reading course - realistic psychosocial behaviour in non player characters

7/28/2019 Reading Course - Realistic Psychosocial Behaviour in Non Player Characters

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Realistic Psychosocial Behaviour

in Non Player Characters

Reading Course by Christine Bailey


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Overview NPC psychology

Typical NPC control architectures Social Science

Relevant social computing research


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NPC Psychology Cognition

Thinking

Emotion

The sum of past events

Many many different models possible

Categorical vs. dimensional


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Typical NPC Control Actors vs. Agents

The usual suspectsactor control

General agent architectures

Specialized agent architectures


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Actors or Agents? Actors

Not autonomous

Actions are scripted/hard-coded Actors are directed

Agents

Autonomous

Not hardcoded Not rigidly directed

Some NPCs can be both via switching


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NPC Control in Games - Actors Usually:

FSMs (i.e. for state of mind)

Scripting for behaviour

All states and transitions must be defined a

priori


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Agent Architectures Reactive/Reflex

Triggering

Internal stateself-awareness & memory

Goal-based

Preferred states

Goal importance: First-come, first-served

Also, no plan preference

Utility-based

Utility-value on goals, plans

Anytime


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Agent Architectures All of these have cognition

Only utility-based has emotion (non-

arbitrary plan-selection)


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Emotion as decision-making According to Damasios studies of people

with brain damage:

If cognition and emotion are separated,

decision-making cannot occur in a non-

arbitrary fashion

Cognition=plan-generation Emotion=plan-selection (non-arbitrary)


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Specialized Agent Architectures Soar

H-CogAff

EXCALIBUR

being-in-the-world


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Soar Utility-based

Some components:

Learning, knowledge, goals

Preference list

So, this is an architecture that considersemotion


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H-CogAff Anytime-based

Several layers:

Reactive (quick responses)

Deliberative (goal-based)

Meta-management (learning)

Also: Personality module


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EXCALIBUR Anytime-based

Concerns:

Incomplete knowledge planning

Resource needs

Temporal scheduling


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being-in-the-world Hybrid architecture

Real-time coping

Perception & Reaction

Knowledge base

Plans -> actions

Reasoning

Plan generation


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Specialized Agent Architectures One of the architectures has emotion (Soar)

One even has personality (HCogAff)

But none of these architectures really

consider social systems


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Social Science NPCs should consider social stimuli as

well as physical stimuli when making

decisions


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An overview of the social stuff Attitudes:

Faking it with reputation systems

Remembered interaction histories

Change of attitude

Group influences:

The flow of opinion


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An overview of the social stuff Social roles, world view, etc.:

A high level architecture for believable social

agents

An attempt to integrate mood, personality,

& social networks:

Realistic Reaction System


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Gimme some attitude Faking it with reputation systems

Remembered interaction histories

Change of attitude


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Reputation Systems i.e.Fable, Thief: Deadly Shadows, Ultima

Online,

NPC opinions of player

No opinions about other NPCs

No individual opinions (sometimes groups) Immediate and global


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Reputation Systems Note that this is only faking a social

system


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Remembered Interaction

Histories Tomlinson & Blumberg (2002)

Every new interaction with a stimulus

changes the way we feel about that

stimulus

So says Damasios Somatic Marker

Hypothesis


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Histories Key elements

Current emotional state

Current object of interest

Emotional memory (per object)


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Histories Each new interaction, current emotional

state changes:

NPCs current emotional state

Remembered emotional memory

On interaction end, remembered emotional

history is updated:

Factor in the emotional state during

interaction


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Attitude Change Prendinger & Ishizuka (2002)

Attitude: a disposition to like/dislike

something (or someone, or some place, )


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Attitude Change Attitude affected by:

Previous attitude

Weight of emotional events

Recency of emotional events

Current events


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Events that conflict with previous

attitude? Momentary vs. Essential like/dislike

Momentaryevent is integrated with

previous attitude

Essentialevent replaces previous attitude


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The influence of the group Opinion flow

Peoples opinions are not static they may

change depending on new events, peer

opinions, etc.


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Opinion flow as flock Cole (2006)

Combines:

Social Network Analysis

Boids algorithm


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Social Network Analysis (SNA) Nodes

Ties

Hubs

Nodes w/ high number of ties


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Attack of the Boids The Boids algorithm

Alignment (steer towards avg. heading)

Cohesion (move to avg. position)

Separation (avoid crowding)

Field of vision


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Opinion flow as a flock Alignmentsteer opinion towards avg.

group opinion

Cohesionsteer opinion towards avg.

opinion of people of respect

Separationsteer opinion away from avg.

opinion of people of contempt

Field of visiontie connectivity score


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Cool, dynamic changes of

opinion In real life, people groups change their

opinions

i.e. groupthink, conformity,

Most simulated environments: everyone

has static opinions/beliefs


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Social roles, world view, etc. A high level architecture for believable

social agents

Social roles, social roles, social roles!


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A high level architecture for

believable social agents Guye-Vuilleme & Thalmann (2001)

Social roles:

A coherent set of standard behaviours (plans)

Multiple exist in single individual

Are a way of adapting to a situation

Can inherit from other social roles (i.e. woman,

mother)

Are associated with other social roles (i.e. mother,

father)


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believable social agents Role switching through activation energy

Role activation energy associated with:

Initial role weight

Locations

Times

Locality to associated roles (i.e.mother/father)

Role energy can also be inhibited


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believable social agents Values

pursuit of an ideal abstract state (because I

am honest.) A classifying criteria (because hes a

crook.)

Action-selection based on being right, not

being successful

World viewvia own interests, integratedvalues, norm-based behaviour


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believable social agents Cognitive module

Active role?

Belief generation

Social reasoner

selects behaviour by weighing beliefs/values

Type identifiers

Inference engine, world view


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Integrating psychology and social

networks The Realistic Reaction System


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The Realistic Reaction System

(RRS) Gruenwoldt, Katchabaw, & Danton (2005)

Integration of:

Personality

Mood

Social relationships


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The RRS Elements:

AI Controller

Personality/Mood Filter

Relationship Network

Relationship Manager


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The RRS Social ties have:

Type

History

Regularity

Strength

Polarity


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Summary NPC Psychology

Cognition & Emotions

NPC control Actors, Agents,

Social Science

Relevant social computing research Attitudes, group influences, social roles, world view,

etc., integrating mood, personality, & social networks


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The End Questions?

reading course - realistic psychosocial behaviour in non player characters

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