AI Week 5 GAM 224

Outline Announcements Final Project Demos Discussion Break Lecture AI Narrative

Announcements Advising week Game assignments available Readings reorganized a little for the new book

Final Project Game concept document Parts Game overview Mechanics Resources Characters and Story Sample Level

Final Project 2 Team project 3 or 4 members group authorship of overview each 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 characters simulating the opponent simulating other characters In some games it is the whole point classic strategy Sims

Artificial Intelligence Broad field of study 1950s: how to make computers think like people Now how to make computers less stupid

Game AI Uses very little from AI research too slow focused on different problems Main issue "planning" how to get characters to act believably

Planning A planning problem Current state End state Known 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 Example to use machete, must be near player to get near player, move etc. Problem the world changes all the time

Modern planning Much more complex Integration of acting sensing choosing prioritizing etc. Overkill for games

Typical game AI tasks Character behaviors usually scripted actions Route finding many games Resource management in strategy games Modeling character relationships in 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