Artificial Intelligence Beginning

Download Code File

I was looking for a way to make Kork a little more responsive and aggressive. To which end I have come up with the following AI scheme in scripting.

I have created a simple system that allows the designer to drop markers in the game map that will mark where patrolling bots will start out. When the mission is loaded, the markers are detected and bots are spawned at the
marker locations. The markers are then hidden from view.

The markers themselves can be given two dynamic variables in the map editor. The first is 'respawn' which will determine whether a bot respawns or not. The second variable is 'pathname' which should be set to a valid path on the map. (If no path is set the bot acts as a stationary guard.)

The bots will patrol the paths, routinely scanning for nearby clients to target.

The bots have an attention setting. How often they scan is determined by their attention level. The bots get more sluggish (freeing up processor time) when targets are too far away. Conversely, the bot becomes incrementally more attentive as targets come within range, and further aware as targets come into sight.

When a target is found in range and in sight the bot will shoot at the target. The firing sequence is a step of scheduled calls that call for a firing cycle, a trigger down cycle, and a firing delay to control bot rate of fire.

When a bot is attacked it's field of vision is temporarily increased to a 360deg field of vision - to emulate looking around to see what happened. The bot's attention level is also set to make it think at it's fastest rate when attacked.

In my code I wiped out using AIManager, and placed all of the AIManager code in a seperate file called AIManger.cs - which I don't load. I don't use it - because each bot thinks individually based on it's attention level.

To implement this version of AIPlayer the following changes need to be made.

1. Back up your original game.cs, player.cs, and AIPlayer.cs

2. In game.cs: The section for function StartGame needs to modified the following ways:
Delete the following lines.

// Start the AIManager
   new ScriptObject(AIManager) {};
   MissionCleanup.add(AIManager);
   AIManager.think();

and add this in it's place:

AIPlayer::LoadEntities();

3. In player.cs in the code for Armor::Damage modify the lines

// Deal with client callbacks here because we don't have this
// information in the onDamage or onDisable methods
   %client = %obj.client;
   %sourceClient = %sourceObject ? %sourceObject.client : 0;

   if (%obj.getState() $= "Dead")
      %client.onDeath(%sourceObject, %sourceClient, %damageType, %location);

to read:

// Deal with client callbacks here because we don't have this
// information in the onDamage or onDisable methods
%client = %obj.client;
%sourceClient = %sourceObject ? %sourceObject.client : 0;
     
if (%obj.getState() $= "Dead")
{
   if(%obj.isbot == false)
   {
     %client.onDeath(%sourceObject, %sourceClient, %damageType, %location);
   }
}

4. Replace AIPlayer.CS with the code from the file newaiplayer.cs
5. Load your map - Stronghold as an example. Kork should be missing.
6. Go into the map editor. (F11) Then go into the Editor Creator (F4)
7. Under Shapes there should be a new drop down called AIMarker, under that a new item called AIPlayer.
8. Create a new AIPlayer marker.
9. Select your marker, position it where you like and hit (F3) to modify the marker.
10. Create a new dynamic variable called 'pathname' and set its value to 'path1'
11. If you want to override the default respawn value - create another dynamic variable called respawn and set it's value to true or false.
12. Update your item by clicking 'APPLY' - very important and easy to miss step.
13. Save your mission and reload it.

A bot called Kork1 should appear and be following the usual path. Kork1 should shoot at you if you are in front of him, and within range.

I hope the resource helps other people get up and running with some AI code in their game.

I'd like to thank the other members of this website whose code has been used in several places in the script above.