X9

Now is the time to delve into something easy but fun and visually satisfying. Every game with a mouse needs a cursor. Now I tried several ways of getting a simple mouse cursor to work, but did not end up with good results. UDN has a tutorial on mouse cursor but I was unsuccessful in implementing it properly since I think its for Unreal tech 2. You can find this tutorial here : http://udn.epicgames.com/Two/MouseCursorInterface.html for reference. Anyhow, our cursor will be superior

 

Create a new file and call it MeshMouseCursor. Make it extends Actor. Actors are the base classes for things that have a 3d representation in your game world. Almost all classes are derived or extended if you prefer from the Actor base class.

This class should look like this :

 

class MeshMouseCursor extends Actor;

var() StaticMeshComponent Mesh;

DefaultProperties
{
	Begin Object Class=StaticMeshComponent Name=MarkerMesh
		BlockActors=false
		CollideActors=true
		BlockRigidBody=false
		StaticMesh=StaticMesh'WP_RocketLauncher.Mesh.S_WP_RocketLauncher_Exhaust'
		//Materials[0]=MaterialInterface'EngineMaterials.ScreenMaterial'
		Scale3D=(X=2.0,Y=2.0,Z=2.0)
		Rotation=(Pitch=-16384, Yaw=0, Roll=0)
	End Object
	Mesh=MarkerMesh
	CollisionComponent=MarkerMesh
	Components.Add(MarkerMesh)
}

Now the concept of Objects in DefaultProperties are beyond the scope of the tutorial. You should know that they represent components attached to classes. If you have some knowledge of Unity3D they are the same or so then Unity components. If you are familiar with C#, think of them like a button on a form. In this particular exemple I used the RocketLauncher exhaust mesh

I scaled it to twice its size in all axises and rotated so the fire will go up. This makes our 3d cursor, you can change the mesh and play with it, I used a common static mesh that is shipped with UDK just to let it be compilable out of the box. I also commented the Material entry because this comes from a copy/paste of some component in the UTGame and our material is set for our Rocket exhaust automatically.

Wiring the Mouse cursor

 

Go back into your IsometricGamePlayerController class. Add a new variable after the TraceActor variable :

var MeshMouseCursor MouseCursor; //Hold the 3d mouse cursor

Return to IsometricGamePlayerController::PostBeginPlay() function. We need to spawn the mouse cursor before the game fires up. This is the function that we will use, add this after the Log(“I am alive…” :

simulated event PostBeginPlay()

{

super.PostBeginPlay();

`Log(“I am alive !”);

MouseCursor = Spawn(class‘MeshMouseCursor’, self, ‘marker’);

}

Now the mouse cursor will show up, but it will be located in nowhere land. We should address this, lets make the cursor follow the mouse each frame

 

Add the following function to that gets executed each frame :

 

event PlayerTick( float DeltaTime )
{
	super.PlayerTick(DeltaTime);

	//Set the location of the 3d marker that moves with the mouse.
	MouseCursor.SetLocation(MouseHitWorldLocation);
}

Compile and run, you should end up with something like this :

 

Adding Trace for actors

 

Remember the TraceActor variable. We could do something with it, now that we have a visible mouse cursor.

 

Add the following variables on top of MyHud class :

var FontRenderInfo TextRenderInfo; //Font for outputed text to viewport

Lets then override the DrawHUD function to display what object class lies under the mouse cursor :

/**
 * This is the main drawing pump.  It will determine which hud we need to draw (Game or PostGame).  Any drawing that should occur
 * regardless of the game state should go here.
 */
function DrawHUD()
{
	//local Vector Direction;
	local string StringMessage;

	//Display traced actor class under mouse cursor for fun 
	if(IsometricGamePlayerController(PlayerOwner).TraceActor != none)
	{
		StringMessage = "Actor selected:"@IsometricGamePlayerController(PlayerOwner).TraceActor.class;
	}

	// now draw string with GoldColor color defined in defaultproperties. note you can
	// alternatively use MakeColor(R,G,B,A)
	Canvas.DrawColor = MakeColor(255,183,11,255);
	Canvas.SetPos( 250, 10 );
	Canvas.DrawText( StringMessage, false, , , TextRenderInfo );
}

The StringMessage has a concatenation with the @ inside, what it does is make a space and spit out both the text and the value of TraceActor.class. This is nice to remember when outputing traces in log. You can output pretty much all classes and values this way.

This closes this chapter for the mouse, next we will introduce basic movement.

 

Get source code to chapter 2

 

 

Chapter 3 – Making the pawn move to our will