Unity 4.x Game Development by Example Beginner's Guide

By Ryan Henson Creighton

In Detail

Unity is one of the biggest game engines in the world, providing the user with a range of important tools that they need to bring their ideas into reality. Beginner game developers are optimistic, passionate, and ambitious, but that ambition can be dangerous! Too often, budding indie developers and hobbyists bite off more than they can chew. Games like Angry Birds, Cut the Rope, and Fruit Ninja are fun, simple games that have delighted players and delivered big profits to their creators. This is the perfect climate for new game developers to succeed by creating simple games with Unity, starting today.

This book teaches you the ins and outs of the unique Unity game engine interface. Clear and concise code examples written in both Unity Javascript and C# take you through the step-by-step process of building five small, functional games. With this understanding you can start making your own mark on the game industry!

With absolutely no programming or game development experience, you will learn how to build five simple games in Unity by following step-by-step instructions, peppered with amusing analogies and anecdotes from an experienced indie developer. Following a primer on simplifying your game ideas to that single "something" that keeps players coming back for more, dive into the Unity game engine by creating a simple bat-and-ball game. From there, you'll build a complete memory game using only the Unity GUI system. After building a 2.5D mouse avoider game, you'll learn how to re-skin the project to completely change the game's theme. Incorporating everything you've learned, you'll return to complete the bat-and-ball game by adding scoring, replay flow, sound effects, and animations. Finally, in the new bonus chapter, you'll program some simple AI (Artificial Intelligence) for a tic tac toe game.

"Unity 4.x Game Development by Example" is a fun and light-hearted exploration of one of the most powerful game engines on the market today. Find out what all the fuss is about by getting up to speed using this book!

Approach

This is a practical and light-hearted guide to get to grips with creating your first games, with easy-to-follow, step-by-step tutorials using the award winning Unity engine.

Who this book is for

If you’ve ever wanted to enter the world of independent game development but have no prior knowledge of programming or game development, then this is the book for you. Game developers transitioning from other tools like GameMaker and Flash will find this a useful tool to get them up to speed on the Unity engine, as will anyone who has never handled the Unity engine before.

• Language: English
• Publisher: Packt Publishing
• Release date: Dec 26, 2012
• ISBN: 9781849695275

Ryan Henson Creighton

Ryan Henson Creighton is a veteran game developer, and the founder of Untold Entertainment Inc. (http://www.untoldentertainment.com) where he creatively consults on games and applications. Untold Entertainment creates fantastically fun interactive experiences for players of all ages. Prior to founding Untold, Ryan worked as the Senior Game Developer at Canadian media conglomerate Corus Entertainment, where he created over fifty advergames and original properties for the YTV, Treehouse TV, and W networks. Ryan is the co-creator of Sissy's Magical Ponycorn Adventure, the game he authored with his then five-year-old daughter Cassandra. Ryan is the Vice President of the IGDA Toronto Chapter. He is also the author of the book that you are currently reading. When Ryan is not developing games, he's goofing off with his two little girls and his funloving wife in downtown Toronto.

Book preview

Table of Contents

Unity 4.x Game Development by Example Beginner's Guide

Credits

About the Author

About the Reviewers

www.PacktPub.com

Support files, eBooks, discount offers and more

Why Subscribe?

Free Access for Packt account holders

Preface

A word about the third edition

Your future as a game developer

What this book covers

What you need for this book

Who this book is for

Conventions

Reader feedback

Customer support

Downloading the color images of this book

Downloading the example code

Errata

Piracy

Questions

1. That's One Fancy Hammer!

Introducing Unity 3D

The engine, the tool, and the all-weather tires

Unity takes over the world

Why choose Unity?

Why burn this book and run away screaming?

Browser-based 3D – welcome to the future

Time for action – install the Unity Web Player

Welcome to Unity 3D!

What can I build with Unity?

FusionFall

Completely hammered

Should we try to build FusionFall?

Another option

Off-Road Velociraptor Safari

Fewer features, more promises

Maybe we should build Off-Road Velociraptor Safari?

I bent my Wooglie

Big Fun Racing

Diceworks

Lovers in a Dangerous Spacetime

Showcase Showdown

Unity Technologies – Made with Unity page

Kongregate

The iOS App Store

Walk before you can run (or double jump)

There's no such thing as finished

Stop! Hammer time

Fight Some Angry Bots

The wonders of technology!

The Scene window

The Game window

The Hierarchy panel

The Project panel

The Inspector panel

Heads Up?

Layers and layout dropdowns

Playback controls

Scene controls

Don't stop there – live a little!

Summary

Big ambition, tiny games

2. Let's Start with the Sky

That little lightbulb

The siren song of 3D

Features versus content

A game with no features

Mechanic versus skin

Trapped in your own skin

That singular piece of joy

One percent inspiration

Motherload

Possible additional features:

Heads up!

Artillery Live!

The skinny on multiplayer

Bang for your buck

Pong

The mechanic that launched a thousand games

Have a go hero – redesign your favorite games

Toy or story

Pop Quiz – finding that singular piece of joy

Redefining the sky

Summary

Let's begin

3. Game #1 – Ticker Taker

Kick up a new Unity project

Where did everything go?

'Tis volley

Keep the dream alive

Slash and burn!

The many faces of keep-up

Creating the ball and the hitter

Time for action – create the Ball

What just happened – that's all there is to it?

A ball by any other name

Time for action – rename the Ball

Origin story

XYZ/RGB

Time for action – move the Ball Into the Sky

Time for action – shrink the Ball

Time for action – save your scene

Time for action – add the Paddle

What's a Mesh?

Poly wants to crack your game performance?

Keeping yourself in the dark

Time for action – add a light

Time for action – move and rotate the light

Have a go hero

Extra credit

Are you a luminary?

Who turned out the lights?

Darkness reigns

Cameramania

Time for action – test your game

Let's get physical

Add physics to your game

Understanding the gravity of the situation

More bounce to the ounce

Time for action – make the Ball bouncy

Have a go hero

Summary

Following the script

4. Code Comfort

What is code?

Time for action – write your first Unity Script

A leap of faith

Lick it and stick it

Disappear me!

What just happened?

It's all Greek to me

You'll never go hungry again

With great sandwich comes great responsibility

Examining the code

Time for action – find the Mesh Renderer component

Time for action – make the ball re-appear

Ding!

Time for action – journey to the Unity Script Reference

The Renderer class

Have a go hero – pulling the wings off of flies

What's another word for huh?

It's been fun

Time for action – unstick the Script

Gone, but not forgotten

Why code?

Equip your baby bird

Time for action – create a new MouseFollow Script

What just happened?

A capital idea

Animating with code

Time for action – animate the Paddle

What just happened – what witchcraft is this?

Why didn't the Paddle animate before?

Pick a word – (almost) any word

Screen coordinates versus World coordinates

Move the Paddle

Worst. Game. Ever.

See the matrix

Time for action – listen to the paddle

A tiny bit o' math

Tracking the numbers

Futzing with the numbers

Time for action – Log the New Number

She's a-work!

Somebody get me a bucket

Time for action – declare a variable to store the Screen midpoint

What just happened – we've gone too var

Using all three dees

Time for action – follow the y position of the mouse

A keep-up game for robots

Once more into the breach

Time for action – re-visit the Unity Language Reference

Our work here is done

Time for action – add the sample code to your Script

One final tweak

What's a quaternion?

Wait, what's a quaternion?

WHAT THE HECK IS A QUATERNION??

Educated guesses

More on Slerp

Right on target

Have a go hero – time to break stuff

Keep it up

Beyond the game mechanic

C# Addendum

5. Game #2 – Robot Repair

You'll totally flip

A blank slate

You're making a scene

Time for action – set up two scenes

No right answer

Time for action – prepare the GUI

The beat of your own drum

Time for action – create and link a custom GUI skin

What just happened?

Time for action – create a button UI control

What just happened?

Have a go hero – no sense sitting around on your button

Want font?

Cover your assets

Time for action – nix the mip-mapping

Front and center

Time for action – center the button

What just happened – investigating the code

The waiting game

The easiest button to button

To the game!

Time for action – add both scenes to Build List

Set the stage for robots

Time for action – prepare the game scene

The game plan

Have some class!

Time for action – store the essentials

A matter of great import

Building a better bucket

How big is your locker?

Start me up

Going loopy

The anatomy of a loop

To nest is best

Seeing is believing

Time for action – create an area to store the grid

Have a go hero – don't take my word for it!

Build that grid

What just happened – grokking the code

Now you're playing with power!

C# addendum

6. Game #2 – Robot Repair Part 2

From zero to game in one chapter

Finding your center

Time for action – centering the game grid vertically

What just happened?

Time for action – centering the game grid horizontally

What just happened – coding like a ninja

Down to the nitty griddy

Do the random card shuffle

Time for action – preparing to build the deck

Let's break some robots

Time for action – building the deck

What just happened – dissecting the bits

Time for action – modifying the img argument

What just happened?

What exactly is this?

Have a go hero – grokketh-thou Random.Range()?

Random reigns supreme

Second dragon down

Time to totally flip

Time for action – making the cards two-sided

Time for action – building the card-flipping function

Time for action – building the card-flipping function

What just happened – dissecting the flip

Pumpkin eater

What just happened?

Stabby McDragonpoker rides again

Game and match

Time for action – ID the cards

What just happened?

Time for action – comparing the IDs

What just happened?

On to the final boss

Endgame

Time for action – checking for victory

What just happened?

Have a go hero – extra credit

Endgame

Bring. It. On.

C# Addendum

7. Don't Be a Clock Blocker

Apply pressure

Time for action – preparing the Clock Script

Time for more action – preparing the clock text

Still time for action – changing the clock text color

Time for action rides again – creating Font Texture and Material

Time for action – what's with the tiny font?

What just happened – was that seriously magic?

Time for action – preparing the clock code

What just happened – that's a whole lotta nothing

Time for action – creating the countdown logic

Time for action – displaying the time on-screen

What just happened – what about that terrifying code?

Picture it

Time for action – grabbing the picture clock graphics

What just happened – you can do that?

Time for action – Flex those GUI muscles

What just happened – how does it work?

The incredible shrinking clock

Keep your fork – there's pie!

Pop quiz – how do we build it?

How they did it

Time for action – rigging up the textures

Time for action – writing the pie chart script

What just happened?

Time for action – commencing operation pie clock

What just happened – explaining away the loose ends

Time for action – positioning and scaling the clock

Have a go hero – rock out with your clock out

Unfinished business

C# Addendum

8. Hearty Har Har

Welcome to Snoozeville

Model behavior

Time for action – exploring the models

Time for action – hands up!

What just happened – size matters

Time for action – changing the FBX import scale settings

Time for action – making the mesh colliders convex

Time for action – making the hands and tray follow the mouse

What just happened – monkey see, monkey do

Time for action – getting your heart on

Time for action – ditching the Ball and Paddle

What just happened – bypass the aorta

Time for action – material witness

What just happened – understanding Materials

Have a go hero – adding materials to the other models

This just in – this game blows

Time for action – multiple erections

Time for action – creating a font texture

Time for action – create the HeartBounce script

What just happened – charting a collision course

Time for action – tagging the tray

Time for action – tweaking the bounce

What just happened – storing velocity

Time for action – keeping track of the bounces

Time for action – adding the lose condition

What just happened – understanding the code

Time for action – adding the Play Again button

What just happened?

Ticker taken

C# Addendum

9. Game #3 – The Break-Up

Time for action – bombs away!

Time for action – poke those particles

Time for action – creating a spark material

Have a go hero – time to ignite your creative spark

Time for action – prefabulous

What just happened – what's a Prefab?

Time for action – lights, camera, and apartment

Time for action – adding the character

Time for action – registering the animations

Time for action – scripting the character

What just happened – stepping through the step code

Time for action – open the pod bay door, Hal

Time for action – collision-enable the character

Time for action – apocalypse now?

Time for action – go boom

Time for action – kill kill murder die

Time for action – the point of impact

Time for action – hook up the explosion

Summary

C# addendum

10. Game #3 – The Break-Up Part 2

Time for action – amass some glass

Time for action – create a particle system

What just happened – getting smashed

Time for action – make it edgier!

What just happened – I fall to pieces

Time for action – contain the explosion

What just happened – duped?

Time for action – let's get lazy

What just happened – FallingObject: The PuppetMaster

Very variable?

Terminal velocity is a myth – bombs fall faster

What just happened – when game objects collide?

Time for action – tag the objects

Time for action – write the collision detection code

Time for action – animation interrupts

What just happened – the impenetrable stare

Time for action – add facial explosions

What just happened – raindrops keep 'sploding on my head

Time for action – make some noise

Time for action – add sounds to FallingObject

Silent 'Splosion

What's the catch?

Have a go hero – sound off

Time for action – mix it up a bit

Have a go hero – filling in the gaps

Summary

C# Addendum

11. Game #4 – Shoot the Moon

Time for action – duplicate your game project

Time for action – space the shooter up a bit

Time for action – enter the hero

Time for action – it's a hit!

Time for action – bring on the bad guys

Time for action – do some housekeeping

Time for action – fixing the fall

Time for action – tweak the hero

What just happened – hooray for lazy!

Time for action – give up the func

Time for action – itchy trigger finger

Time for action – futurize the bullet

Time for action – building Halo

Time for action – fire!

Time for action – code do-si-do

What just happened – eat lead

Time for action – the maaagic of aaaarguments

Time for action – add the most important part of any space shooter

Last year's model

Have a go hero – filling in the empty space

Summary

C# Addendum

12. Game #5 – Kisses 'n' Hugs

Computers that think

Time for action – haul in the hallway

Time for action – hash it out

One Script to rule them all

Time for action – it's hip to be square

What just happened – find and click

Squaring the Square

Time for action – now you see it...

Family values

Time for action – X marks the spot

Time for action – boy O boy

Time for action – bottoming out

Here comes the drop

What just happened – to collide or not to collide?

Time for action – +9 accuracy

Time for action – solve for X

What just happened – lockdown

Time for action – it takes two to Tic Tac Toe

What just happened – alternating between players

Time for action – designer to player. Come in, player.

What just happened – prompt service

Slowly building to a climax

Have a go hero – think it through

Read after thinking

What just happened – building a more complex lock

On deaf ears

Time for action – pretty maids all in a row

What just happened – order!

Winner is coming

Codesplosion

Need-to-know basis

Need-to-know basis

Clean-up on aisle code

What just happened – vending machine

Shave and a haircut

What just happened – hunting for a win

Time for action – check for a win

Sore loser

Time for action – notify the winner

Time for action – you win. Now what?

Have a go hero – draw, pardner

Nice moves

Time for action – the final bug

All done but for the shouting

C# addendum

13. AI Programming and World Domination

Take it away, computer

Time for action – add computer control

Herpa derp derp

What just happened – making a list, checking it twice

Unpacking the code

Time for action – code consolidation

Tic Tac Toe at the speed of light

Sore loser

Click-spamming for fun and profit

Artificial stupidity

Have a go hero – solve Tic Tac Toe

Time for action – winning is everything

It's a trap!

The leftovers

Time for action – pseu pseu pseudocode

What just happened – stepping through the strategy

Time for action – begin at the end

Time for action – the final four

Code one, get one free

Have a go hero - stump the author

The actual intelligence behind artificial intelligence

Time for action – score!

What just happened – the search is on

Shut your trap

Detecting the tri-corner trap

Time for action – to catch a competitor

What just happened – I'm running out of trap puns

Perfection Horrible, horrible perfection.

Time for action – programming fallibility

What just happened – roll for initiative

Turning it up to Smart

Code encore

Summary

More hospitality

C# addendum

14. Action!

Open heart surgery

Time for action – haul in the hallway

Time for action – meet me at camera two

Time for action – adjust Main Camera

Time for action – deck the halls

Time for action – turn on the lights

Time for action – set up the camera rig

Time for action – animate the bouncer

What just happened – red and raging

Time for action – I like to move it move it

Have a go hero – bounce your brains out

Time for action – animate the runner

What just happened – holy hospital rampage, Batman!

Time for action – how to handle Nurse Slipperfoot

Time for action – you spin me right round

Have a go hero – give Robo-Nurse a soul

Have a go hero – use your new-found powers for good

Time for action – deploy your game

Time to grow

Beyond the book

A. Appendix

Online resources

Offline resources

Free development tools

Graphics

Sound

The Unity Asset Store

Game portals

Index

Unity 4.x Game Development by Example Beginner's Guide

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Unity 4.x Game Development by Example Beginner's Guide

Copyright © 2013 Packt Publishing

All rights reserved. No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, without the prior written permission of the publisher, except in the case of brief quotations embedded in critical articles or reviews.

Every effort has been made in the preparation of this book to ensure the accuracy of the information presented. However, the information contained in this book is sold without warranty, either express or implied. Neither the author, nor Packt Publishing, and its dealers and distributors will be held liable for any damages caused or alleged to be caused directly or indirectly by this book.

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First published: September 2010

Second edition: September 2011

Third edition: December 2013

Production Reference: 1191213

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Cover Image by Dan John Cox (<http://danjohncox.tumblr.com/>)

Credits

Author

Ryan Henson Creighton

Reviewers

Trond Abusdal

Huzaifa Arab

John Hutchinson

Wei Wang

Acquisition Editors

Wilson D'souza

Mary Jasmine Nadar

Owen Roberts

Lead Technical Editors

Owen Roberts

Poonam Jain

Technical Editors

Tanvi Bhatt

Akashdeep Kundu

Edwin Moses

Nikhil Potdukhe

Tarunveer Shetty

Faisal Siddiqui

Sonali Vernekar

Project Coordinator

Venitha Cutinho

Proofreaders

Elinor Perry-Smith

Mario Cecere

Bridget Braund

Indexers

Mariammal Chettiyar

Mehreen Deshmukh

Rekha Nair

Tejal Soni

Graphics

Sheetal Aute

Production Coordinator

Nitesh Thakur

Cover Work

Nitesh Thakur

About the Author

Ryan Henson Creighton is a veteran game developer, and the founder of Untold Entertainment Inc. (http://www.untoldentertainment.com) where he creatively consults on games and applications. Untold Entertainment creates fantastically fun interactive experiences for players of all ages. Prior to founding Untold, Ryan worked as the Senior Game Developer at Canadian media conglomerate Corus Entertainment, where he created over fifty advergames and original properties for the YTV, Treehouse TV, and W networks. Ryan is the co-creator of Sissy's Magical Ponycorn Adventure, the game he authored with his then five-year-old daughter Cassandra. Ryan is the Vice President of the IGDA Toronto Chapter. He is also the author of the book that you are currently reading.

When Ryan is not developing games, he's goofing off with his two little girls and his fun-loving wife in downtown Toronto.

Big thanks to Cheryl, Cassandra, and Isabel for their love, their support, and their cinnamon rolls. Thanks to Jean-Guy Niquet for introducing me to Unity; to Jim McMajorSupporter McGinley for help with the book outline and ongoing mentorship; to the technical reviewers and Packt Publishing staff for letting me leave a few jokes in the book; and to David Barnes, for having such a great sense of humor in the first place. Special thanks to Michael Garforth and friends from the #unity3d IRC channel on Freenode. I also want to thank Mom, God, and all the usual suspects.

About the Reviewers

Trond Abusdal, though having been interested in computers since his parents bought him and his brother a C64 in the early 90s, he first got into programming years later when writing a modification for Quake2 with a childhood friend.

This interest lead to a bachelor's degree in Computer Science in 2006, after which he started working for TerraVision, a company using game technologies as a tool for education and visualization. In 2008, he first got introduced to Unity, which is still his main game development tool, although knowledge of other technologies and tools often come in handy.

Since 2010, he is a programmer and more recently a partner at Rock Pocket Games, which makes games for a variety of different platforms, both client projects and internal projects.

Huzaifa Arab is a Game Designer by choice and a Game Programmer by need. He has been playing games since young age, which progressed to Modding/Map-making/Scripting, when he realized that some games could be a whole lot more fun if he could put his own twist in them. And so, his hobby became a professional career choice after formally graduating from DSK Supinfogame, India (where his team won the prestigious Square Enix Game Dev Competition). After a year of freelance Game Development, he currently works at Tiny Mogul Games, India, as a Principal Game Designer.

He loves to connect with people interested in Human Computer Interface, Game Engines/VR Tech, Game Design in Education, and Instrumental music. You can drop him a line at <[e-mail]>.

I would like to thank Packt Publishing for giving me an opportunity to review a book on Unity 3D, a technology I am so passionate about. I would like to thank my best friend Angad for recommending me to Packt Publishing and I would like to thank my family and co-workers/friends for their support as I took time out to review such a wonderful book.

John Hutchinson is the founder of Rubber Ducky Games, an independent game development studio based in California.

In addition to being an exceptional programmer in multiple languages and frameworks, he is an experienced graphic designer, talented game system architect and gets excited about experience-focused design (and rubber duckies).

He is especially interested in games which push the boundaries of twitch-reflex response, explore human emotion, or leverage the interactive medium for more powerful learning experiences.

He is currently working with Making Friends Inc. as Lead Engineer and as part of the core design team, to deliver a game intent on teaching kids on the Autism-Asperger's spectrum valuable social skills.

When his face isn't glued to a computer screen he likes to play with his kids, explore board game design, and read technical books like this one.

Thanks to my brothers, for providing feedback (and teaching me some things about games). To my sister, for making me feel like a hero (not a robot). To my parents, for teaching me to be caring and to work my butt off. And to my kids, for just being you. I love you all more than words can express.

Wei Wang made his first iOS casual game with Unity 3D in his college time, which got big success with more than 5 million downloads world-wide. Since then, he has discovered it's a great thing to make great games. After earning his master's degree from Tsinghua University (one of the best universities in China), he joined a game company in Japan and now he is trying to create interesting games with Unity 3D.

Right now, he is a skilled engineer and always eager to learn more. He now lives in Kawasaki with his wife. You can know more about him from his project's page http://project.onevcat.com or find him on his blog http://onevcat.com (Chinese). You can also follow him on twitter @onevcat.

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Preface

A word about the third edition

As I sit here in my luxurious velvet smoking jacket, taking a long draw on a pipe, and admiring the various stuffed hunting trophies around the room in an attitude of quiet contemplation, it dawns on me that I don't smoke or advocate sport-hunting, and that I have no idea what I'm doing in this room. The jacket, however, is quite nice. I think I'll keep it.

It's wonderful to see that this book, one of the very first instructional guides about Unity 3D on the market, has withstood both the test of time, and Unity Technologies' relentless release schedule. Owing to the rapid pace of technology, many things have changed in a few short years. C# has largely overtaken UnityScript as a preferred language; to that end, all of the code in the book has been supplemented with a C# translation, including notes on how to perform that translation yourself for past and future projects.

In the time since the first edition, computers have increasingly become our evil, dominating overlords. With that in mind, the third edition includes two bonus chapters that teach you how to build a two-player game, and then how to program the computer to act as the merciless second player who never loses. That chapter also contains information on how to make the computer player lose, which I present as secret codified data to be used by the resistance movement during the inevitable machine uprising. Stay ever vigilant!

Your future as a game developer

Game Developer has rapidly replaced firetruck as the number one thing that kids want to be when they grow up. Gone are the days when aspiring developers needed a university education, a stack of punch cards, and a room-sized computer to program a simple game. With digital distribution and the availability of inexpensive (or free) game development tools like Unity 3D, the democratization of game development is well underway.

But just as becoming a firetruck is fraught with peril, so too is game development. Too often, aspiring developers underestimate the sheer enormity of the multidisciplinary task ahead of them. They bite off far more than they can chew, and eventually drift away from their game development dreams to become lawyers or dental hygienists. It's tragic. This book bridges the gap between I wanna make games! and I just made a bunch of games! by focusing on small, simple projects that you can complete before you reach the bottom of a bag of corn chips.

What this book covers

Chapter 1, That's One Fancy Hammer!, introduces you to Unity 3D—an amazing game engine and game authoring tool that enables you to create games and deploy them to a number of different devices. You'll play a number of browser-based Unity 3D games to get a sense of what the engine can handle, from a massively-multiplayer online game all the way down to a simple kart racer. You'll download and install your own copy of Unity 3D, and mess around with one of the demos that ships with the product.

Chapter 2, Let's Start with the Sky, explores the difference between a game's skin and its mechanic. Using examples from video game history, including Worms, Mario Tennis, and Scorched Earth, we'll uncover the small, singular piece of joy upon which more complicated and impressive games are based. By concentrating on the building blocks of video games, we'll learn how to distil an unwieldy behemoth of a game concept down to a manageable starter project.

Chapter 3, Game #1 – Ticker Taker, puts you in the pilot seat of your first Unity 3D game project. We'll explore the Unity environment and learn how to create and place primitives, add Components like Physic Materials and rigidbodies, and make a ball bounce on a paddle using Unity's built-in physics engine without ever breaking a sweat.

Chapter 4, Code Comfort, continues the keep-up game project by gently introducing scripting. Just by writing a few simple, thoroughly-explained lines of code, you can make the paddle follow the mouse around the screen to add some interactivity to the game. This chapter includes a crash course in game scripting that will renew your excitement for programming where high school computer classes may have failed you.

Chapter 5, Game #2 – Robot Repair, introduces an often-overlooked aspect of game development—front-of-house User Interface design—the buttons, logos, screens, dials, bars, and sliders that sit in front of your game—is a complete discipline unto itself. Unity 3D includes a very meaty Graphical User Interface system that allows you to create controls and fiddly bits to usher your players through your game. We'll explore this system, and start building a complete two-dimensional game with it! By the end of this chapter, you'll be halfway to completing Robot Repair, a colorful matching game with a twist.

Chapter 6, Game #2 – Robot Repair Part 2, picks up where the last chapter left off. We'll add interactivity to our GUI-based game, and add important tools to our game development tool belt, including drawing random numbers and limiting player control. When you're finished with this chapter, you'll have a completely playable game using only the Unity GUI system, and you'll have enough initial knowledge to explore the system yourself to create new control schemes for your games.

Chapter 7, Don't Be a Clock Blocker, is a standalone chapter that shows you how to build three different game clocks—a number-based clock, a depleting bar clock, and a cool pie wedge clock, all of which use the same underlying code. You can then add one of these clocks to any of the game projects in this book, or reuse the code in a game of your own.

Chapter 8, Hearty Har Har, revisits the keep-up game from earlier chapters and replaces the simple primitives with 3D models. You'll learn how to create materials and apply them to models that you import from external art packages. You'll also learn how to detect collisions between game objects, and how to print score results to the screen. By the end of this chapter, you'll be well on your way to building Ticker Taker—a game where you bounce a still-beating human heart on a hospital dinner tray in a mad dash for the transplant ward!

Chapter 9, Game #3 – The Break-Up, is a wild ride through Unity's built-in particle system that enables you to create effects like smoke, fire, water, explosions, and magic. We'll learn how to add sparks and explosions to a 3D bomb model, and how to use scripting to play and stop animations on a 3D character. You'll need to know this stuff to complete The Break-Up—a catch game that has your character grabbing falling beer steins and dodging explosives tossed out the window by his jilted girlfriend.

Chapter 10, Game #3 – The Break-Up Part 2, completes The Break-Up game from the previous chapter. You'll learn how to reuse scripts on multiple different game objects, and how to build Prefabs, which enable you to modify a whole army of objects with a single click. You'll also learn to add sound effects to your games for a much more engaging experience.

Chapter 11, Game #4 – Shoot the Moon, fulfills the promise of Chapter 2, Let's Start with the Sky, by taking you through a re-skin exercise on The Break-Up. By swapping out a few models, changing the background, and adding a shooting mechanic, you'll turn a game about catching beer steins on terra firma into an action-packed space shooter! In this chapter, you'll learn how to set up a two-camera composite shot, how to use code to animate game objects, and how to re-jig your code to save time and effort.

Chapter 12, Game #5 – Kisses 'n' Hugs, teaches you to build a two-player 3D Tic Tac Toe game entirely within the Unity 3D game authoring tool. You'll learn about writing return values for your custom functions, and using 3D objects to build an essentially 2D game. This simple strategy game forms the basis for the following chapter.

Chapter 13, AI Programming and World Domination, steps you through the process of developing an artificial intelligence program, enabling your computer to win at Tic Tac Toe. From there, you'll modify the terrifyingly perfect AI algorithm so that it randomly makes mistakes, and gives humankind a slim chance at Tic Tac Toe survival.

Chapter 14, Action!, takes you triumphantly back to Ticker Taker for the coup de grace—a bouncing camera rig built with Unity's built-in animation system that flies through a model of a hospital interior. By using the two-camera composite from The Break-Up, you'll create the illusion that the player is actually running through the hospital bouncing a heart on a tin tray. The chapter ends with a refresher on bundling your project and deploying it to the Web so that your millions of adoring fans (including your grandma) can finally experience your masterpiece.

Appendix is an essentially vestigial component of the colon, which can be surgically removed if it gives you any trouble.

What you need for this book

You'll need to be in possession of a sturdy hat, a desk chair equipped with a seatbelt, and an array of delicious snack foods that won't get these pages all cheesy (if you're reading the e-book version, you're all set). Early chapters walk you through downloading and installing Unity 3D (http://unity3d.com/unity/download/). A list of resources and links to additional software can be found in the Appendix.

Who this book is for

If you've ever wanted to develop games, but have never felt smart enough to deal with complex programming, this book is for you. It's also a great kick start for developers coming from other tools like Flash, Unreal Engine, and Game Maker Pro.

Conventions

In this book, you will find a number of styles of text that distinguish between different kinds of information. Here are some examples of these styles, and an explanation of their meaning.

Code words in text are shown as follows: The audio.PlayOneShot command is perfect for collision sound effects.

A block of code is set as follows:

for(var i:int=0; i

{

  var aRobotParts:List. = new List.();

 

  aRobotParts.Add(Head);

  aRobotParts.Add(Arm);

  aRobotParts.Add(Leg);

}

When we wish to draw indicate that a line of code needs to be added or edited, the relevant lines or items are set in bold:

function Awake() {   startTime = Time.time + 5.0; }

New terms and important words are shown in bold. Words that you see on the screen, in menus or dialog boxes for example, appear in the text like this: When you click on the Apply button, Unity creates its set of raster images based on the font that you're importing.

Note

Warnings or important notes appear in a box like this.

Tip

Tips and tricks appear like this.

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Customer support

Now that you are the proud owner of a Packt book, we have a number of things to help you to get the most from your purchase.

Downloading the color images of this book

We also provide you a PDF file that has color images of the screenshots/diagrams used in this book. The color images will help you better understand the changes in the output. You can download this file from https://www.packtpub.com/sites/default/files/downloads/5268OT_ColoredImages.pdf

Downloading the example code

You can download the example code files for all Packt books you have purchased from your account at http://www.packtpub.com. If you purchased this book elsewhere, you can visit http://www.packtpub.com/support and register to have the files e-mailed directly to you. Each project in the book is intended to be built from the ground up, beginning with an new project file. The downloadable .unitypackage files for this book contain the assets (sounds, images, and models) you need to build the projects. You may also download completed, working versions of each project for your reference, though these are not intended to be your first stop – they're more like the answer sheet at the back of a text book.

Errata

Although we have taken every care to ensure the accuracy of our content, mistakes do happen. If you find a mistake in one of our books—maybe a mistake in the text or the code—we would be grateful if you would report this to us. By doing so, you can save other readers from frustration and help us improve subsequent versions of this book. If you find any errata, please report them by visiting http://www.packtpub.com/support, selecting your book, clicking on the errata submission form link, and entering the details of your errata. Once your errata are verified, your submission will be accepted and the errata will be uploaded to our website, or added to any list of existing errata, under the Errata section of that