Accepted Papers

Artificial Intelligence session

Fun in computer games depends on many factors. While some factors like uniqueness and humor can only be measured by human subjects, in a strategical game, the rule system is an important and measurable factor. Classics like chess and GO have a millennia-old story of success, based on clever rule design. They only have a few rules, are relatively easy to understand, but still they have myriads of possibilities. Testing the deepness of a rule-set is very hard, especially for a rule system as complex as in a classic strategic computer game. It is necessary, though, to ensure prolonged gaming fun. In our approach, we use artificial intelligence (AI) to simulate hours of beta-testing the given rules, tweaking the rules to provide more game-playing fun and deepness. To avoid making the AI a mirror of its programmer's gaming preferences, we not only evolved the AI with a genetic algorithm, but also used three fundamentally different AI paradigms to find boring loopholes, inefficient game mechanisms and, last but not least, complex erroneous behavior.

We describe a framework for providing game agents with awareness of the intrinsic spatial qualities of the virtual worlds that they inhabit. We develop a novel data All sessions take place in the Convention Center unless otherwise noted. we will also consider how games themselves can potentially help us reflect on and experiment with our ethics. 4. Game Development: Tools and Techniques Moderator: Peter Brinson. Hotel Figueroa Attend this workshop to talk about cutting edge tools and development methodologies. Discussion topics may include: SCRUM, integrating user testing with game design, and the latest tools being used by the development community. 5. Improvisational Acting Techniques Moderator: Brenda Bakker Harger. Conference Site This workshop will provide participants with an introduction to improvisation and will also encourage participants to seek out continued opportunities to more fully explore the connection between improv and game design. structure based on a modified medial axis, which establishes a mapping between the medial axis and world structures. This data structure can be used to perform queries about the width, curvature and connectivity of a space within a virtual world. Additional information, such as sampled visibility can also be integrated with this framework. An agent-based crowd simulation is adapted to make use of the sensory information provided by this data structure and the success of using this information within two game scenarios is evaluated.

Most game developers think of databases as nothing more than a persistence solution. However, database research is concerned with the wider problem of “declarative processing.” In this paper we demonstrate how declarative processing can be applied to computer games. We introduce the “state-effect” pattern, a design pattern that allows game developers to design parts of their game declaratively. We present SGL, a special scripting language which supports this design pattern and which can be compiled to a declarative language like SQL. We show how database techniques can process this design pattern in a way that improves performance by an order of magnitude or more. Finally, we discuss some design decisions that developers must make in order to adopt this pattern effectively.

Education and Learning

Music is appreciated by people from all walks of life. Music fits into our daily schedules in many ways, from casual listening to cultural events or movies. At a deeper level, the mechanics of music are not usually known to most lay people and learning the components of music theory can be a lengthy and difficult process. We present a new paradigm of social musical exploration and creation system using the physical body as an interface. We have created a physical mixed reality interactive game, which enables people from all walks of life to interact in a physical space and learn fundamentals of music theory through experimentation. The initial prototype teaches pitch, time signature and dynamics in music. Initial player studies were conducted to refine the prototype to improve the usability, playability, and to ensure that the learning objectives are accomplished. We provide an evaluation of the research project and assess the usefulness of the system in the classroom setting as well as an interactive museum setting. Future plans for development are discussed in the conclusion of the paper to provide for the future development direction.

Unlike recreational games, serious games do more than entertain the player. Serious games promote acquisition of information and skills that are valued in both the virtual world and the real world. The challenge is to design and develop serious games that simultaneously create an enjoyable experience for the player as the player develops or improves her skill set as a result of game play and applies these newly developed skills in a real world setting. Because transfer of learning represents the primary goal of serious games, it is crucial that game designers understand the interactions associated with game tasks and their impact on players prior to game development. Borrowing heavily from interaction design, we introduce the user centered game design methodology as the framework for serious game design and apply this technique to the evaluation of the social interactions between Player Characters in a commercial. Massive Multiplayer Online Role Playing Game. Significant results from experimental studies suggest that this genre of games shows great promise as an unorthodox language learning tool for vocabulary acquisition and reveals the importance of social interactions in the virtual space of video games. Finally, we discuss the design implications for serious games that facilitate Second Language Acquisition.

Massively multiplayer online games (MMO) are at the height of interest and growing in popularity in the commercial video game market. New development studios are vying for the position of top MMO, both in the number of users and market value. Recently, interest in online games has entered the realm of educational practitioners and researchers. It was as researchers, as well as game developers and designers in mind, that the USC GamePipe Laboratory has developed its initial version of the academic, open source USC GamePipe Online Game Server (USC GOGS).

In a two-week residential game camp we used the Greenfoot IDE to teach java programming to rising 9th and 10th graders. Students created their own computer games which required learning how to write java programs, create a game design, and create art assets. In this paper we focus on the computer science pedagogy used and describe the initial design of an augmented game development framework for the Greenfoot environment. This framework includes classes for the following useful game elements: Animation, Projectiles, Side Scrolling Worlds, Text Boxes, Clocks and Timers. We describe these classes, discuss the effectiveness of each, and describe potential improvements to their implementation and design. We also report the results of a survey conducted during each of the camps.

Game Design

Moving Parts is a hybrid physical/digital, two-player pinball game designed to elicit different social interactions between players. Using a mixture of consistent and variable rules, the game highlights interdependent and emergent relationships between game rules, social dynamics, and player experience, illustrating some possibilities for social malleability of digital games and presenting some specific pathways through which rules and social relationships affect each other. With the increasing prevalence of digital games that foreground social interaction, it is important to develop methods for understanding and designing such games to more deeply and meaningfully connect to players’ social experiences.

Levels are the space where a player explores the rules and mechanics of a game; as such, good level design is critical to the game design process. While there are many broad design principles, level design is inherently genre-specific due to the wide variety of rules and types of challenge found between genres. Determining genre-specific design principles requires an in-depth analysis of games within the genre. We present such an analysis for the 2D platformer genre, examining level components and structure with a view to better understanding their level design. We then use this analysis to present a model for platformer levels, specifically focusing on areas of challenge. Our framework provides a common vocabulary for these items and provides level designers with a method for thinking about elements of platformers and how to compose them to create interesting and challenging levels.Levels are the space where a player explores the rules and mechanics of a game; as such, good level design is critical to the game design process. While there are many broad design principles, level design is inherently genre-specific due to the wide variety of rules and types of challenge found between genres. Determining genre-specific design principles requires an in-depth analysis of games within the genre. We present such an analysis for the 2D platformer genre, examining level components and structure with a view to better understanding their level design. We then use this analysis to present a model for platformer levels, specifically focusing on areas of challenge. Our framework provides a common vocabulary for these items and provides level designers with a method for thinking about elements of platformers and how to compose them to create interesting and challenging levels.

Learning Through Design

Games are play with conflict. However, players rarely get the chance to explore gameplay besides open conflict. Neutrality in the real world allows actors to avoid conflict and is also used to describe how mediators should act when they negotiate a conflict resolution. Reviewing different definitions of what it means to be neutral this paper investigates how game mechanics that simulate neutrality act as neutral mediators between players. The neutrality of each of the seven game mechanics discussed is related to how impartial they act towards players. This paper concludes that current games have not explored all of the possible neutral mechanics and suggests ways for game developers to incorporate these missing mechanics into games.

There is a growing number of game designers, as well as players, who want games to be about something – games that tackle difficult ideas; that teach us something about ourselves and make us see the world from a different perspective. Last year, Clint Hocking asked in his rant at the Game Developers Conference: “Why isn’t Call of Duty actually about duty? Or why isn’t Medal of Honor actually about honor?” And he goes on to state that the mechanics of TRUST are not more difficult to model than the mechanics of rope, further implying that games emphasize physical concepts such as running, fighting, or climbing over abstract ones, such as DUTY, HONOR, LOYALTY or TRUST.
In pondering Clint’s question, it occurred to us that what makes the mechanics of TRUST more difficult to model than those of ROPE is that they are more difficult to identify in the first place. It is exactly this problem that shall be addressed in the presentation. A systematic approach to identify the elements and dimensions of abstract concepts shall be suggested, drawing heavily on metaphor research.

Navigation, Physical and Spatial

This paper presents a novel approach to modeling a generic cognitive framework in game agents to provide tactical behavior generation as well as strategic decision making in modern multi-agent computer games. The core of our framework consists of two characterization concepts we term as the tactical and strategic personalities, embedded in each game agent. Tactical actions and strategic plans are generated according to the weights defined in their respective personalities. The personalities are constantly improved as the game proceeds by a learning process based on reinforcement learning. Also, the strategies selected at each level of the agents’ command hierarchy affect the personalities and hence the decisions of other agents. The learning system improves performance of the game agents in combat and is decoupled from the action selection mechanism to ensure speed. The variability in tactical behavior and decentralized strategic decision making improves realism and increases entertainment value. Our framework is implemented in a real game scenario as an experiment and shown to outperform various scripted opponent team tactics and strategies, as well as one with a randomly varying strategy.

Procedurally generated 3D worlds pose their own problems in terms of user’s navigation. The rules for supporting wayfinding through specific world generation have to be categorized and implemented in the generative algorithms. Our answer to this problem is based on a combination of the architectural theories by Lynch and Alexander. We adjusted a procedural world generator to include selected patterns as suggested by these theorists. Unlike other research, we put our main focus not on an arrangement of obvious landmarks but instead on the organization of objects that form patterns of much smaller scale in their spatial combination to trace how players structure and comprehend these environmental patterns. Our hypothesis was that these small scale patterns would assist player navigation in procedural worlds. We tested our model in the procedural world generator Charbitat. Statistical analyses showed no significant effect of environmental patterns on player navigation. However, post-experiment questionnaires indicated that users were aware of the patterns and had used them for orientation. This suggests that while patterns were sought after, they alone apparently were not sufficient to improve user navigation in the 3D world.

New Technologies, Tools, and Techniques

Filmmakers, theater directors, and designers take extreme care in aesthetically composing their scenes. This sense of aesthetics is important to promote presence, immersion, and involvement. Video games have adopted many design theories and techniques from linear media, particularly film. However, interactive environments are dynamic and unpredictable, and thus require the development of theories, techniques, and tools specific to their interactive nature. In this paper, we present a lighting design tool that algorithmically adapts lighting to user interaction within game environments at runtime. Previous work includes our work on the Expressive Lighting Engine (ELE), which uses intelligent algorithms to adapt lighting in real-time accounting for variation in context, narrative, and intended artistic effects defined through numerical constraints. We encoded cinematic lighting techniques within ELE as mathematical formulae that guide the system’s choices in terms of lighting to achieve artistic constraints while maintaining visual continuity. The work presented in this paper expands this work in several directions. First, ELE did not take objects’ or scenes’ materials into consideration. This is important since the appearance of objects under lighting conditions depends on their materials. Second, using numerical constraints as a method by which designers encode their artistic intention for lighting proved to be unintuitive. Thus, we present a prototype that builds on ELE and focuses on exploring solutions to resolve these problems.

The use of speech recognition in gaming applications is not entirely new. The growth of voice as a part of gaming has exploded largely due to the popularity of online player matchmaking services such as Xbox Live. Yet, the majority of its use is only limited to communications between players to coordinate game play activities through the use of a headset and a microphone. To further explore the possibilities of using speech recognition to affect game play directly, Motorola has partnered with GamePipe Labs at the University of Southern California. This collaboration aims at leveraging the capabilities of VoiceXML (VXML), and use interactive voice dialogues to directly affect game play on mobile phones. This short paper describes the efforts taken under this initiative, and the results of this collaboration.

The Graphics Processing Units or simply GPUs have evolved into extremely powerful and flexible processors. This flexibility and power have allowed new concepts in general purpose computation to emerge. This paper presents a new architecture for physics engines focusing on the simulation of rigid bodies with some of its methods implemented on the GPU. Sending physics computation to the GPU enables the unloading of the required computations from the CPU, allowing it to process other tasks and optimizations. Another important reason for using the GPU is to allow physics engines to process a higher number of bodies in the simulation. It also presents an automatic process distribution scheme between CPU and GPU. The importance of the automatic distribution for physics simulation arises from the fact that, sometimes, the simu- lated scene characteristics may change during the simulation and by using an automatic distribution scheme the system may obtain the best performance of both processors (CPU and GPU). Also, with an automatic distribution mode, the developer does not have to decide which processor will do the work allowing the system to choose between CPU and GPU. This paper also presents an uncoupled multithread game loop used by the physics engine.

3-D and Cinematography

Game worlds have to be presented to players via some form of visualization to be accessible. Consequently, there is a direct dependency between the virtual game world and this form of presentation. But how does the camera work affect our understanding of the game space? We implemented a dynamic camera system that procedurally switches camera styles depending on the type of region the player is in. We then tested to what degree this camera behavior affects the players’ understanding of the game world and its zoning in comparison with a control group playing the same zoned environment with a default camera. In both cases, recognition of the zones was lower than expected but our results show that after an initial learning phase the recognition was significantly faster when the dynamic camera system was active. Players also appeared to be less “lost” in the game world. The results validate the role of the camera in virtual spaces and suggest a stronger role for visualization strategies in 3D game worlds.

Communicating information to the user is a vital part of the interactive experience. In order to better convey the information to the end user, we must know where to place this information and how to present it in a manner that it will be noticed. Subjectively placing this information is not sufficient since every user will interact with the environment in their own unique manner. Information value is a metric that provides us with the knowledge of which surfaces players looked at most in the environment in the form of an ordered list of surfaces. Using an objective algorithm for discovering the information value of environmental surfaces from recorded player data, we performed a 150 subject information value study and found that placing information in the high value surfaces yields up to 60% improvement in user observation. However, most players did not recall the information that they had seen. We conducted another 150 subject study to investigate what factors improve information retention and found that popular images do improve recall by up to 28%. Finally, we conducted a 30 person study on the effect of changing the player’s task (context) from search to exploration on information recall and found that recall increased by 38%.

We present an approach to generate shots for 3D computer graphics cinematic sequences from event-based descriptions of scenes of conversations between groups of actors. Our approach creates camera setups using a combination of geometric constraints and aesthetic parameters, while ensuring that the resulting cinematic sequence obeys the heuristics of good cinematography. More specifically, our main contributions are the a method for defining hierarchical lines of action and the identification and use of relevant first principles of cinematography for using these lines of actions. Our approach is more flexible and powerful than those proposed in previous work, mainly because it naturally generalizes to any number of actors in a scene.