Book Image

Unreal Development Kit Game Programming with UnrealScript: Beginner's Guide

By : Rachel Cordone
Book Image

Unreal Development Kit Game Programming with UnrealScript: Beginner's Guide

By: Rachel Cordone

Overview of this book

Unreal Development Kit is the free edition of Unreal Engine—the largest game engine in existence with hundreds of shipped commercial titles. The Unreal Engine is a very powerful tool for game development but with something so complex it's hard to know where to start.This book will teach you how to use the UnrealScript language to create your own games with the Unreal Development Kit by using an example game that you can create and play for yourself. It breaks down the UnrealScript language into easy to follow chapters that will quickly bring you up to speed with UnrealScript game programming.Unreal Development Kit Game Programming with UnrealScript takes you through the UnrealScript language for the Unreal Development Kit. It starts by walking through a project setup and setting up programs to write and browse code. It then takes you through using variables, functions, and custom classes to alter the game's behavior and create our own functionality. The use and creation of Kismet is also covered. Later, using replication to create and test multiplayer games is discussed. The book closes with code optimization and error handling as well as a few of the less common but useful features of UnrealScript.
Table of Contents (18 chapters)
Unreal Development Kit Game Programming with UnrealScript
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Time for action – Misleading errors


Sometimes error messages might seem a little misleading, as we'll see in this next experiment:

  1. Let's rewrite our PostBeginPlay function. We'll leave in our MyInt variable and use it for this experiment:

    simulated function PostBeginPlay()
    {
        if(UTGame(WorldInfo.Game != none)
            MyInt = UTGame(WorldInfo.Game).DefaultMaxLives;
    }
  2. Seems fine, but when we try to compile we get this error:

    [0004.84] Log: R:\UDK\UDK-AwesomeGame\Development\Src\BrokenGame\Classes\BrokenActor.uc(8) : Error, Bad or missing expression for token: UTGame, in 'If'

    What could this mean? It seems to be telling us that it doesn't know what UTGame is, even though it's a valid class. If we take a closer look at our if statement, we can see the problem:

        if(UTGame(WorldInfo.Game != none)

    I'm counting two open parentheses, but only one closed one. If we take the if part out of this line and examine it separately:

        UTGame(WorldInfo.Game != none)

    To the compiler, it looks like we're trying...