Unity is a 3D game authoring tool for Mac and PC. Game engines are the nuts and bolts that sit behind the scenes of every video game. From the artwork right down to the mathematics that decide every frame on screen, the "engine" makes the decisions. Starting out with rendering — the method of displaying graphics on screen, and integrating a control method and a set of rules for the game to follow — the engine is what a developer builds to "house" the game. Modern 3D game engines are a deluge of meticulously written code, and as such, once used for their intended purpose (which is the production of a game they are made for), these engines are often sold, modified, and reused. An obvious example of this is the Epic Games Unreal Engine. Originally developed in the late 90s for Unreal — a PC First Person Shooter the engine has gone on to see massive success in its more recent incarnations, being licensed by other developers for literally hundreds of commercial games and simulations.
Due to the level of complexity and cost of such commercial game engines, the game development industry is a difficult area of interest for potential fresh talent to break into, without studying programming languages such as C++ extensively. Modern console and computer games are built around C++ as it is currently the most efficient language in terms of computational speed, and as such, the structure and commands of commercial games engines require thousands upon thousands of such lines of code to function. This code is delivered in Unity with the help of just-in-time compilation (known as JIT), using the open source C++ library Mono. By using JIT compilation, engines such as Unity can take advantage of high-speed compilation, whereby the code you will write for Unity is compiled to Mono just before it is executed. This is crucial for games that must execute code at specific moments during runtime. In addition to the Mono library, Unity also takes advantage of other software libraries in its functionality, such as Nvidia's PhysX physics engine, OpenGL, and DirectX for 3D rendering and OpenAL for audio. All these libraries are built into the application, so you will not need to worry about learning how to use them individually. So, simply sit back and enjoy them working for you seamlessly within Unity.
The developers of engines also build tools with which to command the functional coding they have created. For example, the creation of an outdoor terrain is held in a set of instructions which define its shape (or topography), visual appearance, and even how it responds to deformation in game. But this set of instructions would be inefficient as a part of the game engine were it not attached to a visual tool to control the aforementioned properties. This is where a Graphical User Interface (GUI) comes in. Game engine developers will often build an interface of tools to aid their team in manipulating parts of the engine in order to save time in the development process and make the engine accessible to potential buyers, post production. This is also true of Unity, as it has a very strong community of users that share their tools in the form of plugins for the package. Visit the Unify community wiki at http://www.unifycommunity.com/wiki for more information.
For many new potential developers, the steep learning curve required to pick up programming languages such as C++, or the engines that utilize it, is simply too great a task to attempt. Without completing degree-level studies in programming or computer animation, it is difficult for many enthusiasts to get started in learning the concepts, methods, and design principles involved in game production. Unity Technologies is one such company that has set out to rectify this. Starting with their own game engine in 2001, the Danish-based game development company endeavoured to strip down their complex game development tools and make a simple, user-driven package that anyone could pick up and begin experimenting with. The team resolved to keep the source code that drives the engine behind the scenes, instead providing a complete GUI (Graphical User Interface) that allows the user to control the powerful engine source code without ever having to create parts of it themselves. This factor has made Unity highly popular with new developers, and is likely one of the key reasons you're reading this book. By establishing logical concepts and categorizing common methods involved in game production, Unity puts the power of its engine into the user's hands, allowing maximum results with minimal effort, thereby encouraging experimentation with the most crucial factor of all — gameplay.
Having appealed to many games developers, Unity has filled a gap in the games development market that few others can fully claim to cater to. Having the ability to produce professional standard games, publish 3D to both Mac and PC, as well as having its own Web Player, Unity is one of the fastest growing game engines in its sector. The engine also has its own Nintendo Wii and Apple iPhone developing versions, meaning that once you have mastered the basics, a pipeline to not only home computer, but also to console and mobile development lies ahead of you.
The fast pace of the entertainment and marketing industries requires a quick turnaround of gaming media. Also, many companies are now looking to packages such as Unity to enable their creatives to produce better products with the greatest of ease. With 2009 seeing the release of Unity version 2.5, and its first steps onto PC format, its usage looks set to skyrocket. But what is Unity? How does it work? What can it do? And most importantly, how can it get you get started on the path to 3D game development in just a few weeks?
This book is designed to cover a set of easy-to-follow examples, which culminate in the production of a First-Person-viewed 3D game, complete with an interactive island environment. By introducing common concepts of game and 3D production, we'll explore the use of Unity to make a player character interact with the game world, and build puzzles for the player to solve in order to complete the game.
Here's a quick chapter-by-chapter overview of what will be covered:
This chapter covers the key concepts we'll need to understand and complete the exercise in this book. It takes a brief look at 3D concepts and the processes used by Unity to create games.
Our game world is but an empty void! We'll kick off with this chapter by taking a look at the various ways to incorporate terrains, externally produced 3D models, and other Unity engine features such as sound and lighting to get your game environment up and running.
Every game needs a hero, right? In this chapter, we'll be taking a look at every element that goes into making the first-person player character from input controls to cameras and colliders. Once you've learnt what goes into making him, you'll introduce the player character to your island and take a stroll around.
Games are all about interacting with a virtual world, so where would our character be without some in-game actions? In this chapter, I'll introduce you to collision detection and ray casting. We'll look at how we can combine these techniques with scripting and animation to transform our static building into one that responds to our player.
Giving your player a sense of achievement in your game is essential. To help with this, you'll need to remind them of actions they've taken so far in the game, and give them something to aim for. In this fifth chapter, we will construct what is often referred to as a Heads Up Display (HUD) with text and graphical displays that change dynamically as the user plays.
Having created a simple HUD, you'll create a short object-collection game, which will allow the player character to pick up batteries in order to gain access to the building on the island.
Almost every game scenario that you can imagine will involve creating or "spawning" objects in your environment. Known in programming terms as Instantiation, the creation of objects during the game's runtime is a crucial concept for every beginner developer to get to grips with.
Having created our collection game and building interaction in previous chapters, we'll be building upon the interactivity in our game by creating a basic target game, which will involve throwing objects at targets to unlock a part of our environment. This will not only teach you about instantiation, but also the crucial concept of using rigid body physics objects in your games.
What's a 3D game these days without some fancy graphic effects to wow the player? In this chapter, you'll be creating a log fire to keep our player warm — using two particle systems, one for flames and the other for smoke.
Using a Particle System, we'll look at how we can mimic the behavior of fire and utilize images for each particle to add realism; we'll finish by disabling the fire, giving the player something to aim for — getting it lit to keep warm!
Creating a professional, easy-to-navigate menu is a crucial part of making an enjoyable game product. What user is going to want to play your game if he or she can't even find the Start button? In this chapter, we look at the various ways of creating menus and other user interfaces for the player to interact with.
You will create menus using both GUI textures and the GUI class in order to create scalable interfaces that can be deployed on the desktop or the Web.
In game production, especially in Unity, you will reach a point at which you have just created some piece of interaction in your game that you're so pleased with, you want to add that extra polish to make it really stand out to the player.
In this chapter we'll take a look at further uses of sound, lighting effects, trail rendering, and other dynamic effects that are easy to implement, and make the difference between a simple working game and a polished final product.
In this chapter, we will look at how we can export your game for the Web and as a standalone project. We'll look at various different settings you will need to consider when you are preparing your finished product for your audience, such as graphical quality, control input, and more.
In this chapter, we will discuss the ways in which you should move on from this book, and how you can gather information from test users to improve your game. This will help you prepare your project to be tested by a wider audience to get feedback and make even better games!
An installed copy of the Unity software — a trial version is available from Unity3D.com
Internet connection in order to download supplied 3D models and other assets, available from PacktPub.com
An available 3D modelling package, although this is not essential. All materials used are provided as per above. If you are new to modelling, you may wish to download one of a few free applications that work well with Unity, such as Blender from Blender.org.
Having worked with Unity for the past few years as a tutor, I've found the main complaint that its users encounter is not with the software itself, but rather that there is a lack of introductory material for new users coming from a non-programming based background.
In the existing climate, this is, of course, rare; but with a tool such as Unity allowing such ease of production as it does, the importance of such a tutorial guide has become ever more pressing.
If you're a designer or animator who wishes to make their first steps into game development, or if you've simply spent many hours seated in front of video games, with ideas bubbling away in the back of your mind, Unity and this book could be your ideal starting point. I will assume no prior knowledge of game production and start completely from scratch, inviting you to simply bring with you a passion for making great games.
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: "We can include other contexts through the use of the include directive."
A block of code will be set as follows:
if(collisionInfo.gameObject.name == "matchbox"){
Destroy(collisionInfo.gameObject);
haveMatches=true;
audio.PlayOneShot(batteryCollect);
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 our text like this: "clicking the Next button moves you to the next screen."
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