Game AI Fundamentals

What is Artificial Intelligence (AI)?•Not easy to answer…

•“Ability of a computer or other machine to perform those activities that are normally thought to require intelligence” (from dictionary)

•“Process” or “science” of creating intelligent machines

•Artificial “brains” that carries out intelligent behaviour

Perspectives of AI

•People study AI to:▫Gain insight into nature of human

intelligence▫Create machines that exhibit some form of

intelligence•So…do game developers need to STUDY

AI?

How do we know…

•…if a machine is “intelligent”?▫How close is it to human intelligence?▫Requires the machine to have conscience

and emotions?▫Ability to solve a problem that humans can

solve?▫Ability to learn and adapt to new situation?

•Turing Test

Weak AI vs. Strong AI

•Strong AI – Produce machines that with an intelligence that match or exceed that of humans

•Weak AI – Produce machines that are able to “act” intelligently

Chinese Room Argument

• Does the machine literally understand Chinese? (Strong AI)

• Is the machine simulating the ability to understand Chinese? (Weak AI)

Deterministic vs. Nondeterministic•Deterministic AI

▫Behavior is specified and predictable, no uncertainty

▫Fast, easy to implement, Gameplay limitations

•Nondeterministic AI▫Behavior has a degree of uncertainty, less

predictable, learn and extrapolate from experience

▫More burden of implementation and testing ▫Gameplay evolution, emergent behavior

Established Game AI

1. “Cheating” – most widely used technique, abusing this can destroy gameplay.

2. Finite state machines3. Fuzzy logic or Fuzzy state machines –

improve unpredictability, reduce burden of too many rules

4. Pathfinding – simple shortest path navigation, terrain-based/obstacle-based extensions

5. Rule-based, Probability-based decision making

Millington’s Model

Future of Game AI

•The next big thing: Learning – Bayesian techniques, NN, GA▫NPC behaviors are nondeterministic▫Game AI can evolve, learn and adapt the

more it’s played▫Implementation/debugging challenge

•Artificial life and other Emergent AI