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Tutorial onMultiAgent Virtual Worlds Dr. Fuhua Lin

International Graduate Research Workshop 2013on Adaptivity and Personalization in Informatics, March 2324, 2013 Edmonton, Alberta, Canada

Or Intelligent Virtual environment1OutlineIntroduction Related WorkThe Roles of Agents Architectural DesignQuizMASterConclusions and Future work The technological advancement has revolutionized the virtual world genre of the Internet online community that provides computer-simulated intelligent virtual 3D environments whereby users can interact with one another and use 3D objects embedded in that environment. Virtual environments can provide more dimensions than physical environments and more social ways for people to learn from one another as they face complex challenges. In this talk I will present an ongoing project by my team that builds engaging, affectionate, and effective sociable pedagogical agents in 3D virtual worlds for new social learning. Utilizing the theory of Transformed Social Interaction (TSI), we design sociable pedagogical agents with abilities of self-representation, sensory abilities, emotional states reasoning, and situational awareness. A prototype of virtual quiz show, QuizMASter, has been implemented in Open Wonderland to realize the abilities, and will be used to test for the effectiveness of the approach.2Goal of this TutorialDiscuss the basic concepts on constructing virtual worlds with multiagent systems (MAS).Virtual WorldsVirtual Worlds are 3D graphical environments that provides more engaging and more immersive user experiencecan provide more dimensions than physical environments more socialnuanced ways (in ways which are able to show slight difference that may be difficult to notice but are fairly important ) for people.

Athabasca Universitys Academic Research Centre in Second LifeAU's new ARC building was exactly replicated on the AU island to assist with furniture placement and other occupancy decisions. A video of this building is accessible here: http://www.youtube.com/watch?v=pganB4_F7AQ

There are avatar only in this demo!The avatars are 3D characters controlled by the participants.

Multiagent SystemsMAS --- encompasses distributed problem-solving applications, such as network management, which do not typically involve Virtual Worldshas a focus on inter-agent Communication. Coordination and Negotiation.COMP667 (Multiagent Systems) of Athabasca University

Group Decision MakingThere are many settings where a potentially large number of agents, each with its own goals and objectives, collectively interact so as to produce a solution to some problem.A solution that is produced under these circumstances often reflects the tug-of-war that led to it, with each agent trying to pull the solution in a direction that is favorable to it.

Game TheoryThe field of game theory provides a natural framework in which to talk about what happens in such situations, when a collection of agents interacts strategically --- in other words, with each trying to optimize an individual objective function.

AvatarsNPCsSoftware agent 1

Software agent 2

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Software agent 7

Software agent 8

Autonomous Agents

Russell and Norvig, Autonomous Agents in Virtual WorldsUsing virtual worlds as a technique for exploring agent behavior and agent believability, or Using agents as a way of extending virtual worlds into new application areas, includingSynthetic agents: intelligent actors (Hayes-Roth et al. 1996), virtual actors, virtual humans, (e.g. NPCs) Avatars (which are physical representation of human users) In a 3D multi-user Web environments.

Synthetic agents: Such automated agents are able to portray fictive characters having a given personality, and to interact withusers in a multimedia environment in well-defined stories or in improvisational contexts.

Hayes-Roth, B.; van Gent, R.; Huber, D. 1996. Acting in Character. To appear in R. Trappl and P. Petta (Eds.), Creating Personalities for Synthetic Actors. TechnicalReport KSL-96-13, Knowledge Systems Laboratory, Stanford University. 11AGENTSExist in an environment which they need to perceiveAutonomously react to changes in that environmentProactively act to achieve goalsInteract with other agentsBehavior can be emergent (often coded in a declarative language)Belief-Desire-Intention (BDI) models a subset of the human mindWhy Autonomous?

The more autonomous, the more convincing to the user and sustains the feeling of presence in a virtual world! Behavior Modeling:Agents Level of Autonomy (LOA)Degree of autonomy of virtual environments depends on the autonomy of their components, three level of autonomy (LOA) (Thalmann, 2000):Guided: user-guided, like avatar.Programmed: could use omniscient approach, but inefficient.Autonomous: Have perception limitationPrediction about the world are always fallible The potential for reuse of agents in different virtual worlds The ability to distribute individual agents over separate processorsIs Autonomy useful and appropriate for agents in virtual worlds?Omniscient agent management soon runs into combinatorial problems when it must track of what each agent is supported to know and perceive.

NPCsRealistic non-player characters (NPCs) are essential to making virtual environments more real for players. This is true in video games where more believable NPCs support the story narrative of a game, making them more immersive, more convincing. It is also true in other areas where virtual worlds are used such as education, increasing the effectiveness of those environments.

PROBLEMNon-player Character (NPC) behaviors in 3D virtual worlds are not sophisticated enoughImpacts believability and ability to create complex scenariosDomainsVideo gamesEducation/Training virtual environmentsSOLUTIONImproved Artificial Intelligence driving NPC behaviorMachine LearningNatural Language ProcessingMachine Perception (watching the user)Multi-agent Systems (MAS)POSSIBLE APPROACHESTwo approaches to combining an MAS with a game engineA fully custom integrated solutionA modular solution, integrating existing componentsGamebotsA fully custom integrated solution

Virtual Singapora

Problem in using MAS in Virtual Worlds Game AI is usually closely coupled with other parts of the game code which makes it hard to reuse or replace. Requires a large amount of investment in time and resources and a high level of expertise in Agent Oriented Software Engineering (AOSE).

GOAL Create an integrated framework to simplify the process of creating agents to control NPCs in Open WonderlandAnimationMovementEnvironmental perceptsSynchronizationPAST RESEARCHGamebots/Pogamut (2002 - GameBots: A Flexible Test Bed for Multiagent Team Research)Commercial server (Unreal Engine)Open source client (using Unreal scripting language as API)Other ProjectsNot Java-based (C, C#) or not open sourceOpenSim (C#) supports Second Life protocolAgents RolesResearch that has been done with virtual agents and multi-agent systems can be leveraged to create more realistic NPCs and purposeful communication channels among agents for applications like game-style educational activities. Agent-controlled-NPC Human Users Avatar

Our ApproachControlling NPCs with intelligent agents through the creation of an interface between a multi-agent system to a virtual world engine.

Open Wonderland

Open Wonderland is a toolkit for building 3D virtual worlds (Kaplan, J., & Yankelovich, 2011). The architecture of the system, based entirely on open standards, is highly modular and designed with a focus on extensibility.

Kaplan, J., & Yankelovich, N.: Open Wonderland: An Extensible Virtual World Architecture. ;IEEE Internet Computing(2011), 38-45

Underlying Technologies JasonA platform for the development of multi-agent systems Java-based open-source MAS used for creating BDI agents that are based on the model of belief, desires, intentions. A Java-based interpreter for an extended version of AgentSpeak. The core code is easily extendible making it easy to add customizations at the agent and environment level. AgentSpeak, a Prolog derivative that is well suited to programming in AI, is the language used to control agents.AgentSpeak is only language that will be supported, at least initially, when it comes to agent scripts run to control NPCs in Open Wonderland. Declarative style --- offers a different way to script NPC behavior than the more functional methods already available in Open Wonderland (like JavaScript).

Underlying Technologies JADE Container model Agent Management System (AMS) Directory Facilitator (DF) to facilitate the management of agents. CArtAGo (Common ARTifact infrastructure for AGents Open environments) Agents & Artifacts (A&A) model, using workspaces, agents, and artifacts (exposed resources).

MEMORYPerception

A Client with TextChat Echo Agent Proximity Detection/* Initial goals */!listen.@msgHandler[atomic]+proximity(FromUser,Enter,Distance) : proximity(_,_,_)[source(percept)]