AIWeek 5

GAM 224

Outline

Announcements Final Project Demos Discussion Break Lecture

AINarrative

Announcements

Advising week Game assignments available Readings

reorganized a little for the new book

Final Project

Game concept document Parts

Game overviewMechanicsResourcesCharacters and StorySample Level

Final Project 2

Team project3 or 4 membersgroup authorship of overvieweach member will be primary author of

one other section

Final Project 3

4 Milestones 2/7 (next week)

Sort 9-12 game ideas Adopt game idea

2/21 Design overview draft (3-4 pages) Describe gameplay, context, key features. Why would someone want to play it?

2/28 Resource inventory

Homework #2

Demos

Final Fantasy Tactics (Miranda) Paper Mario (Bubon) Fable (Summers) Tales of Symphonia (Ballerini)

AI

"Physics" of non-player characterssimulating the opponentsimulating other characters

In some games it is the whole pointclassic strategySims

Artificial Intelligence

Broad field of study1950s: how to make computers think

like people Now

how to make computers less stupid

Game AI

Uses very little from AI researchtoo slowfocused on different problems

Main issue"planning"

• how to get characters to act believably

Planning

A planning problemCurrent stateEnd stateKnown operations

• preconditions• postconditions

Construct a sequence of operations to transform

current state to end state

Example

Current state player is alive

End state player is dead

Known operations move around use machete

• precondition: must be near target• postcondition: target is dead

Means-ends analysis

Work backwards from desired goal to current state

Exampleto use machete, must be near playerto get near player, moveetc.

Problemthe world changes all the time

Modern planning

Much more complex Integration of

actingsensingchoosingprioritizingetc.

Overkill for games

Typical game AI tasks

Character behaviorsusually scripted actions

Route findingmany games

Resource managementin strategy games

Modeling character relationshipsin some RPGs, some strategy games

Goals for AI

Provide player with challenge Make a good game experience May go against "intelligence"

Issues

Simulate or script?as in physics

Opponent should not make obvious errors

Opponent should not be totally predictable

Example

Simulation when player is firing, construct a line-of-sight map

from player's position. Find area outside of line-of-site especially if it is large and close

Script have predefined "hiding" zones when attacked go to the nearest location

In-between have predefined "hiding" zones calculate which is in the line-of-sight go to closest re-evaluate line-of-sight and move

AI in design

Not too smart Don't set expectations too high Game play is more important

Not too dumb Must cover minimum player expectations

Compensate Level design Resource advantages

Action / Adventure

Demo Lange: Splinter Cell: Pandora Tomorrow Ingebrigsten: Grand Theft Auto: San Andreas Pollard: Metal Gear Solid 3 Hahn: Grim Fandango Abero: Prince of Persia: Sands of Time

Non-demo Entin: Myst Reedy: Thief: Deadly Shadows Devlin: The Suffering Rojas: Prince of Persia: Warrior Within Riordan: Grand Theft Auto III