Unity in Action, Second Edition is a book about programming games in Unity. Think of it as an intro to Unity for experienced programmers. The goal of this book is straightforward: to take people who have some programming experience but no experience with Unity and teach them how to develop a game using Unity.

The best way of teaching development is through example projects, with students learning by doing, and that’s the approach this book takes. I’ll present topics as steps toward building sample games, and you’ll be encouraged to build these games in Unity while exploring the book. We’ll go through a selection of different projects every few chapters, rather than one monolithic project developed over the entire book. (Sometimes other books take the “one monolithic project” approach, but that can make it hard to jump into the middle if the early chapters aren’t relevant to you.)

This book will have more rigorous programming content than most Unity books (especially beginners’ books). Unity is often portrayed as a list of features with no programming required, which is a misleading view that won’t teach people what they need to know in order to produce commercial titles. If you don’t already know how to program a computer, I suggest going to a resource like Codecademy first (the computer programming lessons at Khan Academy work well, too) and then come back to this book after learning how to program.

Don’t worry about the exact programming language; C# is used throughout this book, but skills from other languages will transfer quite well. Although the first part of the book will take its time introducing new concepts and will carefully and deliberately step you through developing your first game in Unity, the remaining chapters will move a lot faster in order to take readers through projects in multiple game genres. The book will end with a chapter describing deployment to various platforms like the web and mobile, but the main thrust of the book won’t make any reference to the ultimate deployment target because Unity is wonderfully platform-agnostic.

As for other aspects of game development, extensive coverage of art disciplines would water down how much the book can cover and would be largely about software external to Unity (for example, the animation software used). Discussion of art tasks will be limited to aspects specific to Unity or that all game developers should know. (Note, though, that there is an appendix about modeling custom objects.)

Roadmap

Chapter 1 introduces you to Unity, the cross-platform game development environment. You’ll learn about the fundamental component system underlying everything in Unity, as well as how to write and execute basic scripts.

Chapter 2 progresses to writing a demo of movement in 3D, covering topics like mouse and keyboard input. Defining and manipulating both 3D positions and rotations are thoroughly explained.

Chapter 3 turns the movement demo into a first-person shooter, teaching you raycasting and basic AI. Raycasting (shooting a line into the scene and seeing what it intersects) is a useful operation for all sorts of games.

Chapter 4 covers art asset importing and creation. This is the one chapter of the book that does not focus on code, because every project needs (basic) models and textures.

Chapter 5 teaches you how to create a 2D puzzle game in Unity. Although Unity started exclusively for 3D graphics, there’s now excellent support for 2D graphics.

Chapter 6 expands the 2D game explanations with platform game mechanics. In particular, we’ll implement controls, physics, and animation for the player.

Chapter 7 introduces you to the latest GUI functionality in Unity. Every game needs a UI, and the latest versions of Unity feature an improved system for creating UIs.

Chapter 8 shows how to create another movement demo in 3D, only seen from third-person perspective this time. Implementing third-person controls will demonstrate a number of key 3D math operations, and you’ll learn how to work with an animated character.

Chapter 9 goes over how to implement interactive devices and items within your game. The player will have a number of ways of operating these devices, including touching them directly, touching triggers within the game, or pressing a button on the controller.

Chapter 10 covers how to communicate with the internet. You’ll learn how to send and receive data using standard internet technologies, like HTTP requests to get XML data from a server.

Chapter 11 teaches how to program audio functionality. Unity has great support for both short sound effects and long music tracks; both sorts of audio are crucial for almost all video games.

Chapter 12 walks you through bringing together pieces from different chapters into a single game. In addition, you’ll learn how to program point-and-click controls and how to save the player’s game.

Chapter 13 goes over building the final app, with deployment to multiple platforms like desktop, web, mobile, and even VR. Unity is wonderfully platform-agnostic, enabling you to create games for every major gaming platform!

There are also four appendixes with additional information about scene navigation, external tools, Blender, and learning resources.

Code conventions, requirements, and downloads

All the source code in the book, whether in code listings or snippets, is in a fixed-width font like this, which sets it off from the surrounding text. In most listings, the code is annotated to point out key concepts, and numbered bullets are sometimes used in the text to provide additional information about the code. The code is formatted so that it fits within the available page space in the book by adding line breaks and using indentation carefully.

The only software required is Unity; this book uses Unity 2017.1, which is the latest version as I write this. Certain chapters do occasionally discuss other pieces of software, but those are treated as optional extras and not core to what you’re learning.

The code listings sprinkled throughout the book generally show what to add or change in existing code files; unless it’s the first appearance of a given code file, don’t replace the entire file with subsequent listings. Although you can download complete working sample projects to refer to, you’ll learn best by typing out the code listings and only looking at the working samples for reference. Those downloads are available from the publisher’s website (www.manning.com/books/unity-in-action-second-edition) and on GitHub (https://github.com/jhocking/uia-2e).

Book forum

Purchase of Unity in Action, Second Edition includes free access to a private web forum run by Manning Publications where you can make comments about the book, ask technical questions, and receive help from the author and from other users. To access the forum, go to https://forums.manning.com/forums/unity-in-action-second-edition. You can also learn more about Manning's forums and the rules of conduct at https://forums.manning.com/forums/about.

Manning’s commitment to our readers is to provide a venue where a meaningful dialogue between individual readers and between readers and the author can take place. It is not a commitment to any specific amount of participation on the part of the author, whose contribution to the forum remains voluntary (and unpaid). We suggest you try asking the author some challenging questions lest his interest stray! The forum and the archives of previous discussions will be accessible from the publisher’s website as long as the book is in print.