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In the past decade, networked virtual environments (NVEs) have been an increasingly active area of research, with the first commercial systems emerging recently. Graphical and behavioral representation of users within such systems is a particularly important issue that has lagged in development behind other issues such as network architectures and...
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Analysis of existing ICT-based solutions for the education of long-term ill children reveal several weaknesses with respect to social and cooperative involvement, cost of development, and mobility issues. We present a scalable and affordable solution that supports both the social needs and learning process of these children. An educational platform...
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... Energy management and efficiency are beneficial societal goals. The simulation of virtual agents has been used in many applications, such as games (Silverman, Johns, Cornwell, & O'Brien, 2006b;Silverman, Bharathy, O'Brien, & Cornwell, 2006a), virtual environments (Pandzic et al., 2001), and evacuation scenarios (Helbing, Farkas, & Vicsek, 2000). In realistic scenarios, virtual agent behaviors should reflect analogous human responses to thermal *Correspondence to soraia.musse@pucrs.br. ...
Crowd simulation addresses algorithmic approaches to steering, navigation, perception, and behavioral models. Significant progress has been achieved in modeling interactions between agents and the environment to avoid collisions, exploit empirical local decision data, and plan efficient paths to goals. We address a relatively unexplored dimension of virtual human behavior: thermal perception, comfort, and appropriate behavioral responses. Thermal comfort is associated with the ambient environment, agent density factors, and interpersonal thermal feedback. A key feature of our approach is the temporal integration of both thermal exposure and occupant density to directly influence agent movements and behaviors (e.g., clothing changes) to increase thermal comfort. Empirical thermal comfort models are incorporated as a validation basis. Simple heat transfer models are used to model environment, agent, and interpersonal heat exchange. Our model’s generality makes it applicable to any existing crowd steering algorithm as it adds additional integrative terms to any cost function. Examples illustrate distinctive emergent behaviors such as balancing agent density with thermal comfort, hysteresis in responding to localized or brief thermal events, and discomfort and likely injury produced by extreme packing densities.
... A NIMATION of human-like virtual characters has potential applications in the design of human computer interfaces , computer games, and modeling of virtual environments using power-constrained devices such as laptop computers in battery mode, pocket PCs, and PDAs [1], [19]. Distributed virtual human animation is used in many applications that depict human models interacting with networked virtual environments [2]. Distributed virtual environments (DVEs) either require exchange of motion files between hosts to simulate the virtual human motion, or use locally stored motion data [3], [4], [5], [6], [23]. ...
Human Motion Capture (MoCap) data can be used for animation of virtual human-like characters in distributed virtual reality applications and networked games. MoCap data compressed using the standard MPEG-4 encoding pipeline comprising of predictive encoding (and/or DCT decorrelation), quantization, and arithmetic/Huffman encoding, entails significant power consumption for the purpose of decompression. In this paper, we propose a novel algorithm for compression of MoCap data, which is based on smart indexing of the MoCap data by exploiting structural information derived from the skeletal virtual human model. The indexing algorithm can be fine-controlled using three predefined quality control parameters (QCPs). We demonstrate how an efficient combination of the three QCPs results in a lower network bandwidth requirement and reduced power consumption for data decompression at the client end when compared to standard MPEG-4 compression. Since the proposed algorithm exploits structural information derived from the skeletal virtual human model, it is observed to result in virtual human animation of visually acceptable quality upon decompression.
... This structure is augmented with smart objects, which encode actions and rules that describe what can be accomplished with the objects as well as how the objects should be interacted with. This can be a powerful way to encode behaviors into environmental objects[5],[6]. In contrast, the EDF is independent of (but correlated with) the scene graph, relatively flat, and emphasizes the 3D ribbonlike structure of pathways. This simplifies motion planning and allows us to build fast, robust computations for accessing local geometry and the positions of nearby objects and recovering embedded content that guides agent decision making and actions. ...
This paper presents the Environment Description Framework (EDF) for modeling complex networks of intersecting roads and pathways in virtual environments. EDF represents information about the layout of streets and sidewalks, the rules that govern behavior on roads and walkways, and the locations of agents with respect to navigable structures. The framework serves as the substrate on which behavior programs for autonomous vehicles and pedestrians are built. Pathways are modeled as ribbons in space. The ribbon structure provides a natural coordinate frame for defining the local geometry of navigable surfaces. EDF includes a powerful runtime interface supported by robust and efficient code for locating objects on the ribbon network, for mapping between Cartesian and ribbon coordinates, and for determining behavioral constraints imposed by the environment.
... However, our technique is not restricted to predened deterministic animations. For example, when incorporating crowds of virtual humans to the platform, the crowd-control mechanism was attached to only one of the processes, which updates the other peers (Pandzic et al., 2001). As the behavior of the crowd is dependent on the (dynamic) content of the environment, it is difcult to predict movement and frames in advance. ...
A central aim of the COVEN project was to prototype large-scale applications of collaborative virtual environments (CVEs) that went beyond the existing state of the art. These applications were used in a series of real-scale networked trials that allowed us to gather many interesting human and technological results. To fulfill the technological and experimental goals of the project, we have modified an existing CVE platform: the DIVE (distributed interactive virtual environment) toolkit. In this paper, we present the different services and extensions that have been implemented within the platform during the four years of the project. Such a presentation will exemplify the different features that will have to be offered by nextgeneration CVE platforms. Implementation of the COVEN services has had implications at all levels of the platform: from a new networking layer through to mechanisms for high-level semantic modeling of applications.
... However, our technique is not restricted to predened deterministic animations. For example, when incorporating crowds of virtual humans to the platform, the crowd-control mechanism was attached to only one of the processes, which updates the other peers (Pandzic et al., 2001). As the behavior of the crowd is dependent on the (dynamic) content of the environment, it is difcult to predict movement and frames in advance. ...
A central aim of the COVEN project was to prototype large-scale applications of collaborative virtual environments (CVEs) that went beyond the existing state of the art. These applications were used in a series of real-scale networked trials that allowed us to gather many interesting human and technological results. To fulfill the technological and experimental goals of the project, we have modified an existing CVE platform: the DIVE (distributed interactive virtual environment) toolkit. In this paper, we present the different services and extensions that have been implemented within the platform during the four years of the project. Such a presentation will exemplify the different features that will have to be offered by nextgeneration CVE platforms. Implementation of the COVEN services has had implications at all levels of the platform: from a new networking layer through to mechanisms for high-level semantic modeling of applications.
Simulating virtual environments populated with virtual but realistic crowds requires dozens of different face and body geometries. We present GENESIS (GENeration of E-population based on Statistical Information), an application that allows automatic generation of desired population models. The aim of this application is to generate any population group that is statistically calculated to satisfy given properties. We divide the population generation module into the face part and the body part. Each of them is based on a database, which is an organization of information collected and processed from the real population dataset. Upon the specification of the population parameters by the user, GENESIS transforms them onto a number of queries to the underlying databases, and process the results from the database in a statistical manner, allowing dynamic generation of desired number of individuals while satisfying the given properties of on the overall population.
The popular virtual world, second life, presents a number of opportunities and limitations for the sharing of ideas in the information economy. In this paper we ask the question, dasiato what extent can second life simulate an actual face-to-face meeting?psila Many authors have written that tacit knowledge transfer requires face-to-face meetings, however, virtual reality technology can provide tools that enable people to show facial expressions, body language and concepts in graphical form. In this way it is possible to use computer mediated communication to convey nonverbal information that would normally be very difficult to share remotely. In this paper we explore how closely second life can simulate actual face-to-face communication. We give examples of lessons learned from students learning in second life, and make recommendations on how to support natural communication in online environments.
MonkeyBridge is a collaborative Augmented Reality (AR) game employing autonomous animated agents embodied by lifelike, animated virtual characters and "smart" physical objects. The game serves as a pilot application to examine how "smart" software and hardware components capable of observing and reacting to events in the physical and virtual world can be useful in AR applications. We describe the implementation details of our test setups as well as how autonomous agents offer a rich gaming experience in AR games.
