3D game engine programming

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TEAM LinG - Live, Informative, Non-cost and Genuine!

TEAM LinG - Live, Informative, Non-cost and Genuine!

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TEAM LinG - Live, Informative, Non-cost and Genuine!

To my beloved wife Rike and our son Tim

TEAM LinG - Live, Informative, Non-cost and Genuine!

In a world designed by the men in gray who decide how we live in brief, there’s a

master plan for the company men from the cradle to the company grave.

“Return of Alex,” Die Toten Hosen

Writing about the things I like is pretty much one of my favorite hobbies. After

all, it is a good way to pull even more people over to the dark side. This book

is about the dark side of programming 3D engines for video game applica￾tions, and I hope to pull as many of you into the fun side of programming computer

graphics stuff as I can.

It took some time to write the original version of this book as well as complete the English

translation for it. A lot of things happened during that time, but the most important event

was my little son Tim’s arrival into this world. Even if doing 3D graphics is a lot of fun,

Tim taught me that a baby’s smile is way more beautiful than the most perfect 3D scene

with per-pixel lighting, real-time shadows, and glow effects.

Besides my baby Tim, a lot of other people took their share in bringing this book about,

and I would like to thank all of those people. I first want to mention Oli (Oliver Düvel),

who wrote the chapter on character animation and a large portion of the network device

chapter. For the original version of this book, Marcus Beck and Boris Karnikowski looked

after me and helped me get the book done. Working with them was a pleasure, as they

were friendly and motivated me. The same applies for Emi Smith, who organized the

English version of the book and who tolerated my tardiness on due dates with a smile on

her face and in her friendly e-mails. Thanks, Emi. And thanks to André LaMothe for

establishing the contact. vi

Acknowledgments

TEAM LinG - Live, Informative, Non-cost and Genuine!

Marco Kögler was kind enough to help me out with tips and tricks and listened carefully

when I described scene management and lighting ideas to him. He pointed out weak￾nesses in the approaches and helped me with per-pixel lighting topics. Finally, I would like

to thank the band Toten Hosen for the great music that kept me going and Jacobs for the

instant coffee that kept me running.

Last, but not least, thanks to Rike, who makes all this possible.

Stefan Zerbst

Diligence is neither an ability nor a talent. It is a matter of habit.

Peter F. Drucker

These days, it is important to create video games that fascinate the player. To create

this fascination, a video game needs very basic elements, such as network modes

and character animation. The goal of these elements is to increase the level of

interactivity the game is design for.

Personally, I am always astonished by the development of the character animation tech￾niques employed in video games. Starting with plain, animated image files called sprites

in the 80s and ending with the highly precise animations of characters with facial expres￾sions moving through virtual game worlds, animations techniques are developing at

amazing speeds.

I’ve had a lot of fun contributing to this book, and I hope you will have as much fun read￾ing it.

Oliver Düvel

Acknowledgments vii

TEAM LinG - Live, Informative, Non-cost and Genuine!

Stefan Zerbst started programming on the ancient C16 and now holds a German Diplom

degree in Computer Science in Economics. During his studies he founded the German

hobby game development community ZFX (www.zfx.info), which is the biggest and most

active development community in Germany. He has already published two best-selling

books about game programming and also shares his comprehensive experience in this

field by holding lectures about game programming at a German university and the online

academy Gameversity (ww.gameversity.com).

Oliver Düvel works as a project manager in the field of support for a medium-sized soft￾ware company in Germany. He started programming in the early 1980s and did his first

vector and matrix programs using assembler to visualize three-dimensional objects.

About the Authors

viii

TEAM LinG - Live, Informative, Non-cost and Genuine!

André LaMothe, CEO, Xtreme Games LLC, has been involved in the computer industry

for more than 25 years. He wrote his first game for the TRS-80 and has been hooked ever

since! His experience includes 2D/3D graphics, AI research at NASA, compiler design,

robotics, virtual reality, and telecommunications. His books are top sellers in the game

programming genre, and his experience is echoed in the Premier Press Game Development

books.

ix

About the Series Editor

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x

Letter from the Series Editor

Today there are many 3D graphics and game programming books to choose from.

However, the development of a 3D game engine is usually left as an exercise for the

reader because the majority of 3D engine work involves the implementation of the

3D rendering pipeline itself. Unfortunately, many readers still have problems putting

theory into practice and creating a professional quality 3D game engine that can be

used to develop actual production-ready games. Fortunately for us, Stefan Zerbst has

stepped up to the plate and taken the opposite approach for 3D Game Engine Pro￾gramming. Instead of assuming you know nothing about math or 3D graphics, he

assumes that you are familiar with these areas and comfortable with C++ and the

DirectX/3D API. Given this assumption, for the first time really, an entire book is

dedicated to creating the framework for and implementing an entire 3D game

engine, aptly named the “ZFXEngine.” (I will let you learn what it stands for.)

With that in mind, this book targets the intermediate or advanced 2D/3D game pro￾grammer who wants to see in detail the construction of an entire 3D engine ready to

develop commercial games and not just demos. The ZFXEngine is a fully featured

3D engine supporting advanced 3D graphics, shading, model loading, spatial parti￾tioning, networking, audio, scene management, and more. If you can read and

understand everything in this book, not only will you be in a superior position to

develop your own 3D game engine, but you will also have the background to take the

lead position at a studio, defining and developing an engine for them.

And as if that wasn’t enough, the book ends with the implementation of a death￾match shooter to show you just a sample of what the ZFXEngine and the concepts

herein can do. In conclusion, this book will round out even the most wicked 3D

graphics programmer, or give the newbie 3D graphics programmer a roadmap to

where he is going. I highly recommend it!

Sincerely,

André LaMothe

Series Editor, Premier Game Development series

ceo@nurve.net

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xi

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .xxiv

Part I Introduction to the Topics 1

Chapter 1

3D Engines and Game Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

Chapter 2

Designing the Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31

Chapter 3

Engineering the Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41

Chapter 4

Fast 3D Calculus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .91

Part II Rendering Graphics 187

Chapter 5

Materials, Textures, and Transparency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .189

Chapter 6

The Render Device of the Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .235

Chapter 7

3D Pipelines and Shaders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .335

Contents at a Glance

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xii Contents at a Glance

Chapter 8

Loading and Animating 3D Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .387

Part III Support Modules for the Engine 445

Chapter 9

The Input Interface of the Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .447

Chapter 10

The Audio Interface of the Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .483

Chapter 11

The Network Interface of the Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .503

Chapter 12

Timing and Movement in the Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .569

Chapter 13

Scene Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .585

Part IV Black Art of Game Programming 665

Chapter 14

Computer-Aided Design (CAD) Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .667

Chapter 15

Deathmatch Shooter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .787

Epilogue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .843

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .845

TEAM LinG - Live, Informative, Non-cost and Genuine!

xiii

Contents

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .xxiv

Part I Introduction to the Topics 1

Chapter 1 3D Engines and Game Programming . . . . . . . . . . . . . . . . . .3

Buzzword Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

Engines versus APIs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

What Exactly Is an Engine? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

A Kind of Magic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Nostalgia and Modern Times . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

The Problems of Modern Times . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

Wizardry and Art: Creating the Magic . . . . . . . . . . . . . . . . . . . . . .9

The Development Process of a Video Game . . . . . . . . . . . . . . . . . . .10

Professional Perspectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12

Game Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13

Lead Programmer / Technical Director . . . . . . . . . . . . . . . . . . . . . .14

Game Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14

Game Proposal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

Publisher, Publishing, and Revenues . . . . . . . . . . . . . . . . . . . . . . .23

Alternatives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26

Direct3D versus OpenGL Wars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26

Flame Wars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27

Drivers and Hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27

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xiv Contents

What Are We Going to Use? . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27

Why Do It the Hard Way If There Is an Easy Way? . . . . . . . . . . . . . .28

D3DX Helper Library . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28

Knowing Instead of Copying . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29

Get Ready to Rock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29

Chapter 2 Designing the Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31

Requirements for the Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31

Naming the Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31

Is the Game Code Autonomous? . . . . . . . . . . . . . . . . . . . . . . . . . .32

Other Video Game Engine Requirements . . . . . . . . . . . . . . . . . . .33

API Independence through Interface Definitions . . . . . . . . . . . . . . .34

The Structure of the Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35

Interfaces and Dynamic Link Libraries . . . . . . . . . . . . . . . . . . . . . .36

Static Libraries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37

Components of the Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37

ZFXRenderDevice Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37

ZFXInputDevice Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37

ZFXAudioDevice Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38

ZFXNetworkDevice Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38

ZFX3D Library . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38

ZFXGeneral Library . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39

One Look Back, Two Steps Forward . . . . . . . . . . . . . . . . . . . . . . . . . .39

Chapter 3 Engineering the Engine . . . . . . . . . . . . . . . . . . . . . . . . . . .41

What Is an Interface? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41

Abstract Classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42

Virtual Member Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43

Defining the Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43

About DLLs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44

More About the Renderer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45

Workspace for the Implementations . . . . . . . . . . . . . . . . . . . . . . . . .45

Loading DLLs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46

Exporting Classes from DLLs . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46

ZFXRenderer: A Static Library As Manager . . . . . . . . . . . . . . . . . .47

ZFXD3D: A DLL As Render Device . . . . . . . . . . . . . . . . . . . . . . . . .48

ZFXRenderDevice: An Abstract Class As Interface . . . . . . . . . . . . .50

Implementing the Static Library . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52

Loading DLLs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55

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