Kevin McGee

NetEffect: a network architecture for large-scale multi-user virtual worlds

We describe NetEffect, a highly-scalable architecture for developing, supporting and managing large, media-rich, 3D virtual worlds used by several thousand geographically dispersed users using low-end computers (PCs) and modems. NetEffect partitions a whole virtual world into communities, allocates these communities among a set of servers, and migrates clients from one server to another as clients move through the communities. It devotes special attention to minimizing the network traffic, in particular, the traftic that must go through servers. HistoryCity, a virtual world for children, has been developed on NetEffect and is currently being beta-tested for deployment in Singapore.

Developing social virtual worlds using NetEffect

This paper describes NetEffect, an infrastructure for developing, supporting, and managing large, media-rich, 3-D social virtual worlds for use by several thousand geographically-dispersed users using low-end computers (PCs) and modems. It has been modularized into six components, in the form of a toolkit, which simplifies the development of network-based virtual worlds. NetEffect partitions a whole virtual world into communities, allocates these communities among a set of servers, and migrates clients from one server to another as clients move through the communities. It devotes special attention to minimizing the network traffic, particularly the traffic that must go through servers. HistoryCity, a virtual world for children, has been developed on NetEffect, which is being beta-tested for deployment in Singapore.

AI for dynamic team-mate adaptation in games

There is a long tradition of developing games in which the difficulty level is dynamically adapted to the performance of human players. However, there has been less work on the creation of game systems that perform dynamic team-mate adaption - and even less on developing team-mate NPCs (Non Player Characters) that adaptively support players in the face of opponents that adaptively increase the difficulty for the player. This paper is based on preliminary research to identify the key elements involved in developing “buddy” NPC team-mates that dynamically adapt to the needs and behaviors of human players while cooperating to compete against adaptive AI opponents. We discuss the computational and design challenges involved in developing such agents in the context of a simple test game called Capture the Gunner (CTG). The main contributions of the paper include: a proposed vocabulary and framework for understanding/modeling team-mate systems with adaptive difficulty, a particular technique for adaptive team-mate cooperation in the face of an adaptive opponent, and the identification of several significant new issues that arise in the process of developing computer games that involve adaptive NPC team-mates that cooperate with the player in the face of adaptive opponents.

Are artificial team-mates scapegoats in computer games

In cooperative games that involve team-mates that are controlled by either a computer or another human player, is there a difference in how humans assign credit or blame? There has been some related work on computers as team-mates and credit/blame assignment, but there does not seem to have been work to show whether the belief that a team-mate is human or not affects this. A qualitative study was conducted, in which 16 participants played variations of a team-based game with one of four kinds of team-mates: human (real or perceived) or AI (real or perceived). The two main findings of this research are that the perception of whether a team-mate is human or computer results in different credit/blame assignment and results in inaccurate skill assessment.

Frown more, talk more: effects of facial expressions in establishing conversational rapport with virtual agents

How can conversational agents be better designed to build rapport with human beings? Related work on creating rapport through conversational agents has largely focused on nonverbal contingent envelope feedback. There is relatively little known about how forms of emotional feedback play a role in building rapport between agents and humans. This paper describes a study in which people told stories to an agent that provided emotional feedback in the form of facial expressions. Rapport was measured through the length of the stories, the fluency of their speech, and the users own subjective experience. Surprisingly, results indicated that inappropriate emotional feedback increased story length, which was the opposite of previous studies on envelope feedback that had shorter stories in unresponsive conditions. This paper explains the factors particular to emotional feedback that could cause this difference.

Designing hypertext tools to facilitate authoring multiple points-of-view stories

How can authoring tools help authors create complex, innovative hypertext narrative structures? Tools for creating hypertext fiction typically represent such narratives in the form of nodes and links. However, existing tools are not particularly helpful when an author wants to create a story with a more complex structure, such as a story told from multiple points of view. In this paper, we describe our work to develop HypeDyn, a new hypertext authoring tool that provides alternative representations designed to make it easier to create complex hypertext story structures. As an initial exploration, the tool has been designed to support authoring of interactive, multiple-points-of-view stories. In order to describe the tool, we describe a simplified transformation of Rashomon into a progressively more interactive narrative. Along the way, we identify useful new representations, mechanisms, and visualizations for helping the author. We conclude with some thoughts about the design of interactive storytelling authoring tools in general.

Automated Generation of Geometry Questions for High School Mathematics

We describe a framework that combines a combinatorial approach, pattern matching and automated deduction to generate and solve geometry problems for high school mathematics. Such a system would help teachers to quickly generate large numbers of questions on a geometry topic. Students can explore and revise specific topics covered in classes and textbooks based on generated questions. The system can act as a personalized instructor - it can generate problems that meet users specific weaknesses. This system may also help standardize tests such as GMAT and SAT. Our novel methodology uses (i) a combinatorial approach for generating geometric figures (ii) a pattern matching approach for generating questions and (iii) automated deduction to generate new questions and solutions. By combining these methods, we are able to generate questions involving finding or proving relationships between geometric objects based on a specification of the geometry objects, concepts and theorems to be covered by the questions. Experimental results show that a large number of questions can be generated in a short time. We have tested our generated questions on an existing geometry question solving software JGEX, verifying the validity of the generated questions.

What we have here is a failure of companionship: communication in goal-oriented team-mate games

There is a fairly common assumption about real-time, goal oriented, multiplayer games: communication is primarily appreciated (and used) for more effectively attaining goals. But an interesting question that does not seem to have been explored in the literature is whether the desire for companionship is a significant factor in peoples desire for and use of communication channels in real-time, goal-oriented, cooperative games. A qualitative study was conducted in which 40 participants played variations of a real-time, goal-oriented, cooperative game with either human or artificial (AI) team-mates, using different communication modalities. Participants consistently expressed a strong desire for the ability to communicate with a team-mate, arguing that it made gameplay more effective and more enjoyable. The significant finding of this study is that in some cases, the strong desire for (and use of) communication channels in realtime, goal-oriented, cooperative games seems to actually be more of a desire for (and experience of) social companionship.

Rereading in interactive stories: constraints on agency and procedural variation

A central problem for interactive storytelling research is how to create a story which procedurally varies as the result of a users actions, while still feeling like a story. Research has largely concentrated on how to provide coherent variations each time a user experiences an interactive story, without consideration for the relationship between subsequent experiences. This paper examines the issues that arise when designing an interactive story system which is intended to be reread as the result of a reframing. Through a discussion of several types of reframing drawn from non-interactive films, we argue that, when an interactive story makes use of a reframing to encourage rereading, the requirements for narrative coherence, selection and ordering extend across reading sessions. This introduces constraints in terms of what can be varied procedurally in response to user actions which do not occur in interactive stories which are not explicitly designed to be reread.

Designing Storytelling Games That Encourage Narrative Play

Storytelling games are a form of competitive storytelling framed in the context of gameplay. However, most existing storytelling games emphasize competitive gameplay and winning at the expense of competitive narrative play; they tend to be storytelling games rather than storytelling games. This paper explores issues related to the design of storytelling games that are won through narrative play and proposes a number of design rules for this. These design rules not only help in the design of storytelling games with a stronger element of narrative play, they also have implications for the design of computational storytelling systems.