Adaptive AI Engine for RTS GamesIntroduction to AI Engine & Common Used AI

Techniques

Created by: Abdelrahman Al-OgailUnder Supervision of:Dr. Ibrahim Fathy

Agenda

What’s Game AI? Why AI Engine? Structure of AI Engine Elements That Need AI in RTS Games Areas That Need Improvement in RTS

AI Common Used Techniques in AI

Engine So why working on that project

(what’s new)?

What’s Game AI?

Let the computer think

Goal of Game AI: Entertainment NOT perfection How that guy finds the right answer?

Deeper Blue Example

Why AI Engine

AIEngineAI

Engine

That’s our guy

Structure of AI Engine

Elements That Need AI in RTS Games

Workers (peons, gatherers)

Individual units (soldiers, tanks…)

Town building: how to build my town to max. benefits

Pathfinding What’s the best (not shortest) way to get

from A to B

Elements That Need AI in RTS Games

Low level strategies Which pathfinding algorithm I should

use?

Medium level strategies How to achieve high level strategies?

High level strategies What are my goals?

Elements That Need AI in RTS Games

Terrain Analysis (keep track of your enemy)

Opponent Modeling (know your enemy)

Resource Management (take the control)

Diplomacy Systems (always have allies)

Areas That Need Improvement in RTS AI

Determine when AI element is stuck

Opponent modeling

More strategies less tactics Construct consistent army (solders,

tanks, planes) Think about support lines How to retreat Setup and detect ambushes

Areas That Need Improvement in RTS AI

Learning Some areas of learning:▪ AI opponent get in the same trap repeatedly▪ Know safe map locations and get away from

kill zones▪ Know how human player attacks and which

units he favors▪ Does the player rushes ?▪ Does the player rely on units that require certain

resources?▪ Does he frequently build a number of critical

structures in a poorly defensive place?▪ Are his attacks balanced? ( rock, paper, scissors

example)

Common Used Techniques

Categories of Used Techniques: Decision Making Other Techniques▪ Data-Driven Techniques▪ Perception Techniques▪ Communication Techniques

Decision Making – Finite State Machine

When to use: to represent states

Decision Making – Fuzzy State Machine

When to use: to represent several states at the same time

Decision Making – Genetic Algorithms

Used to find best solutions to a given problems

Genetic Process Rely on the idea of reproduction

Example of using: finding best optimal # of peons working

in each areas (area = building, money, wood, stone…)

Decision Making – Neural Networks

Rely on simulating human brain Used in:

Classification Opponent modeling

Decision Making – Artificial Life

ALife is about searching to find “governing principles” to the life

Newton theorem

Alife Techniques: Cellular Automata Steering Behaviors

Add the creativity to the AI opponent

Decision Making – Steering Behaviors

Simple rules that produces emergent behaviors

Boids research by Craig Reynolds

Used: To simulate real life In producing emergent

behavior Provide autonomies agents

Decision Making – Planning

Planning is, deciding upon a course of action before acting

Usage in games: Pathfinding algorithms Set plans to high level strategies in RTS Games anticipating ambushes

Some of Planning Techniques: A*, Mean & Analysis, Patch Recalculation,

Minimax

Decision Making – Production Systems

As prolog Used techniques:

Forward changing Backward changing

Decision Making – Decision Trees

Complex IF-ELSE Statements represented as tree

Usage if games: Player modeling High level strategies

Other Techniques – Data Driven AI

Scripting Systems

Using an external resource (not coded) that controls the AI opponent

Advantage Add extendibility to the game

Other Techniques - Messaging

Supplies communication between game objects

Other Techniques – LBI Systems

LBI: Location Based Information Systems

It’s a perception technique

Keeps track of the world attributes

Common techniques: Influence Maps Terrain Analysis Smart Terrain

Other Techniques – LBI Systems

Usage in games: Helps with obstacle avoidance Detecting player, resources places Danger specification (keep track of kill

zones) Discover critical points in the world (as

bridges)

What’s new?

Future of wars is going to be more robotic Sharing & validating plans

MIT asks for researches in this area (10-2008)

Alex J.C. said: “there’s no real learning and adaptation in commercial games”

Researches in this area is so active! One of the papers date 6-2008