7.1. Oscars & Artificial IntelligenceInterim awards and introduction to game AI

1CSC2007 OscarsMid-way awards

2Submission with the most impressive/complex exploratory code

Submission with the best progress to date

Category One

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Category One: Nominees

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Category One Winners

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Most authentic rendition of a classic computer game

Most original/fun game design or game play idea

Game I least want to present at the Board of Examiners

Most comprehensive game design including development plan and contingency planning.

Team/Game with the best name

Team/Game with the most inappropriate name

Category Two

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Category Two: Nominees

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Category Two Winners

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8Introduction to Game AIIntroduction to game-oriented artificial intelligence

9Artificial Intelligence (academic vs. game)Artificial intelligence aims to develop machines that can perform human thinking tasks.Academic research is split into two camps:Strong AI creating systems that model human thought processesWeak AI creating working systems that need not be physiologically plausibleAcademic AI tends to focus on optimal problem solving.Game AI must work within tight computational constraints, i.e. effort vs. outcome is central.

10The aims of game artificial intelligenceThe aims of game-oriented AI can be summarised as follows. The AI must:appear intelligent, yet purposely flawed (i.e. beatable)have no unintended weaknesses (that can be repeatable exploited) provide an entertaining or engaging experienceperform within tight CPU/memory constraintsbe configurablenot keep the game from shipping

11The illusion of intelligenceMost people assess intelligence (or the lack thereof) on how an object behaves. Acting in a complex (human-like) manner is readily perceived as intelligence behaviour.

Aside: Describe the colour of square A? What colour is B?A is exactly the same colour as B!One means of enhancing game AI is to provide visual/auditory feedback on what the game object is thinking.Often simple or semi-random behaviour will be perceived/intepretated by the player as complex/intelligent.

Aside: Taken from Artificial Intelligence For Games Because the illusion of intelligence is subjective, sometimes this takes very little effort at all. The designers of the AI for Halo, for instance, discovered their playtesters could be fooled into thinking the AI agents were more intelligent simply by increasing the number of hit points required to kill them. For one test session they allowed the agents to die really easily (low hit points); the result was that 36 percent of the testers thought the AI was too easy and 8 percent thought the AI were very intelligent. For the next test session the agents were made harder to kill (higher hit points). After just this small change 0 percent of the testers thought the AI was too easy and 43 percent thought the AI was very intelligent!

12A practical definition of game AIGame AI is anything that contributes to the perceived intelligence of an entity, regardless of whats under the hood.

Aside: Searles Chinese Room argument

13Game AI (is it, or isnt it)Which of the following could be classified as providing an example of AI within the context of a game?Does a single if statement constitute intelligence?What about scripted behaviour?If an NPC selects which animation to play? (If this is done via a set of if statements?)Maybe path-finding?If game automatically generates an environment?

14Genre Specific AIThe forms of AI found within different types of (2D) game

15AI (in general)AI needs within the game can include:Perception determining what can be seen (other opponents, pick-ups, incoming projectiles, etc.)Steering basic character movementAction executing available actions, e.g. aiming, shooting, etc.Path-finding movement route planningDecision making determining what to do next (dodge, seek health, ambush, etc.). At higher levels this becomes tactical AI.

To do:Consider own game

16AI (side-on/top-down shooters)AI needs within the game can include:Perception detecting nearby objects, incoming projectiles, etc.Steering opponent movement, e.g. player tracking, projectile avoidance, etc.Firing basic control, firing towards player

Aside: AI within 2D shooters may be effectively nonexistent, i.e. relying on fixed patterns of movement and opponent numbers to provide challenge

17AI (driving)AI needs within the game can include:Perception detecting other trafficSteering driving line, cornering, breakingDecision making overtaking points, collision avoidance

Aside: GTA/Driver clones would also include AI routines to model other road traffic, etc.

18AI (platform)AI needs within the game can include:Perception determining actions/movement of playerSteering moving towards/away from playerShooting basic control, e.g. aiming

Aside: Platform games tend to have opponents which have predictable, easily understood behaviour. Challenge arises from the need to time jumps, shots, etc. to overcome such opponents.

19AI (real time / turn-based strategy)AI needs within the game can include:Perception determining what can be seen (other opponents, resources)Steering group movement, etc.Path-finding movement route planningTactical and Strategic Analysis determining overall strategy build, attack, etc.

Aside: AI in real-time games is mostly the same as in turn-based games. Real-time games must impose tight performance constraints on the AI.

20AI (beat-em-up)AI needs within the game can include:Decision making determining what to do next (block, back-up, attack, etc.).

Aside: The behaviour can be adaptive, i.e. reacting to the players patterns of behaviour

21AI (sport)AI needs within the game can include:Steering basic character movement, group movement, etc.Decision making determining what to do next, selecting plays, formations, etc. from an available playbookTactical Analysis determining play objectives

Aside: Sport AI has the benefit of drawing upon existing expert knowledge, but must return realistic, human-like behaviour

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Summary

To do:Think about the role and needs of AI within your gameRead about the Week 9 Alpha hand-in and plan what you hope to developToday we explored:

The role of AI within games and the constraints game AI must operate withinThe typical roles of AI within 2D game genres

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