Of Stick Figures and Boxes

OR

Off the Shelf tools For Communicating your Game Design

Montreal International Game Summit, 2006

James Everettjames.everett@a2m.com

James Everett

Game Designer

Game Designer

Artificial Mind and Movement

Communication

Design =

Programming =

Art =

Designer’s Vision

Designer’s Vision

Programmer’s Implementation

DesiredGame

Oh Joy! Oh Rapture!

Designer’s Vision

Programmer’s Implementation

DesiredGame

Designer

Programmer

DesiredGame

Not aDoctor

What is the Unified Modeling Language?

History of UML in 30 Seconds or Less

???

OMG!(Object Modeling Group)

1997

2004

1.0

2.0

How does UML work?

English

FrançaisEspañol

Deutsch

NihongoBosanski

Dansk

Esperanto

but not cleverComputers: fast,

if (Game) !=

then

PPPPPP

• Prior

• Planning

• Prevents

• Piss

• Poor

• Performance

Stand

Jump

Fall

StandAvatar waits in idle stand state-Player can jump from stand

JumpAvatar jumps into the air-After completing Jump the avatar enters the fall state.

FallAvatar is airborne and cannot jump again-When the avatar reaches the ground return to stand

UML Text

Player Avatar

Behavior Diagrams?

Use Case Diagram State Machine Diagram Activity Diagram

Use Case

Actor

Stand

Jump

Fall

Punch Enemy

Reduce Enemy HP

Enemy EntersHurt State

Use Case Diagrams

Use Case

Actor

Actor

Customer

ATM

Withdraw

Deposit

BalanceCheck

BankDatabase

Avatar

GAME

Movement

Combat

Health

Enemy

Actor Player/avatar NPC/Enemy

= and

Punch

Avatar

ACTORGAME

ASSOCIATION

Use Case

Actor

Use Case

1) Use Case specifications2) Provide a detailed explanation of use cases3) Through text

Use Cases arePlayer Centric

Punch

Avatar

Punch: 1) The avatar punches an enemy and causes damage. 2)...

Kick: 1)...

Shoot: 1)...

Use Case: Combat

Kick

Shoot

1) The avatar punches an enemy and causes damage.

What is an enemy?How can I tell if I hit the enemy?What if I don’t hit the enemy?How much damage do I cause?

1) The avatar punches an enemy and causes damage.

Enemy = Actor

Damage = State

Notes on Enemy

• Enemy is a non-player character

• Enemy will attack the player

• The Player must defeat the enemy

• The player defeats the enemy by reducing its hitpoints to 0

• To reduce the enemy’s hitpoints the player must successfully attack the enemy

Player Combat State Machine Diagram

(rev 0.01)

Punch

Idle

[Player presses Punch]

[Punch Complete]

Player Combat State Machine Diagram

(rev 0.01)

Punch

Idle

[Player presses Punch]

[Punch Complete]

State

Transition

Guard Condition

Punch Enemy

Reduce Enemy HP

Enemy EntersHurt State

Player Combat Activity Diagram (rev 0.01)

Punch Enemy

Reduce Enemy HP

Enemy EntersHurt State

Initial Node

Punch Enemy

Reduce Enemy HP

Enemy EntersHurt State

Initial Node

Flow

Punch Enemy

Reduce Enemy HP

Enemy EntersHurt State

Initial Node

Flow

Activity

Punch Enemy

Reduce Enemy HP

Enemy EntersHurt State

Initial Node

Flow

Fork

Activity

Punch Enemy

Reduce Enemy HP

Enemy EntersHurt State

Initial Node

Flow

Fork

Activity

Parallel Activities

Punch Enemy

Reduce Enemy HP

Enemy EntersHurt State

Initial Node

Flow

Fork

Activity

Join

Parallel Activities

Punch Enemy

Reduce Enemy HP

Enemy EntersHurt State

Initial Node

Flow

Fork

Activity

Parallel Activities

Join

Activity final node

Player Combat Activity Diagram (rev 0.01)

Punch

Player

Punch: 1) The player punches an enemy and causes damage. 2) Punching an enemy causes it to enter a Hurt state 3)...

Kick: 1)...

Shoot: 1)...

Use Case: Combat

Kick

Shoot

Hurt state

Punch Enemy

Reduce Enemy HP

Enemy EntersHurt State

Punch

Idle

[Player presses Punch]

[Punch Complete]

Punch

Avatar

Kick

Shoot

Kim Possible: Player Combat Actions Use Case Diagram

Kim Possible Jump State Machine Diagram

Is Enemy HP 0?

Punch Enemy

Reduce Enemy HP

Enemy EntersHurt State

No

Kill EnemyYes

More UML Notation

Decision

Note

<<extends>>Timer

Exception

Use Case

Activity

GeneratingSignal

ReceivingSignal

Where does it fit?

Concept

Designer

Programmer

Game

Designer

Programmer

WARNIN

G

Use Case

• All forms of documents must be maintained

• Impractical to create state machines and activity diagrams for everything

WARNIN

G

Don’t be afraid to throw it away

WARNIN

G

Complex AI may not play well with UML

WARNIN

G

•Removes confusion!•Clarifies Designs!•Scrubs high level to low level!

Still not aDoctor

Resources• Books

– UML Demystified– Elements of UML 2.0 Style– UML Distilled

• Programs– StarUML (free, open source)– Visual Paradigm

• Watch out for ATM examples• www.agilemodeling.com

Contact: james.everett@a2m.com