Application of AI techniques for Computer Games BSc Computer Games Programming, 2006 Julien Delezenne GAMES ARTIFICIAL INTELLIGENCE

Overview of the demo

In-game editor

Pathfinding demo

Design The AI component is part of the game engine Contains a generic pathfinding system Object-oriented state machines Data-driven with the reflection system

AI and architecture AI can be divided in two parts –The game object system –The AI techniques The object system becomes very complex in commercial games AI techniques need to be integrated in a flexible way

Game system

Reflection For each game entity: –Instantiation from its name –Exposition of its properties –(De)Serialization including with files such as XML (used in the demos) –Editable attributes in the editor. The property grid of the editor is generated automatically

Abstract controller Two types of controllers –Player –AI Only the input is different The game logic should only know about the abstract controller

AI techniques Game developers always have: –A* for pathfinding –FSM for decision-making They are the two techniques of the stealth demo in a game environnment

Pathfinding F.E.A.R. Environnment represented as a graph A* is independent of the environnment C&C Generals

Pathfinding A* is divided in three modules –Map –Goal –Storage The client application implement these objects The A* algorithm will send request to them

Pathfinding

State machine Object-oriented States are independent of each others State changes are requested In the demo, the state machine is mostly driven by the the field of view of the characters

State machine

Results Actual game demo achieved using the two most common AI tehcniques: A* and FSM in a game scenario

Conclusion Pros –Objectives achieved –Overall methodology –Reflection system Cons –Data-driven system not complete –Some performance issues –Need different behaviours –Need an event-system

Future enhancements Scripting More behaviours Agents’ memory Dynamic pathfinding Navigational meshes More advanced Toolsets …