Holistic Game Development with Unity. An All-in-One Guide to Implementing Game Mechanics, Art, Design and Programming

467 Pages·2017·89.2 MB·English

by  Penny de Byl

Holistic Game Development
with Unity
An All-in-One Guide to Implementing
Game  Mechanics, Art, Design and Programming
Second Edition

Penny de Byl is a professor of interactive multimedia and games at Bond University in Australia. An award-winning
teacher, Penny has researched and taught computer science, computer graphics, and game development at top-
ranked universities for over 20 years. Author of two books on artificial intelligence programming for computer
games, and winner of the 2011 Unity Technologies’ Unity Mobile Generation Education Giveaway, Penny also hosts
the popular Unity development YouTube channel, Holistic3d.

Holistic Game Development
with Unity

An All-in-One Guide to I mplementing
Game  Mechanics, Art, Design and P rogramming
Second Edition

Penny de Byl
CRC Press
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Library of Congress Cataloging‑in‑Publication Data
Library of Congress Cataloging‑in‑Publication Data
Names: De Byl, Penny, author.
Names: De Byl, Penny, author. Title: Holistic game development with unity an all-in-one guide to
Title: Holistic game development with unity an all-in-one guide to implementing game mechanics, art, design and programming / Penny de Byl.
implementing game mechanics, art, design, and programming / Penny de Byl. Description: 2nd edition. | Boca Raton, FL : Taylor & Francis, 2017. |
Description: 2nd edition. | Boca Raton, FL : Taylor & Francis, 2017. | Includes index.
Includes index. Identifiers: LCCN 2016043693| ISBN 9781138888791 (hardback : alk. paper) |
Identifiers: LCCN 2016043693| ISBN 9781138888791 (hardback : alk. paper) | ISBN 9781138888784 (pbk. : alk. paper)
ISBN 9781138888784 (pbk. : alk. paper) Subjects: LCSH: Computer games--Programming. | Unity (Electronic resource) |
Subjects: LCSH: Computer games--Programming. | Unity (Electronic resource) | Video games--Design.
Video games--Design. Classification: LCC QA76.76.C672 B335 2017 | DDC 794.8/1526--dc23
Classification: LCC QA76.76.C672 B335 2017 | DDC 794.8/1526--dc23 LC record available at https://lccn.loc.gov/2016043693
LC record available at https://lccn.loc.gov/2016043693
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Contents
Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xv
Chapter 1: The Art of Programming Mechanics . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1 Introduction ............................................ 1
1.2 Programming on the Right Side of the Brain .............. 3
1.3 Creating Art from the Left Side of the Brain .............. 8
1.3.1 Point ......................................... 9
1.3.2 Line .......................................... 9
1.3.3 Shape..........................................10
1.3.4 Direction.......................................11
1.3.5 Size ............................................12
1.3.6 Texture.........................................13
1.3.7 Color........................................... 14
1.4 How Game Engines Work ........................... 17
1.4.1 A Generic Game Engine ........................17
1.4.2 The Main Loop .................................18
1.5 A Scripting Primer .......................................26
1.5.1 Logic...........................................27
1.5.2 Comments .....................................31
1.5.3 Functions ......................................32
1.5.4 Variables .......................................33
1.5.4.1 JavaScript Variables...................36
1.5.5 Operators ......................................42
1.5.5.1 Arithmetic Operators .................42
1.5.5.2 Relational Operators..................42
1.5.6 Conditional Statements ........................45
1.5.7 Arrays..........................................53
1.5.8 Objects.........................................56
1.6 A Game Art Asset Primer ............................... 60
1.6.1 The Power of Two Rule .........................61
1.6.2 Using Other People’s Art Assets................ 66
1.7 Summary................................................ 69
Chapter 2 : Real-World Mechanics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
2.1 Introduction............................................. 71
2.2 Principles of Vectors..................................... 72
2.3 Defining 2D and 3D Space...............................77
2.3.1 Cameras ....................................... 78
2.3.2 Local and World Coordinate Systems........... 85
v
2.3.3 Translation, Rotation, and Scaling................ 85
2.3.4 Polygons and Normals.......................... 90
2.4 Two-Dimensional Games in a 3D Game Engine .......... 93
2.4.1 Quaternions? ................................... 98
2.4.2 Quaternions to the Rescue . . . . . . . . . . . . . . . . . . . . . . 99
2.5 The Laws of Physics ................................... 109
2.5.1 The Law of Gravity............................... 111
2.5.2 The First Law of Motion......................... 113
2.5.3 The Second Law of Motion ...................... 117
2.5.4 The Third Law of Motion........................ 118
2.6 Physics and the Principles of Animation ................ 121
2.6.1 Squash and Stretch ............................ 122
2.6.2 Anticipation ................................... 128
2.6.3 Follow-Through ............................... 129
2.6.4 Secondary Motion.............................. 131
2.7 2D and 3D Tricks for Optimizing Game Space .......... 134
2.7.1 Reducing Polygons ............................ 135
2.7.1.1 Use Only What You Need ............. 135
2.7.1.2 Backface Culling...................... 135
2.7.1.3 Level of Detail ......................... 137
2.7.2 Camera Viewing Volume....................... 139
2.7.3 Fog............................................. 141
2.7.4 Textures ........................................ 141
2.7.4.1 Moving Textures ..................... 142
2.7.4.2 Blob Shadows........................ 143
2.7.5 Billboards ..................................... 144
2.8 Summary ............................................. 146
Chapter 3: Animation Mechanics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
3.1 Introduction............................................147
3.2 Sprites ................................................ 148
3.3 Texture Atlas .......................................... 149
3.4 Animated Sprites...................................... 153
3.5 Baked 3D Animations...................................159
3.6 Biomechanics ......................................... 168
3.7 Animation Management............................... 172
3.7.1 Single 2D Sprite Actions........................ 172
3.7.2 Single-Filed 3D Animations .................... 177
3.8 Secondary Animation ................................. 179
3.9 Summary ............................................. 181
Chapter 4: Game Rules and Mechanics . . . . . . . . . . . . . . . . . . . . . . . . . . . .183
4.1 Introduction .......................................... 183
4.2 Game Mechanics...................................... 184
vi
4.3 Primary Mechanics...................................186
4.3.1 Searching ..................................186
4.3.2 Matching...................................187
4.3.3 Sorting .....................................187
4.3.4 Chancing...................................188
4.3.5 Mixing......................................189
4.3.6 Timing .....................................189
4.3.7 Progressing.................................190
4.3.8 Capturing ..................................190
4.3.9 Conquering.................................190
4.3.10 Avoidance..................................191
4.3.11 Collecting ..................................191
4.4 Developing with Some Simple Game Mechanics . . . . . . 192
4.4.1 Matching and Sorting.......................192
4.4.2 Shooting, Hitting, Bouncing, and Stacking . . . 208
4.4.3 Racing......................................213
4.4.4 Avoidance and Collecting...................217
4.4.5 Searching ..................................223
4.5 Rewards and Penalties ...............................226
4.6 Summary............................................229
Reference...................................................230
Chapter 5: Character Mechanics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .231
5.1 Introduction......................................... 231
5.2 Line of Sight ......................................... 233
5.3 Graph Theory........................................238
5.4 Waypoints........................................... 239
5.4.1 Searching through Waypoints............... 241
5.5 Finite State Machines ................................ 251
5.6 Flocking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265
5.7 Decision Trees ....................................... 271
5.8 Fuzzy Logic.......................................... 276
5.9 Genetic Algorithms ..................................283
5.10 Cellular Automata....................................288
5.11 Summary............................................289
Chapter 6: Player Mechanics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .291
6.1 Introduction......................................... 291
6.2 Game Structure...................................... 292
6.3 Principles of Game Interface Design..................300
6.3.1 User Profiling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300
6.3.2 Metaphor .................................. 301
6.3.3 Feature Exposure........................... 302
6.3.4 Coherence..................................303
6.3.5 State Visualization ..........................304
vii
6.3.6 Shortcuts.....................................304
6.3.7 Layout........................................305
6.3.8 Focus.........................................306
6.3.9 Help..........................................306
6.4 Inventories............................................308
6.5 Teleportation ......................................... 323
6.5.1 Implicit Teleports ............................. 324
6.5.2 Explicit Teleports ............................. 326
6.6 Summary ............................................. 328
Chapter 7: Environmental Mechanics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .329
7.1 Introduction .......................................... 329
7.2 Map Design Fundamentals ............................ 330
7.2.1 Provide a Focal Point.......................... 330
7.2.2 Guide and Restrict the Player’s Movement..... 330
7.2.3 Scaling ....................................... 332
7.2.4 Detail......................................... 332
7.2.5 Map Layout................................... 333
7.2.5.1 Open ............................... 335
7.2.5.2 Linear............................... 335
7.2.5.3 Branching .......................... 336
7.2.5.4 Spoke and Hub ..................... 336
7.2.6 Other Considerations ......................... 337
7.2.6.1 Player Starting Position.............. 337
7.2.6.2 Flow................................ 337
7.2.6.3 Trapping............................ 337
7.2.6.4 Use the 3rd Dimension............... 337
7.2.6.5 Vantage Points...................... 338
7.3 Terrain ................................................ 338
7.3.1 Drawing a Terrain............................. 339
7.3.2 Procedural Terrain ............................344
7.3.3 Procedural Cities..............................349
7.3.4 Infinite Terrain ................................ 355
7.4 Camera Tricks ......................................... 357
7.4.1 Depth of Field ................................ 358
7.4.2 Blur........................................... 358
7.4.3 Grayscale..................................... 359
7.4.4 Motion Blur................................... 359
7.4.5 Sepia Tone.................................... 359
7.4.6 Twirl..........................................360
7.4.7 Bloom........................................360
7.4.8 Flares.........................................360
7.4.9 Color Correction..............................360
7.4.10 Edge Detection............................... 361
7.4.11 Crease........................................ 361
7.4.12 Fish Eye....................................... 361
viii
7.4.13 Sun Shafts.................................... 361
7.4.14 Vignette...................................... 362
7.4.15 Screen Space Ambient Occlusion ............. 362
7.5 Skies..................................................363
7.5.1 Skyboxes.....................................363
7.5.2 Sky Domes ...................................365
7.5.3 Clouds .......................................368
7.6 Weather............................................... 370
7.6.1 Wind . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 370
7.6.2 Precipitation ..................................374
7.7 Particles................................................374
7.8 Summary .............................................382
Reference...................................................382
Chapter 8: Mechanics for External Forces . . . . . . . . . . . . . . . . . . . . . . . . . .383
8.1 Introduction ..........................................383
8.2 Mobile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 384
8.2.1 Design Considerations........................384
8.2.1.1 Text ................................385
8.2.1.2 Icons and User Interface Elements...386
8.2.1.3 Gameplay...........................386
8.2.2 Haptics....................................... 391
8.2.3 Accelerometer................................ 392
8.2.4 Orientation................................... 393
8.2.5 Web Services.................................396
8.2.6 GPS .......................................... 401
8.3 Gestures and Motion................................. 406
8.4 3D Viewing.............................................410
8.4.1 Side-By-Side ................................410
8.4.2 Anaglyphs ..................................413
8.4.3 Head-Mounted Displays .....................414
8.5 Augmented Reality.....................................416
8.6 The Social Mechanic................................... 423
8.6.1 External Application Security Matters ......... 424
8.6.2 Twitter ....................................... 427
8.6.3 Facebook..................................... 432
8.7 Platform Deployment: The App Store, Android
Market, and Consoles.................................. 439
8.7.1 Publishing for the App Store and Android
Market ....................................... 439
8.7.2 Console Publishing ...........................440
8.7.3 Download Direct to Player ....................440
8.8 Summary ............................................. 441
8.9 A Final Word.......................................... 441
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .443
ix