This example is installed by Pogamut UT2004 installer. In NetBeans click New Project -> Maven -> Project From Archetype -> Local Archetypes Catalog and select 00-empty-bot-archetype project. Moreover, as Pogamut 3 has been fully mavenized, you can try and run this example even without installing the Pogamut NetBeans plugin. However in that case you won't be able to use visualization as this is a part of Pogamut NetBeans plugin. To set up this example follow up the steps in Pogamut 3 with Maven Quickstart Tutorial and in the last step fill up following information into Maven Archetype dialog:

For UT2004 example:

For UDK example only change Group Id: to cz.cuni.amis.pogamut.udk.examples and Version: 3.2.5-SNAPSHOT . The rest remains the same.

Note: You will find up-to-date list of available archetypes in Pogamut Maven archetypes catalog

Notice that the project's node in Projects tab is in bold, this means that the Run Main Project (F6) and Debug Main Project (Ctrl + F5) buttons are linked to this project. Before we start your first bot, we have to launch the Unreal Tournament dedicated server - an environment simulator that Pogamut and the bot will connect to. You have two options how to start the server:

Now the server is running and the IDE knows how to connect to it. You can start the bot by pressing F6 ( Run Main Project ). Alternatively, you can simply right click the main bot class and select Run File or select the project and click Run. If everything works fine, the bot will connect to the server and begin execution. After starting, the bot will appear under the Local UT node in Pogamut bots folder. It will be represented by a node named EmptyBot. If you select the bot's node, you will see some additional information about the bot in Properties window (Window → Properties). Agent3D section shows properties defining bot's position in the space, Agent configuration section enables you to change bot's behavior/abilities (e.g. if the bot will be able to use raycasting, if it will automatically pick up items etc.). You will see that the bot is standing still, no movement, no rotation, after all, that's what it was designed for.

To see how the bot is doing in the game you will have to start the Unreal Tournament (UT) client, you can:

When starting the UT for the first time it will open in a full screen mode, when developing bots you will often want to see both the Netbeans window and the UT. You have two options - use two monitors or configure UT to start in windowed mode, you can do this from main menu of UT Settings → Display tab → Resolution panel → uncheck the Full Screen checkbox.

Inspecting the bot directly in UT is a very handy debugging tool. You can see, where the bot exactly is, whether it has stuck etc. Gamebots, Pogamut's extension of the Unreal Tournament, also adds some in game visualization features that can be useful when observing the bot.

Once the UT has connected to the game, press the left mouse button to view the bot. Also notice the green text in the upper half of the screen labeled GAMEBOTS 2004 HUD HELP (press ALT + H to trigger HUD help on and off). You can try some of the listed functions, but we will address them later on.

Note:If the UT window seems to be not reacting to your key presses, try to press ALT key again - sometimes when switching between windows through ALT + TAB, the ALT button is left hanging in UT2004 with UT2004 thinking you are still pressing it even if you are not.

Now return back to the Netbeans (if UT was in full screen mode use ALT + TAB). We will go through bot's source code in order to describe its basics.

The EmptyBot extends UT2004BotModuleController class, this is declared by line:

public class EmptyBot extends UT2004BotModuleController

UT2004BotModuleController is a base bot class that will suit most situations. UT2004BotModuleController class has several methods that have to be overridden by the EmptyBot and by any other bot extending this class.

These methods are:

Sequence of calling these methods is:

Let's explore methods implemented in this example. First is getInitializeCommand():

    public Initialize getInitializeCommand() {
        return new Initialize().setName("EmptyBot");
    }

In this method an Initialize object is created, a bot's name is set and the initialized object is returned to the rest of Pogamut platform. Note that all setters in all Pogamut commands always return the same object, so you may chain the setters calls.

        new Initialize().setName("EmptyBot").setTeam(0);
    

Second method is botFirstSpawn(GameInfo gameInfo, ConfigChange config, InitedMessage init, Self self):

    public void botFirstSpawn(GameInfo gameInfo, ConfigChange config, InitedMessage init, Self self) {
        // Display a welcome message in the game engine
    	// right in the time when the bot appears in the environment, i.e., his body has been just spawned
    	// into the UT2004 for the first time.
        body.getCommunication().sendGlobalTextMessage("Hello world! I am alive!");

        // alternatively, you may use getAct() method for issuing arbitrary {@link CommandMessage} for the bot
        getAct().act(new SendMessage().setGlobal(true).setText("And I can speak! Hurray!"));
    }

The "Hello world!" message is printed there. Note that the body is the gateway for the most commands you may issue to the bot to Unreal Tournament. These commands are grouped together in several categories, like body.getCommunication(). All commands are well documented, so you can receive contextual help in NetBeans while coding.

Alternatively you can use the basic command interface accessed through getAct() method to issue commands. The getAct() method returns object implementing IAct interface that defines act(CommandMessage command) method. The act() method is the gateway for issuing actions represented by CommandMessage objects. SendMessage is a command sending message to a global chat channel - the constructor. Notice that the object is created and it's name property is set in only one line. The setText() method returns the instance on which it has been called, so more properties can be set in a chain e.g. new SendMessage().setGlobal(true).setText("And I can speak! Hurray!").

Last method we will describe in this section is main(). This is the first method called when you execute the bot program (like in any other Java program). This method is responsible for instantiating the bot and connecting it to the environment. Bot runner class facilitates bot execution:

    public static void main(String args[]) throws PogamutException {
    	// wrapped logic for bots executions, suitable to run single bot in single JVM
    	new UT2004BotRunner(EmptyBot.class, "EmptyBot").setMain(true).startAgent();
    }
     

Note that setMain(true) is setter that should be used only in global main methods (i.e., public static void main(String args[])) so the Pogamut platform correctly terminates itself after the end of the bot run. Otherwise the JVM should not exit itself ... blame the JMX guys! Not us :-) So the rule of thumb, you're in main method, use setMain(true), you're starting the agent from different method, do not use it.

The logic() method will be described in the next section.

Two features that you will find handy during parameterization and evaluation of the bot are logging and introspection.

Logging is a mechanism for tracing program's execution by printing messages - it can be used both for debugging (multi threaded applications are often hard or impossible to debug using breakpoints) and evaluation (you can process logs of bot's activity and utilize some statistical software).

Introspection is designed to ease the bot's parameterization. It is often needed to adjust multiple behavior parameters at runtime and you will probably end up creating your own GUI (graphical user interface) for this purpose. In introspection, you just annotate desired variables with @JProp annotation and they will be accessible via the Netbeans GUI.

Let's look how logging and introspection works in EmptyBot example. First start the bot (F6), then have a look on it's source code. In the initial section several variables annotated with the @JProp are defined.

    @JProp
    public String stringProp = "Hello bot example";
    @JProp
    public boolean boolProp = true;
    @JProp
    public int intProp = 2;
    @JProp
    public double doubleProp = 1.0;

Now expand bot's node under the UT server node (in Services tab), you will see two new nodes - Logs and Introspection. After selecting the Introspection node the annotated variables will be shown in the Properties (Ctrl + Shift + 7) window. Note that the intProp variable is being continuously updated. New values of variables can be also set in this window.

Last non-empty method is logic(). There a simple follow player behavior is specified. The bot first checks whether he sees someone and if yes he tries to go to that player location and if not and he remembers some player he was following before, he goes to the last known spot of the player using advanced map navigation object pathExecutor.

    public void logic() throws PogamutException {
        if (players.canSeePlayers()) {
            lastPlayer = players.getNearestVisiblePlayer();
            move.moveTo(players.getNearestVisiblePlayer());
        } else {
            if (lastPlayer == null) {
                //we don't see any player and we don't even remeber lastPlayer - we will turn around
                move.turnHorizontal(30);
            } else {
                if (lastPlayer.getLocation().getDistance(info.getLocation()) < 200) {
                    //if we are close we will turn to the spot and forget the lastPlayer
                    move.turnTo(lastPlayer.getLocation());
                    if (info.isFacing(lastPlayer.getLocation())) {
                        lastPlayer = null;
                    }
                } else {
                    //if we are not closed we tell pathExecutor we want to go there - if
                    //we are not going there already
                    if (this.pathExecutor.isExecuting()) {
                        // WAIT TILL WE GET THERE
                    } else {
                        this.pathExecutor.followPath(
                                this.pathPlanner.computePath(
                                info.getLocation(),
                                lastPlayer.getLocation()));
                    }
                }
            }

        }
    }	  
	  

Note that you can observer Pogamut logs accesible by getLog() method under bot's Logs node.