.5 Stretched to fit legal UV
Fig 7.18 Two proportionate space
spherical projections Fig 11.6 Rotate mapping plane to
Fig 7.19 Six proportionate planar fit object
projections Fig 11.7 Multipart object map-
Fig 7.20 Geodesic layout texture ping solution
map Fig 11.8 Poor coordinates on
Fig 7.21 Geodesic UVs and lofted curve
sphere with texture Fig 11.9 Good coordinates on
Fig 7.22 Unedited cubic projection lofted curve
Fig 7.23 Edited cubic projection Fig 11.10 Texturing a knot
x List of Illustrations
Fig 11.11 Texture alignment and Fig 13.2 Like glass and rubber:
backward UVs polys and nurbs
Fig 11.12 Rotated texture map to Fig 13.3 Plane to torus transfor-
match misaligned UVs mation
Fig 11.13 Distorted UVs on char- Fig 13.4 One isoparm at a time
acter at shoulder joint Fig 13.5 Multiple patches re-
Fig 11.14 Seam decision quired due to branching detail
Fig 11.15 Overlapping UVs Fig 13.6 Nurbs plane transforms
Fig 11.16 Nonoverlapping UVs into simple auto
Fig 11.17 Grouping can cause Fig 13.7 Nurbs display is simple
mess in texture editor Fig 13.8 Nurbs starfish, odd
Fig 11.18 Character mapping number of branches
layout Fig 13.9 Triangle and odd num-
Fig 11.19 How do you map a bered parallelogram intersection
posed hand? Fig 13.10 Nonright angle corners,
Fig 11.20 Packing UVs and the same with a trim
Fig 11.21 High-resolution texture Fig 13.11 Two trims
treatment Fig 13.12 Revolve and planes
Fig 11.22 Calculating ideal tex- Fig 13.13 Three-curve surface
map size, three materials Fig 13.14 Curve direction is good
Fig 11.23 Calculating ideal tex- Fig 13.15 Curve direction is not
map size, UV layout good
Fig 11.24 Calculating ideal tex- Fig 13.16 Battle robot head, built
map size, scaled maps from curves
Fig 11.25 Calculating ideal tex- Fig 13.17 Skewer lever, how it
map size, overlapping UVs was built
Fig 12.1 Y-foil rear hub and Fig 13.18 Cast powdered metal
chain rings parts, a real modeler’s challenge
Fig 12.2 A nurbs curve Fig 13.19 Multipatch chain ring
Fig 12.3 Two curves, matching Fig 13.20 Curve detail in chain
tangents rings
Fig 12.4 Two curves, not tangent Fig 13.21 Nurbs normals
Fig 12.5 Tangent surfaces Fig 13.22 Nurbs to poly conversion
Fig 12.6 Curvature continuous Fig 13.23 Distorted embedded
Fig 12.7 Projecting a curve and coordinates on a patch
trim Fig 14.1 Möbius strip
Fig 12.8 Intersecting curves Fig 14.2 Four-sided primitives
Fig 12.9 Nonintersecting curves Fig 14.3 Nurbs deformability
Fig 12.10 Curve tangent to curve Fig 14.4 Three-holed primitive
Fig 12.11 Curve simplification Fig 14.5 2D and 3D space, how it
Fig 12.12 Nontangent and tan- affects topology
gent surface Fig 14.6 Render of skewer lever
Fig 13.1 Nurbs jeep Fig 14.7 An artist sketches