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 – Using function parameters


Time to pass some variables around! Let's start with the PostBeginPlay function in our AwesomeEnemySpawner class.

  1. We haven't defined the PostBeginPlay function for our AwesomeEnemySpawner class, so let's do it now, and let's add an int to the function parameters:

    function PostBeginPlay(int MyInt)
    {
    }

    Compile the code. Uh oh, an error right out of the gate:

    Error, Redefinition of 'function PostBeginPlay' differs from original; different number of parameters

    This is the most important thing to remember about function parameters. Once a function is defined, if it's ever used in a subclass, then it must have the exact same number and type of parameters as the original. The names of the variables don't have to be the same, but if the original function has a bool and an int, any subclasses must have a bool and an int in their parameters.

  2. Let's take a look at an example of this. We've been using the Tick function a lot. If we look in Actor.uc where it's declared...