International Journal of Computer Games Technology http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2014 , Hindawi Publishing Corporation . All rights reserved. Neural Network to Solve Concave Games Mon, 10 Mar 2014 13:09:28 +0000 http://www.hindawi.com/journals/ijcgt/2014/249721/ The issue on neural network method to solve concave games is concerned. Combined with variational inequality, Ky Fan inequality, and projection equation, concave games are transformed into a neural network model. On the basis of the Lyapunov stable theory, some stability results are also given. Finally, two classic games’ simulation results are given to illustrate the theoretical results. Zixin Liu and Nengfa Wang Copyright © 2014 Zixin Liu and Nengfa Wang. All rights reserved. Analytical Ballistic Trajectories with Approximately Linear Drag Thu, 30 Jan 2014 09:44:39 +0000 http://www.hindawi.com/journals/ijcgt/2014/463489/ This paper introduces a practical analytical approximation of projectile trajectories in 2D and 3D roughly based on a linear drag model and explores a variety of different planning algorithms for these trajectories. Although the trajectories are only approximate, they still capture many of the characteristics of a real projectile in free fall under the influence of an invariant wind, gravitational pull, and terminal velocity, while the required math for these trajectories and planners is still simple enough to efficiently run on almost all modern hardware devices. Together, these properties make the proposed approach particularly useful for real-time applications where accuracy and performance need to be carefully balanced, such as in computer games. Giliam J. P. de Carpentier Copyright © 2014 Giliam J. P. de Carpentier. All rights reserved. Analyzing the Effect of TCP and Server Population on Massively Multiplayer Games Mon, 20 Jan 2014 06:42:53 +0000 http://www.hindawi.com/journals/ijcgt/2014/602403/ Many Massively Multiplayer Online Role-Playing Games (MMORPGs) use TCP flows for communication between the server and the game clients. The utilization of TCP, which was not initially designed for (soft) real-time services, has many implications for the competing traffic flows. In this paper we present a series of studies which explore the competition between MMORPG and other traffic flows. For that aim, we first extend a source-based traffic model, based on player’s activities during the day, to also incorporate the impact of the number of players sharing a server (server population) on network traffic. Based on real traffic traces, we statistically model the influence of the variation of the server’s player population on the network traffic, depending on the action categories (i.e., types of in-game player behaviour). Using the developed traffic model we prove that while server population only modifies specific action categories, this effect is significant enough to be observed on the overall traffic. We find that TCP Vegas is a good option for competing flows in order not to throttle the MMORPG flows and that TCP SACK is more respectful with game flows than other TCP variants, namely, Tahoe, Reno, and New Reno. Other tests show that MMORPG flows do not significantly reduce their sending window size when competing against UDP flows. Additionally, we study the effect of RTT unfairness between MMORPG flows, showing that it is less important than in the case of network-limited TCP flows. Mirko Suznjevic, Jose Saldana, Maja Matijasevic, Julián Fernández-Navajas, and José Ruiz-Mas Copyright © 2014 Mirko Suznjevic et al. All rights reserved. Desirable Elements for a Particle System Interface Sun, 05 Jan 2014 14:37:49 +0000 http://www.hindawi.com/journals/ijcgt/2014/623809/ Particle systems have many applications, with the most popular being to produce special effects in video games and films. To permit particle systems to be created quickly and easily, Particle System Interfaces (PSIs) have been developed. A PSI is a piece of software designed to perform common tasks related to particle systems for clients, while providing them with a set of parameters whose values can be adjusted to create different particle systems. Most PSIs are inflexible, and when clients require functionality that is not supported by the PSI they are using, they are forced to either find another PSI that meets their requirements or, more commonly, create their own particle system or PSI from scratch. This paper presents three original contributions. First, it identifies 18 features that a PSI should provide in order to be capable of creating diverse effects. If these features are implemented in a PSI, clients will be more likely to be able to accomplish all desired effects related to particle systems with one PSI. Secondly, it introduces a novel use of events to determine, at run time, which particle system code to execute in each frame. Thirdly, it describes a software architecture called the Dynamic Particle System Framework (DPSF). Simulation results show that DPSF possesses all 18 desirable features. Daniel Schroeder and Howard J. Hamilton Copyright © 2014 Daniel Schroeder and Howard J. Hamilton. All rights reserved. Procedural Audio in Computer Games Using Motion Controllers: An Evaluation on the Effect and Perception Mon, 23 Dec 2013 11:28:52 +0000 http://www.hindawi.com/journals/ijcgt/2013/371374/ A study has been conducted into whether the use of procedural audio affects players in computer games using motion controllers. It was investigated whether or not (1) players perceive a difference between detailed and interactive procedural audio and prerecorded audio, (2) the use of procedural audio affects their motor-behavior, and (3) procedural audio affects their perception of control. Three experimental surveys were devised, two consisting of game sessions and the third consisting of watching videos of gameplay. A skiing game controlled by a Nintendo Wii balance board and a sword-fighting game controlled by a Wii remote were implemented with two versions of sound, one sample based and the other procedural based. The procedural models were designed using a perceptual approach and by alternative combinations of well-known synthesis techniques. The experimental results showed that, when being actively involved in playing or purely observing a video recording of a game, the majority of participants did not notice any difference in sound. Additionally, it was not possible to show that the use of procedural audio caused any consistent change in the motor behavior. In the skiing experiment, a portion of players perceived the control of the procedural version as being more sensitive. Niels Böttcher, Héctor P. Martínez, and Stefania Serafin Copyright © 2013 Niels Böttcher et al. All rights reserved. Reconstructing 3D Tree Models Using Motion Capture and Particle Flow Thu, 07 Nov 2013 15:41:59 +0000 http://www.hindawi.com/journals/ijcgt/2013/363160/ Recovering tree shape from motion capture data is a first step toward efficient and accurate animation of trees in wind using motion capture data. Existing algorithms for generating models of tree branching structures for image synthesis in computer graphics are not adapted to the unique data set provided by motion capture. We present a method for tree shape reconstruction using particle flow on input data obtained from a passive optical motion capture system. Initial branch tip positions are estimated from averaged and smoothed motion capture data. Branch tips, as particles, are also generated within a bounding space defined by a stack of bounding boxes or a convex hull. The particle flow, starting at branch tips within the bounding volume under forces, creates tree branches. The forces are composed of gravity, internal force, and external force. The resulting shapes are realistic and similar to the original tree crown shape. Several tunable parameters provide control over branch shape and arrangement. Jie Long and Michael D. Jones Copyright © 2013 Jie Long and Michael D. Jones. All rights reserved. Adaptive-AR Model with Drivers’ Prediction for Traffic Simulation Thu, 26 Sep 2013 15:31:15 +0000 http://www.hindawi.com/journals/ijcgt/2013/904154/ We present a novel model called A2R—“Adaptive-AR”—based on a well-known continuum-based model called AR Aw and Rascle (2000) for the simulation of vehicle traffic flows. However, in the standard continuum-based model, vehicles usually follow the flows passively, without taking into account drivers' behavior and effectiveness. In order to simulate real-life traffic flows, we extend the model with a few factors, which include the effectiveness of drivers' prediction, drivers' reaction time, and drivers' types. We demonstrate that our A2R model is effective and the results of the experiments agree well with experience in real world. It has been shown that such a model makes vehicle flows perform more realistically and is closer to the real-life traffic than AR (short for Aw and Rascle and introduced in Aw and Rascle (2000)) model while having a similar performance. Xuequan Lu, Mingliang Xu, Wenzhi Chen, Zonghui Wang, and Abdennour El Rhalibi Copyright © 2013 Xuequan Lu et al. All rights reserved. Effects of Wind on Virtual Plants in Animation Sun, 15 Sep 2013 13:38:23 +0000 http://www.hindawi.com/journals/ijcgt/2013/674848/ This paper presents the Growth-Flow method for animating the effect of wind on the motion and growth of virtual plant branches and leaves. The method incorporates changes to the growth rate when a plant is exposed to winds with speeds higher than a threshold. In particular, growth rate is reduced in branch elongation, increased in the branch radius, reduced in leaf length, and increased in leaf thickness. In addition, when a plant is exposed to wind for long time periods, the branch growth angle is changed to align more closely with the wind vector. The Growth-Flow method incorporates all these effects on growth and motion due to wind in one algorithm. Tina L. M. Derzaph and Howard J. Hamilton Copyright © 2013 Tina L. M. Derzaph and Howard J. Hamilton. All rights reserved. Comparing Expert Driving Behavior in Real World and Simulator Contexts Sun, 18 Aug 2013 11:08:54 +0000 http://www.hindawi.com/journals/ijcgt/2013/891431/ Computer games are increasingly used for purposes beyond mere entertainment, and current hi-tech simulators can provide quite, naturalistic contexts for purposes such as traffic education. One of the critical concerns in this area is the validity or transferability of acquired skills from a simulator to the real world context. In this paper, we present our work in which we compared driving in the real world with that in the simulator at two levels, that is, by using performance measures alone, and by combining psychophysiological measures with performance measures. For our study, we gathered data using questionnaires as well as by logging vehicle dynamics, environmental conditions, video data, and users' psychophysiological measurements. For the analysis, we used several novel approaches such as scatter plots to visualize driving tasks of different contexts and to obtain vigilance estimators from electroencephalographic (EEG) data in order to obtain important results about the differences between the driving in the two contexts. Our belief is that both experimental procedures and findings of our experiment are very important to the field of serious games concerning how to evaluate the fitness of driving simulators and measure driving performance. Hiran B. Ekanayake, Per Backlund, Tom Ziemke, Robert Ramberg, Kamalanath P. Hewagamage, and Mikael Lebram Copyright © 2013 Hiran B. Ekanayake et al. All rights reserved. Petri Net Model for Serious Games Based on Motivation Behavior Classification Thu, 04 Apr 2013 09:05:49 +0000 http://www.hindawi.com/journals/ijcgt/2013/851287/ Petri nets are graphical and mathematical tool for modeling, analyzing, and designing discrete event applicable to many systems. They can be applied to game design too, especially to design serous game. This paper describes an alternative approach to the modeling of serious game systems and classification of motivation behavior with Petri nets. To assess the motivation level of player ability, this research aims at Motivation Behavior Game (MBG). MBG improves this motivation concept to monitor how players interact with the game. This modeling employs Learning Vector Quantization (LVQ) for optimizing the motivation behavior input classification of the player. MBG may provide information when a player needs help or when he wants a formidable challenge. The game will provide the appropriate tasks according to players’ ability. MBG will help balance the emotions of players, so players do not get bored and frustrated. Players have a high interest to finish the game if the players are emotionally stable. Interest of the players strongly supports the procedural learning in a serious game. Moh. Aries Syufagi, Mochamad Hariadi, and Mauridhi Hery Purnomo Copyright © 2013 Moh. Aries Syufagi et al. All rights reserved. The Brigade Renderer: A Path Tracer for Real-Time Games Sun, 17 Mar 2013 16:12:45 +0000 http://www.hindawi.com/journals/ijcgt/2013/578269/ We present the Brigade renderer: an efficient system that uses the path tracing algorithm to produce images for real-time games. We describe the architecture of the Brigade renderer, and provide implementation details. We describe two games that have been created using Brigade. Jacco Bikker and Jeroen van Schijndel Copyright © 2013 Jacco Bikker and Jeroen van Schijndel. All rights reserved. User Experiences While Playing Dance-Based Exergames and the Influence of Different Body Motion Sensing Technologies Wed, 20 Feb 2013 15:47:12 +0000 http://www.hindawi.com/journals/ijcgt/2013/603604/ Dance Dance Revolution is a pioneering exergame which has attracted considerable interest for its potential to promote regular exercise and its associated health benefits. The advent of a range of different consumer body motion tracking video game console peripherals raises the question whether their different technological affordances (i.e., variations in the type and number of body limbs that they can track) influence the user experience while playing dance-based exergames both in terms of the level of physical exertion and the nature of the play experience. To investigate these issues a group of subjects performed a total of six comparable dance routines selected from commercial dance-based exergames (two routines from each game) on three different consoles. The subjects’ level of physical exertion was assessed by measuring oxygen consumption and heart rate. They also reported their perceived level of exertion, difficulty, and enjoyment ratings after completing each dance routine. No differences were found in the physiological measures of exertion between the peripherals/consoles. However, there were significant variations in the difficulty and enjoyment ratings between peripherals. The design implications of these results are discussed including the tension between helping to guide and coordinate player movement versus offering greater movement flexibility. Alasdair G. Thin, Craig Brown, and Paul Meenan Copyright © 2013 Alasdair G. Thin et al. All rights reserved. Single- versus Multiobjective Optimization for Evolution of Neural Controllers in Ms. Pac-Man Mon, 18 Feb 2013 07:22:24 +0000 http://www.hindawi.com/journals/ijcgt/2013/170914/ The objective of this study is to focus on the automatic generation of game artificial intelligence (AI) controllers for Ms. Pac-Man agent by using artificial neural network (ANN) and multiobjective artificial evolution. The Pareto Archived Evolution Strategy (PAES) is used to generate a Pareto optimal set of ANNs that optimize the conflicting objectives of maximizing Ms. Pac-Man scores (screen-capture mode) and minimizing neural network complexity. This proposed algorithm is called Pareto Archived Evolution Strategy Neural Network or PAESNet. Three different architectures of PAESNet were investigated, namely, PAESNet with fixed number of hidden neurons (PAESNet_F), PAESNet with varied number of hidden neurons (PAESNet_V), and the PAESNet with multiobjective techniques (PAESNet_M). A comparison between the single- versus multiobjective optimization is conducted in both training and testing processes. In general, therefore, it seems that PAESNet_F yielded better results in training phase. But the PAESNet_M successfully reduces the runtime operation and complexity of ANN by minimizing the number of hidden neurons needed in hidden layer and also it provides better generalization capability for controlling the game agent in a nondeterministic and dynamic environment. Tse Guan Tan, Jason Teo, and Kim On Chin Copyright © 2013 Tse Guan Tan et al. All rights reserved. Analysis of Motivational Elements of Social Games: A Puzzle Match 3-Games Study Case Sun, 30 Dec 2012 15:45:23 +0000 http://www.hindawi.com/journals/ijcgt/2012/640725/ The main motivational elements of the social network sites and the social network games will be shown according to studies already existent in the literature, highlighting the elements which motivate the players the most to play social Match 3-type games. Seven games have been analyzed: Diamond Dash, Collapse!Blast, Mystic Ice Blast, Bricks Breaking, Plock, Gem Clix, and Blast!. The results showed that asynchronous time, activities publishing, rewarding system, competition, and social status are the elements which motivate and stimulate the most the players to play. Marcel Toshio Omori and Alan Salvany Felinto Copyright © 2012 Marcel Toshio Omori and Alan Salvany Felinto. All rights reserved. A Guideline for Game Development-Based Learning: A Literature Review Sat, 29 Dec 2012 13:57:25 +0000 http://www.hindawi.com/journals/ijcgt/2012/103710/ This study aims at reviewing the published scientific literature on the topics of a game development-based learning (GDBL) method using game development frameworks (GDFs) with the perspective of (a) summarizing a guideline for using GDBL in a curriculum, (b) identifying relevant features of GDFs, and (c) presenting a synthesis of impact factors with empirical evidence on the educational effectiveness of the GDBL method. After systematically going through the available literature on the topic, 34 relevant articles were selected for the final study. We analyzed the articles from three perspectives: (1) pedagogical context and teaching process, (2) selection of GDFs, and (3) evaluation of the GDBL method. The findings from the 34 articles suggest that GDFs have many potential benefits as an aid to teach computer science, software engineering, art design, and other fields and that such GDFs combined with the motivation from games can improve the students’ knowledge, skills, attitudes, and behaviors in contrast to the traditional classroom teaching. Furthermore, based on the results of the literature review, we extract a guideline of how to apply the GDBL method in education. The empirical evidence of current findings gives a positive overall picture and can provide a useful reference to educators, practitioners, and researchers in the area of game-based learning. Bian Wu and Alf Inge Wang Copyright © 2012 Bian Wu and Alf Inge Wang. All rights reserved. Building Community and Collaboration Applications for MMOGs Tue, 11 Sep 2012 10:58:26 +0000 http://www.hindawi.com/journals/ijcgt/2012/969785/ Supporting collaborative activities among the online players are one of the major challenges in the area of Massively Multiplayer Online Games (MMOG), since they increase the richness of gaming experience and create more engaged communities. To this direction, our study has focused on the provision of services supporting and enhancing the players' in-game community and collaboration activities. We have designed and implemented innovative tools exploiting a game adaptation technology, namely, the In-game Graphical Insertion Technology (IGIT), which permits the addition of web-based applications without any need from the game developers to modify the game at all, nor from the game players to change their game installation. The developed tools follow a design adapted to the MMOG players' needs and are based on the latest advances on Web 2.0 technology. Their provision is performed through the core element of our system, which is the so-called Community Network Game (CNG) Server. One of the important features provided by the implemented system's underlying framework is the utilization of enhanced Peer-to-Peer (P2P) technology for the distribution of user-generated live video streams. In this paper, we focus on the architecture of the CNG Server as well as on the design and implementation of the online community and collaboration tools. George Adam, Christos Bouras, Vaggelis Kapoulas, and Andreas Papazois Copyright © 2012 George Adam et al. All rights reserved. Comparison of Learning Software Architecture by Developing Social Applications versus Games on the Android Platform Tue, 11 Sep 2012 08:30:12 +0000 http://www.hindawi.com/journals/ijcgt/2012/494232/ This paper describes an empirical study where the focus was on discovering differences and similarities in students working on development of social applications versus students working on development of games using the same Android development platform. In 2010-2011, students attending the software architecture course at the Norwegian University of Science and Technology (NTNU) could choose between four types of projects. Independently of the chosen type of project, all students had to go through the same phases, produce the same documents based on the same templates, and follow exactly the same process. This study focuses on one of projects—Android project, to see how much the application domain affects the course project independently of the chosen technology. Our results revealed some positive effects for the students doing game development compared to social application development to learn software architecture, like motivated to work with games, a better focus on quality attributes such as modifiability and testability during the development, production of software architectures of higher complexity, and more productive coding working for the project. However, we did not find significant differences in awarded grade between students choosing the two different domains. Bian Wu and Alf Inge Wang Copyright © 2012 Bian Wu and Alf Inge Wang. All rights reserved. A Framework for Adaptive Game Presenters with Emotions and Social Comments Thu, 06 Sep 2012 11:37:57 +0000 http://www.hindawi.com/journals/ijcgt/2012/929814/ More and more games today try to adjust their gameplay to fit individual players; however, little work has been carried out in the same direction towards game presenter characters. Game commentary should take into account players' personalities along with game progress in order to achieve social player-adapted comment delivery that boosts the overall gameplay, engages the players, and stimulates the audience. In our work, we discuss a framework for implementing artificial game presenter characters that are based on game actions and players' social profiles in order to deliver knowledgeable, socially oriented comments. Moreover, the presented framework supports emotional facial expressions for the presenters, allowing them to convey their emotions and thus be more expressive than the majority of the commentary systems today. We prove our concept by developing a presenter character for multiplayer tabletop board games which we further put under usability evaluation with 9 players. The results showed that game sessions with presenter characters are preferred over the plain version of the game and that the majority of the players enjoy personalized social-oriented comments expressed via multimedia and emotions. Effie Karouzaki and Anthony Savidis Copyright © 2012 Effie Karouzaki and Anthony Savidis. All rights reserved. Dynamic Difficulty Balancing for Cautious Players and Risk Takers Wed, 27 Jun 2012 11:24:01 +0000 http://www.hindawi.com/journals/ijcgt/2012/625476/ Dynamic balancing of game difficulty can help cater for different levels of ability in players. However, performance in some game tasks depends on not only the player's ability but also their desire to take risk. Taking or avoiding risk can offer players its own reward in a game situation. Furthermore, a game designer may want to adjust the mechanics differently for a risky, high ability player, as opposed to a risky, low ability player. In this work, we describe a novel modelling technique known as particle filtering which can be used to model various levels of player ability while also considering the player's risk profile. We demonstrate this technique by developing a game challenge where players are required to make a decision between a number of possible alternatives where only a single alternative is correct. Risky players respond faster but with more likelihood of failure. Cautious players wait longer for more evidence, increasing their likelihood of success, but at the expense of game time. By gathering empirical data for the player's response time and accuracy, we develop particle filter models. These models can then be used in real-time to categorise players into different ability and risk-taking levels. Guy Hawkins, Keith Nesbitt, and Scott Brown Copyright © 2012 Guy Hawkins et al. All rights reserved. More Than Flow: Revisiting the Theory of Four Channels of Flow Fri, 15 Jun 2012 16:01:35 +0000 http://www.hindawi.com/journals/ijcgt/2012/724917/ Flow (FCF) theory has received considerable attention in recent decades. In addition to flow, FCF theory proposed three influential factors, that is, boredom, frustration, and apathy. While these factors have received relatively less attention than flow, Internet applications have grown exponentially, warranting a closer reexamination of the applicability of the FCF theory. Thus, this study tested the theory that high/low levels of skill and challenge lead to four channels of flow. The study sample included 253 online gamers who provided valid responses to an online survey. Analytical results support the FCF theory, although a few exceptions were noted. First, skill was insignificantly related to apathy, possibly because low-skill users can realize significant achievements to compensate for their apathy. Moreover, in contrast with the FCF theory, challenge was positively related to boredom, revealing that gamers become bored with difficult yet repetitive challenges. Two important findings suggest new directions for FCF theory. Ching-I Teng and Han-Chung Huang Copyright © 2012 Ching-I Teng and Han-Chung Huang. All rights reserved. Development of Embedded CAPTCHA Elements for Bot Prevention in Fischer Random Chess Mon, 04 Jun 2012 10:12:10 +0000 http://www.hindawi.com/journals/ijcgt/2012/178578/ Cheating in chess can take many forms and has existed almost as long as the game itself. The advent of computers has introduced a new form of cheating into the game. Thanks to the computational power of modern-day computers, a player can use a program to calculate thousands of moves for him or her, and determine the best possible scenario for each move and countermove. These programs are often referred to as “bots,” and can even play the game without any user interaction. In this paper, we describe a methodology aimed at preventing bots from participating in online chess games. The proposed approach is based on the integration of a CAPTCHA protocol into a game scenario, and the subsequent inability of bots to accurately track the game states. This is achieved by rotating the images of the individual chess pieces and adjusting their resolution in an attempt to render them unreadable by a bot. Feedback from users during testing shows that there is minimal impact on their ability to play the game. Players rated the difficulty of reading the pieces on a scale of one to ten, with an average rank of 6.5. However, the average number of moves to adjust to the distorted pieces was only 3.75. This tells us that, although it is difficult to read the pieces at first, it is easy to adjust quickly to the new image. Ryan McDaniel and Roman V. Yampolskiy Copyright © 2012 Ryan McDaniel and Roman V. Yampolskiy. All rights reserved. Pose Space Surface Manipulation Tue, 15 May 2012 19:36:04 +0000 http://www.hindawi.com/journals/ijcgt/2012/596953/ Example-based mesh deformation techniques produce natural and realistic shapes by learning the space of deformations from examples. However, skeleton-based methods cannot manipulate a global mesh structure naturally, whereas the mesh-based approaches based on a translational control do not allow the user to edit a local mesh structure intuitively. This paper presents an example-driven mesh editing framework that achieves both global and local pose manipulations. The proposed system is built with a surface deformation method based on a two-step linear optimization technique and achieves direct manipulations of a model surface using translational and rotational controls. With the translational control, the user can create a model in natural poses easily. The rotational control can adjust the local pose intuitively by bending and twisting. We encode example deformations with a rotation-invariant mesh representation which handles large rotations in examples. To incorporate example deformations, we infer a pose from the handle translations/rotations and perform pose space interpolation, thereby avoiding involved nonlinear optimization. With the two-step linear approach combined with the proposed multiresolution deformation method, we can edit models at interactive rates without losing important deformation effects such as muscle bulging. Yusuke Yoshiyasu and Nobutoshi Yamazaki Copyright © 2012 Yusuke Yoshiyasu and Nobutoshi Yamazaki. All rights reserved. Concert Viewing Headphones Tue, 07 Feb 2012 08:01:23 +0000 http://www.hindawi.com/journals/ijcgt/2011/612535/ An audiovisual interface equipped with a projector, an inclina-tion sensor, and a distance sensor for zoom control has been developed that enables a user to selectively view and listen to specific performers in a video-taped group performance. Dubbed Concert Viewing Headphones, it has both image and sound processing functions. The image processing extracts the portion of the image indicated by the user and projects it free of distortion on the front and side walls. The sound processing creates imaginary microphones for those performers without one so that the user can hear the sound from any performer. Testing using images and sounds captured using a fisheye-lens camera and 37 lavalier microphones showed that sound locali-zation was fastest when an inverse square function was used for the sound mixing and that the zoom function was useful for locating the desired sound performance. Kazuya Atsuta, Masatoshi Hamanaka, and SeungHee Lee Copyright © 2011 Kazuya Atsuta et al. All rights reserved. Epitomize Your Photos Mon, 06 Feb 2012 17:33:44 +0000 http://www.hindawi.com/journals/ijcgt/2011/706893/ With the rapid growth of digital photography, sharing of photos with friends and family has become very popular. When people share their photos, they usually organize them into albums according to events or places. To tell the story of some important events in one’s life, it is desirable to have an efficient summarization tool which can help people to receive a quick overview of an album containing large number of photos. In this paper, we present and analyze an approach for photo album summarization through a novel social game “Epitome” as a Facebook application. This social game can collect research data, and, at the same time, it provides a collage or a cover photo of the user’s photo album, while the user enjoys playing the game. The proof of concept of the proposed method is demonstrated through a set of experiments on several photo albums. As a benchmark comparison to this game, we perform automatic visual analysis considering several state-of-the-art features. We also evaluate the usability of the game by making use of a questionnaire on several subjects who played the “Epitome” game. Furthermore, we address privacy issues concerning shared photos in Facebook applications. Peter Vajda, Ivan Ivanov, Jong-Seok Lee, and Touradj Ebrahimi Copyright © 2011 Peter Vajda et al. All rights reserved. Enhancing a Commercial Game Engine to Support Research on Route Realism for Synthetic Human Characters Thu, 02 Feb 2012 14:11:37 +0000 http://www.hindawi.com/journals/ijcgt/2011/819746/ Generating routes for entities in virtual environments, such as simulated vehicles or synthetic human characters, is a long-standing problem, and route planning algorithms have been developed and studied for some time. Existing route planning algorithms, including the widely used A* algorithm, are generally intended to achieve optimality in some metric, such as minimum length or minimum time. Comparatively little attention has been given to route realism, defined as the similarity of the algorithm-generated route to the route followed by real humans in the same terrain with the same constraints and goals. Commercial game engines have seen increasing use as a context for research. To study route realism in a game engine, two developments were needed: a quantitative metric for measuring route realism and a game engine able to capture route data needed to compute the realism metric. Enhancements for recording route data for both synthetic characters and human players were implemented within the Unreal Tournament 2004 game engine. A methodology for assessing the realism of routes and other behaviors using a quantitative metric was developed. The enhanced Unreal Tournament 2004 game engine and the realism assessment methodology were tested by capturing data required to calculate a metric of route realism. Gregg T. Hanold and Mikel D. Petty Copyright © 2011 Gregg T. Hanold and Mikel D. Petty. All rights reserved. Immersion in Computer Games: The Role of Spatial Presence and Flow Thu, 05 Jan 2012 09:20:36 +0000 http://www.hindawi.com/journals/ijcgt/2011/282345/ A main reason to play computer games is the pleasure of being immersed in a mediated world. Spatial presence and flow are considered key concepts to explain such immersive experiences. However, little attention has been paid to the connection between the two concepts. Thus, we empirically examined the relationship between presence and flow in the context of a computer role-playing game (𝑁=70), a racing game (𝑁=120), and a jump and run game (𝑁=72). In all three studies, factor analysis revealed that presence and flow are distinct constructs, which do hardly share common variance. We conclude that presence refers to the sensation of being there in the mediated world, whereas flow rather refers to the sensation of being involved in the gaming action. Further analyses showed that flow and presence depend on motivation and immersive tendency. In addition, flow and presence enhanced performance as well as enjoyment. David Weibel and Bartholomäus Wissmath Copyright © 2011 David Weibel and Bartholomäus Wissmath. All rights reserved. MovieRemix: Having Fun Playing with Videos Thu, 29 Dec 2011 16:02:48 +0000 http://www.hindawi.com/journals/ijcgt/2011/857371/ The process of producing new creative videos by editing, combining, and organizing pre-existing material (e.g., video shots) is a popular phenomenon in the current web scenario. Known as remix or video remix, the produced video may have new and different meanings with respect to the source material. Unfortunately, when managing audiovisual objects, the technological aspect can be a burden for many creative users. Motivated by the large success of the gaming market, we propose a novel game and an architecture to make the remix process a pleasant and stimulating gaming experience. MovieRemix allows people to act like a movie director, but instead of dealing with cast and cameras, the player has to create a remixed video starting from a given screenplay and from video shots retrieved from the provided catalog. MovieRemix is not a simple video editing tool nor is a simple game: it is a challenging environment that stimulates creativity. To temp to play the game, players can access different levels of screenplay (original, outline, derived) and can also challenge other players. Computational and storage issues are kept at the server side, whereas the client device just needs to have the capability of playing streaming videos. Nicola Dusi, Maria Federico, and Marco Furini Copyright © 2011 Nicola Dusi et al. All rights reserved. Expressive Animated Character Sequences Using Knowledge-Based Painterly Rendering Thu, 03 Nov 2011 15:36:45 +0000 http://www.hindawi.com/journals/ijcgt/2011/164949/ We propose a technique to enhance emotional expressiveness in games and animations. Artists have used colors and painting techniques to convey emotions in their paintings for many years. Moreover, researchers have found that colors and line properties affect users' emotions. We propose using painterly rendering for character sequences in games and animations with a knowledge-based approach. This technique is especially useful for parametric facial sequences. We introduce two parametric authoring tools for animation and painterly rendering and a method to integrate them into a knowledge-based painterly rendering system. Furthermore, we present the results of a preliminary study on using this technique for facial expressions in still images. The results of the study show the effect of different color palettes on the intensity perceived for an emotion by users. The proposed technique can provide the animator with a depiction tool to enhance the emotional content of a character sequence in games and animations. Hasti Seifi, Steve DiPaola, and Ali Arya Copyright © 2011 Hasti Seifi et al. All rights reserved. Using Game Development to Teach Software Architecture Mon, 04 Jul 2011 08:51:48 +0000 http://www.hindawi.com/journals/ijcgt/2011/920873/ This paper describes a case study of how a game project using the XNA Game Studio from Microsoft was implemented in a software architecture course. In this project, university students have to construct and design a type of software architecture, evaluate the architecture, implement an application based on the architecture, and test this implementation. In previous years, the domain of the software architecture project has been a robot controller for navigating a maze. Robot controller was chosen as the domain for the project, as there exist several papers and descriptions on reference architectures for managing mobile robots. This paper describes the changes we had to make to introduce an XNA game development project to the software architecture course, and our experiences from running a software architecture project focusing on game development and XNA. The experiences described in this paper are based on feedback from the course staff, the project reports of the students, and a mandatory course evaluation. The evaluation shows among other things that the majority of the students preferred the game project to the robot project, that XNA was considered to be suitable platform for a software architecture project, that the students found it useful to learn XNA and C#, and that some students were carried away when developing the game in the software architecture project. Alf Inge Wang and Bian Wu Copyright © 2011 Alf Inge Wang and Bian Wu. All rights reserved. Determining Solution Space Characteristics for Real-Time Strategy Games and Characterizing Winning Strategies Sun, 03 Jul 2011 09:07:59 +0000 http://www.hindawi.com/journals/ijcgt/2011/834026/ The underlying goal of a competing agent in a discrete real-time strategy (RTS) game is to defeat an adversary. Strategic agents or participants must define an a priori plan to maneuver their resources in order to destroy the adversary and the adversary's resources as well as secure physical regions of the environment. This a priori plan can be generated by leveraging collected historical knowledge about the environment. This knowledge is then employed in the generation of a classification model for real-time decision-making in the RTS domain. The best way to generate a classification model for a complex problem domain depends on the characteristics of the solution space. An experimental method to determine solution space (search landscape) characteristics is through analysis of historical algorithm performance for solving the specific problem. We select a deterministic search technique and a stochastic search method for a priori classification model generation. These approaches are designed, implemented, and tested for a specific complex RTS game, Bos Wars. Their performance allows us to draw various conclusions about applying a competing agent in complex search landscapes associated with RTS games. Kurt Weissgerber, Gary B. Lamont, Brett J. Borghetti, and Gilbert L. Peterson Copyright © 2011 Kurt Weissgerber et al. All rights reserved.