My First Code

Created by Chris Linder (DemiurgeStudios^?) on 11-18-03 for 2226 builds. Last Updated by Michiel Hendriks, UT2003 -> UT2004.

Related Documents

MyFirstPawn, MyFirstController, MyFirstGameInfo, MyFirstHUD, NewProjectPreparation, GameAndAIHandout

Introduction

This document will go over the basics of what is involved with creating your own pawn class, player controller class, HUD, and game type. This document is only an overview and describes how the different classes interrelate; for more info on each class see their respective documents.

This example tries to be fairly basic but it still assumes some knowledge of UnrealScript and how networking "replication" is handled in the Unreal Engine. You should be able to jump right into this example and understand most of it but further reading would help. For more details on UnrealScript see the UnrealScriptReference. For more details on replication consider the NetworkingTome and the PlayerReplicationHandout.

Parts of the Example

Pawns

Pawns (any class that extends Pawn.uc) are Actors in the Unreal engine that move around on there own and are either controlled by a player, an AI, or an AI script (see Player Controllers below for more info). The avatar you control when you play UT2004 is a Pawn as are all the other players you see in the game be they bots or other people in a net-game. Non-Player Characters (NPCs) such as those in any single player game are also Pawns. Movers and rockets are examples of things that move around and are not Pawns. This document will focus on the Pawn you control as you play the game.

The pawn you control when you play can be specified in User.ini or at the command line (see the MyFirstPawn document for more details). The pawn can be changed without altering any part of the engine or even changing any code. Any pawn can be used with the given player controller but it may not work quite right; it should still move around the world though. If there are a set of pawns designed to work with the given player controller then these pawns can be swapped and substituted with no problem at all. The MyFirstPawn document has two pawns, a girl and a guy, that can both be used with the default player controller.

Player Controllers

Controllers (any class that extends Controller.uc) control Pawns in the Unreal engine. Controllers can be AIs, like Bots in UT2004, or controllers can be an interface to a human player that allow a person to control a pawn. Controllers can control any pawn which is useful because it makes it very easy to use a single pawn as a Bot or as player's avatar.

Player controllers (any class that extends PlayerController.uc) are the controllers that serve as the interface from a human player to a pawn. The player controller to use is specified in the GameInfo. You therefore need to change code to use a new player controller.

See the MyFirstController example for more details.

GameInfos

GameInfos (any class the extends GameInfo.uc) are how game types are created. DeathMatch and CTF are both examples of game types. The game info is accessible from most classes so those classes can query about the state of the current game. Along with creating functions and variables that define a game, the game info defines how players enter the game, restart the game, logout, etc...

GameInfos also specify what the player controller class is and what the HUD class is. Specifying the controller and HUD is the primary use of the game info in the MyFirstGameInfo example. The game info in the example does not create any new game type at all.

HUDs

HUDs (any class the extends HUD.uc) draw the Heads Up Display to the screen. See the HeadsUpDisplayReference and the HeadsUpDisplayTutorial for more information on what HUDs can do. HUDs are specified in the GameInfo by class name. Also specified in the GameInfo is the ScoreBoard which shows the names and scores of everyone in the current game. The ScoreBoard is displayed instead of the HUD when you press 'F1'. The ScoreBoard is closely related to the HUD but it is its own class which extends ScoreBoard.uc.

See the MyFirstHUD example for more details on HUDs and ScoreBoards.

Installing the Example

There are two installs for the MyFirstCode example. The pawns in MyFirstPawn can be installed independently without any other code. See the MyFirstPawn document if you just want to install the pawns. The other examples such as player controller, HUD, and game type all inter-depend on each other as well as depending on the pawn example and therefore must be installed as a block. The rest of this section will go over how to install the block of examples which includes the pawn classes, the player controller, the HUD, and the game type.

Unreal Runtime

If you are using the Runtime, simply download the MyFirstExample.zip, unzip it and run MyFirstExample.urm. If you can not simply run MyFirstExample.urm this probably means you unchecked the "Runtime modification association" box when installing the Runtime. In that case you will have to follow the steps below:

1. Open MyFirstExample.zip and extract MyFirstExample.urm to the "System" directory of the Runtime.
2. Open a command prompt in the "System" directory of the Runtime.
3. Type "setup install MyFirstExample.urm"

In either case, follow the instructions presented in the install window and this will install this example for the Runtime.

Once the example is installed you must edit INI files to use the example. First edit User.ini to specify the type of pawn to use. In the [DefaultPlayer] section of User.ini set Class as follows:

Class=MyFirstExample.ExampleBoy
- or -
Class=MyFirstExample.ExampleGirl

Next you need to edit UE2Runtime.ini. In the [Engine.Engine] section change DefaultGame and DefaultServerGame as follows:

DefaultGame=MyFirstExample.ExampleGameInfo
DefaultServerGame=MyFirstExample.ExampleGameInfo

You don't need to change DefaultServerGame if you are only using single player but then again if you are only using single player, changing DefaultServerGame doesn't matter.

Now just start the Runtime and pick and map and you are good to go. The pawn, controller, HUD, and GameInfo will all be used

Code Drop, UDNBuild, UDNBuildOff

If you are using the UDNBuild or UDNBuildOff, download MyFirstExample_UDNBuild.zip and unzip it in your build of the engine.

If you are using the 2226 code drop, download MyFirstExample_CodeDrop.zip and unzip it in your build of the engine, or the MyFirstExample_CodeDrop3323.zip for newer builds.

Once the example is unzipped you must edit INI files to use the example. First edit User.ini to specify the type of pawn to use. In the [DefaultPlayer] section of User.ini set Class as follows:

Class=MyFirstExample.ExampleBoy
- or -
Class=MyFirstExample.ExampleGirl

Next you need to edit <YourGame.ini> (UT2004.ini for example). In the [Engine.Engine] section change DefaultGame and DefaultServerGame as follows:

DefaultGame=MyFirstExample.ExampleGameInfo
DefaultServerGame=MyFirstExample.ExampleGameInfo

You don't need to change DefaultServerGame if you are only using single player but then again if you are only using single player, changing DefaultServerGame doesn't matter.

Now just start the game and pick and map and you are good to go. The pawn, controller, HUD, and GameInfo will all be used

Using this Example in Net-Play

If you would like to use this example in net play you have to do a few things on the computer hosting the game.

First edit <YourGame.ini> (UE2Runtime.ini or UW.ini for example) and include "MyFirstExample" in your ServerPackages list. The ServerPackages list is in the [Engine.GameEngine] section of the INI file and you can just add the following line to that section:

ServerPackages=MyFirstExample

Next you must rebuild the MD5 database. Do this by opening a command prompt in the "System" directory of your build of the engine and then type:

UCC MASTERMD5 -c *.U

Now you can host a game and other people can connect to it and you can all run/fly/swim/dance around together. You can host a game by typing the following at a command prompt in the system directory:

UE2Runtime <YourMap> -server
- or -
UW <YourMap> -server

To connect to a server running this example you must have installed the example as described above in the Installing the Example section. Then just run the game and bring up the console (press the '~' key) and type: "open <IP Address of Server>", for example "open 192.168.1.112".

Making Changes to the Example - Using the Example in UnrealEd

If you wish to make changes to the given code or you want to place ExamplePawns in UnrealEd, you will have to add "MyFirstExample" to the EditPackages lists in <your_game>.ini (UW.ini or UE2Runtime.ini for example). Do this by opening your INI file and doing a text search for "EditPackages" and then add the line "EditPackages=MyFirstExample" to the bottom of the list. There are two lists so make sure to add the line to both lists. If you are making changes to the code you can recompile the changes you made by deleting the existing MyFirstExample.u file in the system directory and typing "ucc make" at the command line.