To make the ‘Cuda its own object or Actor in the world of Unreal, you need to create a class for it in UnrealScript. UnrealScript is a full-featured programming language “created to provide the development team and the third-party Unreal developers with a powerful, built-in programming language that maps naturally onto the needs and nuances of game programming.”^[18] You can find many UnrealScript references on the Web. Two good ones are http://udn.epicgames.com/Two/UnrealScriptReference and http://udn.epicgames.com/Two/MyFirstCode.

To create a new class, you first need to create a new UnrealScript package. From your Unreal Tournament 2004 directory (generally C:\UT2004), create a new directory. The name of this directory will be the name of your package; for this example, let’s call it CudaExample. In the CudaExample directory, create a subdirectory called Classes, and in Classes, create a text file called CudaCar.uc.

You can use any text editor to create and edit this file. Notepad will work, but you might consider an editor geared toward editing code. Microsoft Visual Studio works well, especially since it can do syntax highlighting on UnrealScript files if you tell it to treat them like C++ files. You might also consider using the Epic’s free Unreal Development Environment (UDE).

Once you’ve created CudaCar.uc, open it up, and declare the CudaCar class like so:

class CudaCar extends ONSRV;

This line means that your CudaCar example is based on the ONSRV class, the preexisting Scorpion vehicle in Unreal Tournament 2004. For now, the example car will behave and look exactly like the Scorpion. Later, you’ll make your class use the ‘Cuda model, but that’s the only line you need to define the class.

For the CudaCar example to work, you also need a factory to produce instances of your CudaCar. Vehicle factories create vehicles at the beginning of a game and when old vehicles are destroyed. In the same way you created CudaCar.uc, create CudaCarFactory.uc as follows:

class CudaCarFactory extends ONSVehicleFactory;

defaultproperties
{
    // mesh for factory (only seen in the Editor)
    VehicleClass=Class'CudaExample.CudaCar'

    // type of vehicle this factory spawns
    Mesh=SkeletalMesh'CloneBanditsVehicles_K.HotRod'
}

Now open up UT2004.ini in the System subdirectory of your UT2004 directory. Search for the text EditPackages, and add the line:

               EditPackages=CudaExample

to the bottom of the list. Now you can compile the CudaExample package.

Open a command prompt in the System subdirectory, and type ucc make. This command compiles any package in the EditPackages list that doesn’t have a *.u UnrealScript package file. If everything works, you’ll end up with a new CudaExample.u file. If you make changes to CudaCar.uc (or any other UnrealScript file in your package), you can recompile your code by deleting the existing CudaExample.u file and running ucc make again.

Now you have two cars that act exactly the same. Let’s justify this work by making the new car class use the ‘Cuda model. Edit the defaultproperties of the CudaCar to add the following to your CudaCar.uc file:

defaultproperties
{
    // Barracuda Mesh
    Mesh=SkeletalMesh'CloneBanditsVehicles_K.HotRod'

    // Don't use team skins
    RedSkin=None
    BlueSkin=None

    // Weapon
    DriverWeapons(0)=(WeaponBone="gunRTmount")

    // Vehicle Name
    VehicleNameString="Barracuda"
    VehiclePositionString="in a Barracuda"

    // Driver Position
    DrivePos=(X=0.0,Y=-30.0,Z=35.0)

    // Lights
    HeadlightProjectorOffset=(X=139,Y=0,Z=6)     // headlight projector
    HeadlightCoronaOffset(0)=(X=135,Y=44,Z=0)    // headlights
    HeadlightCoronaOffset(1)=(X=135,Y=-44,Z=0)
    HeadlightCoronaOffset(2)=(X=10,Y=33.5,Z=40)  // roof lights
    HeadlightCoronaOffset(3)=(X=12,Y=25,Z=42)
    HeadlightCoronaOffset(4)=(X=11,Y=14.5,Z=40)
    BrakeLightOffset(0)=(X=-134,Y=39,Z=6)        // tail lights
    BrakeLightOffset(1)=(X=-134,Y=-39,Z=6)

    // Wheel and wheel bones info

    // right rear tire
    Begin Object Class=SVehicleWheel Name=RRWheel
        bPoweredWheel=True
        bHandbrakeWheel=True
        BoneName="tire02"
        BoneRollAxis=AXIS_Y
        BoneOffset=(Y=20.000000)
        WheelRadius=24.2000000
    End Object
    Wheels(0)=SVehicleWheel'RRWheel'

    // left rear tire
    Begin Object Class=SVehicleWheel Name=LRWheel
        bPoweredWheel=True
        bHandbrakeWheel=True
        BoneName="tire04"
        BoneRollAxis=AXIS_Y
        BoneOffset=(Y=-20.000000)
        WheelRadius=24.200000
    End Object
    Wheels(1)=SVehicleWheel'LRWheel'

    // right front tire
    Begin Object Class=SVehicleWheel Name=RFWheel
        bPoweredWheel=True
        SteerType=VST_Steered
        BoneName="tire"
        BoneRollAxis=AXIS_Y
        BoneOffset=(Y=20.000000)
        WheelRadius=20.000000
    End Object
    Wheels(2)=SVehicleWheel'RFWheel'

    // left front tire
    Begin Object Class=SVehicleWheel Name=LFWheel
        bPoweredWheel=True
        SteerType=VST_Steered
        BoneName="tire03"
        BoneRollAxis=AXIS_Y
        BoneOffset=(Y=-20.000000)
        WheelRadius=20.000000
    End Object
    Wheels(3)=SVehicleWheel'LFWheel'
}

The Mesh=SkeletalMesh'CloneBanditsVehicles_K.HotRod' line sets the mesh of the vehicle to that of your ‘Cuda model instead of the Scorpion model. Given that you’ve changed models, you need to change a few other things, too. First off, you need to prevent the red and blue team skins from applying to this model, because those textures are entirely different. Do this by setting the RedSkin and BlueSkin to NONE. Next, given that all the bone names are different, you need to reassign things to use valid bone names. The gun, for example, attaches to the bone named gunRTmount. The same reassignment goes for the wheels, done with the Wheels array at the bottom of defaultproperties.

It is helpful to change several other properties such as the name of the vehicle (VehicleNameString and VehiclePositionString) and where the driver sits (DrivePos). Consider also adjusting the position of the headlights, taillights, and headlight projector in the Lights block in defaultproperties. The CudaCar will still work without these changes, but these adjustments are more aesthetically pleasing. Finally, the Scorpion blades will not exist on the CudaCar, because there are no blades on the ‘Cuda model. However, the blades will still make noise.

Now that you’ve created your own class and set it to use the new model, use UnrealEd to place the car in a map. Run UnrealEd by typing UnrealEd at a command prompt in the System directory, double-clicking on the UnrealEd icon, or selecting UnrealEd from the start menu. Once in UnrealEd, open up any Onslaught map. (These maps all start with ONS- and work with the vehicle-focused Onslaught game in Unreal Tournament 2004.) Open the Actor Classes browser, and select CudaCarFactory, as shown in Figure 7-10.

Figure 7-10. Selecting the factory to place

Right-click somewhere on the terrain in the map, and select Add CudaCarFactory Here, as seen in Figure 7-11.

Figure 7-11. Placing the car factory on a map

This action places a factory for your new car class in the map. At this point, save your map. Go to the file menu and select Save As.... Now, enter your map name, making sure to start it with the prefix ONS- (for example, ONS-CudaExample), and click Save.

Now your map will appear in the map list in Unreal Tournament 2004 when you select the Onslaught game type from either the Host Game or Instant Action main menu options. You can also test your map by clicking the Play Map! button in UnrealEd to launch the map. Once in the map, make your way to where you placed the car, get in, and drive! You should look as cool as Figure 7-12.

Figure 7-12. Driving away in the ‘Cuda model