Research Directions in Computer Game AI Rafael Cabredo
Your speaker Rafael Cabredo Faculty at De La Salle University Research interests: AI in Computer Games Graphics Game Development Contact info: cabredor@dlsu.edu.ph
What will I talk about? Artificial Intelligence in Computer Games
Key questions Why study computer games? Why study AI in games? What kind of research is involved? What has been done in this area? Local research International research
The Computer Game Industry But first, How many of you play computer games during your free time?
The Computer Game Industry 1 st games (~50 years ago) 10 years later 2000 Pong from Atari (2 players) Pacman AI for Ghosts Motion capture High level design 3D animation Large-scale terrain MMOG
Some facts 50% of all Americans age 6 and older play computer and video games The average age of a game player is 29 years 92% of all games are purchased by adults 43% of game players are women 60% of frequent gamers play with friends
Some facts There will be 131M online gamers worldwide in 2006 (DFC Intelligence Report)
Impact on Economy Total Gamers = 430M in 2003 (1/4 are online) Over US$ 20B compared to US$ 70B in movie industry EA, 4 th largest software company in 2003 In the Asia Pacific region, online gaming has contributed US$ 533M to video game business in 2002
Impact on Economy The releases of Doom 3 and Half-life 2 may be responsible for more computer upgrades than any other factor Article in inq7.net by Oliva, Erwin Online Gaming boosts hardware sales in RP
Philippine Game Industry According to IDC: US$2.8 million subscription revenue in 2003 from nearly zero in 2002 CAGR 2002-2007 of 58.4% in online gaming subscription Internet café factor
Philippine Game Industry According to IDC: viable broadband options and attractive price pre-paid cards still preferred (no viable alternatives) MMORPG continues to dominate
Philippine Game Industry In 2000, game related companies were mostly game publishers ex. Level-up!, Mobius First Filipino game development company that published a PC game: Anino Entertainment
Philippine Game Industry Currently around 14 game dev companies Anino entertainment Anino Mobile Azalea Blitsoft, Ltd. Cube Interactive esoft Interactive Flipside Games Gametel Laro Corporation Ladyluck Digital Media Inc. Matahari Studios Secret Six Slycesoft Games Development Company ViTAS Development
Summary There is a market for games in the country (mobile / online games) The Philippines has started to gain interest in game development Game industry = BIG money
What makes games sell? Currently selling point of games: 1. Game Design a. Interactive & Dynamic b. New kinds of design/games c. Replayability
What makes games sell? Currently selling point of games: 2. Graphics a. Humans are visual b. Full 3D c. Realism in the virtual world (physics) d. Non-photorealism / new art styles
What about AI? Not a priority in game development Difficult to market
Recent developments Jason Rubin observed (GDC-Europe, 2003): Graphical improvement is slowing down. The consumer is less aware of differences. We have passed the threshold and graphics is no longer a primary selling point for games.
Recent developments Technology has developed faster processors, and dedicated hardware for graphics and physics Processor can be used for handling AI computations Pathfinding chip is being designed
AI in Games
What kind of games? Not the Classic games 8-Puzzle problem Chess 圍 棋 (wéiqí) / Go / 囲 碁 (Kanji)
What kind of games? Perfect Information Imperfect Information Deterministic Chess, Checkers, Go, Othello Games of the General Chance Backgammon, Monopoly Pusoy Dos, Poker, Scrabble
What kind of games? real games Environment characteristics: Imperfect information Dynamic Interactive Non deterministic (persistent)
Areas of Research Intelligent opponents Intelligent teammates & units (the stupid wingman problem) Guiding behavior of NPCs Steering Pathfinding Scripting Final State Machines
Steering / Navigation Movement to an easy to reach target location Use vectors Applications: Individual behaviors Obstacle Avoidance Wall / Path / Flow field following Coordinated group movement: Flocking (Birds/fish) Queuing (at a doorway or fork) Leader following
Pathfinding Uses waypoints to help NPCs find a route Most used algorithm: A* Software Demonstration
Finite State Machine FSMs describe under which events or conditions a current state is to be replaced by another ex., switching from attack to escape mode
Finite State Machine
Finite State Machine From Quake
Finite State Machine FSM incorporating the use of probability theory for modeling decision-making under uncertainty. Approach: Bayesian Networks
Other Areas of Research Voice recognition Must accept all sorts of people, without any training. Computer-generated speech Must not only handle inflections but also create a sense of the character and personality of the speaker. Recorded snippets can only go so far.
Areas of Research Natural language comprehension and generation Automated storytelling (the AI dungeon master)
Façade (Mateas, 2005)
Drama = character + plot Characters Personality Emotion Self motivation Change Social relationships Consistency Illusion of life Tension/Complexity Plot structure Exposition Crisis Rising action Inciting incident Climax Time Falling action Denouement
Game-Specific Approaches Sport Games AI in games / NPCs should not have optimal solutions. Instead they should maximize the players fun AI is also used in camera control and commentator script FIFA 2005
Game-Specific Approaches Strategy Games It s ok to cheat as long as it increases player s fun (makes the game more challenging) Lord of the Rings: Battle for Middle Earth
Game-Specific Approaches Racing Games Not about realism but fun for the player More on steering Allow a car to be infront of the player just to add more challenge Has more realistic physics
Related Research @ DLSU-CCS Intelligent opponents CAN: Case Based Reasoning in an Adversarial Non-Player Character MAHUSAI: Using a Supervised Learning Algorithm in a Real-Time Strategy Game RL Hero: A Reinforcement Learning Hero in a Real-Time Strategy Game
Related Research @ DLSU-CCS User Support UMAGA: User Modeling to Assist in a Game
Agimat Uses Stratagus and Wargus open source An RTS game environment Uses LUA scripting for unit behavior
CAN
MAHUSAI Training of MAHUSAI
RL Hero RL Hero: Kapre
Demo of RL Hero Run demo
UMAGA Predicts behavior of user and assists during the game
Games in Education VocaVentures (2003)
Other related research Development of Game development Tools 2D Integrated Development Environment for Mobile Games 3D Game API for Mobile Games
Take home points 1. Game Development is HERE a. A lot of focus on mobile games b. Growing interest in PC / console based development 2. There are a lot of research opportunities 3. The Filipino talent and ingenuity can help develop the economy
Resources Adams, E. (2005) Emerging Issues in Game Design. Future Play 2005 Mateas, M. (2005) AI is the future of gaming. Future Play 2005 Nareyek, Alexander. Artificial Intelligence and Computer Games- State of the Art and Challenges. Lecture at Center for Engineering and Sustainable Development Research, Waldo Perfecto Seminar Room, De La Salle University. October 19, 2004 Nareyek, Alexander (2004). AI in Computer Games. QFocus: Game Development. pp.59-65 [online] Available: http://www.aicenter.com/publications/nareyek-acmqueue04.pdf
Links to AI in Games Artificial Intelligence Interface Standards Workshop of the International Game Developers Association (http://www.igda.org/ai/) Steven Woodcock s Game AI Resources (http://www.gameai.com) Game AI Articles and Research (http://www.aiwisdom.com) Arnit Patel s Game Programming and A* information (http://www-csstudents.stanford.edu/~amitp/gameprog.html#paths)
Links to AI in Games Craig Reynold s Resources on Steering (http://www.red3d.com/cwr/steer) The EXCALIBUR Project (goal-directed action planning) (http://www.ai-center.com/projects/excalibur/) Computer Games Boon or Bane for AI Research? (an article about whether AI research makes relevant contributions) (http://www.ai- center.com/references/nareyek-04- gameairesearch.html)
Research Directions in Computer Game AI Rafael Cabredo