A survey of plasticity in 3D user interfaces
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paper_title: Adaptive Hypermedia

paper_content:

Adaptive hypermedia is a relatively new direction of research on the crossroads of hypermedia and user modeling. Adaptive hypermedia systems build a model of the goals, preferences and knowledge of each individual user, and use this model throughout the interaction with the user, in order to adapt to the needs of that user. The goal of this paper is to present the state of the art in adaptive hypermedia at the eve of the year 2000, and to highlight some prospects for the future. This paper attempts to serve both the newcomers and the experts in the area of adaptive hypermedia by building on an earlier comprehensive review (Brusilovsky, 1996; Brusilovsky, 1998).
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paper_title: Virtual environments: Three-dimensional menus: A survey and taxonomy

paper_content:

Various interaction techniques have been developed in the field of virtual and augmented reality. Whereas techniques for object selection, manipulation, travel, and wayfinding have already been covered in existing taxonomies in some detail, application control techniques have not yet been sufficiently considered. However, they are needed by almost every mixed reality application, e.g. for choosing from alternative objects or options. For this purpose a great variety of distinct three-dimensional (3D) menu selection techniques is available. This paper surveys existing 3D menus from the corpus of literature and classifies them according to various criteria. The taxonomy introduced here assists developers of interactive 3D applications to better evaluate their options when choosing, optimizing, and implementing a 3D menu technique. Since the taxonomy spans the design space for 3D menu solutions, it also aids researchers in identifying opportunities to improve or create novel virtual menu techniques.
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paper_title: 3D User Interfaces: Theory and Practice

paper_content:

Foreword. Preface. I. FOUNDATIONS OF 3D USER INTERFACES . 1. Introduction to 3D User Interfaces. What Are 3D User Interfaces? Why 3D User Interfaces? Terminology. Application Areas. Conclusion. 2. 3D User Interfaces: History and Roadmap. History of 3D UIs. Roadmap to 3D UIs. Scope of This Book. Conclusion. II. Hardware Technologies for 3D User Interfaces. 3. 3D User Interface Output Hardware. Introduction. Visual Displays. Auditory Displays. Haptic Displays. Design Guidelines: Choosing Output Devices for 3D User Interfaces. Conclusion. 4. 3D User Interface Input Hardware. Introduction. Desktop Input Devices. Tracking Devices. 3D Mice. Special-Purpose Input Devices. Direct Human Input. Home-Brewed Input Devices. Choosing Input Devices for 3D Interfaces. III. 3D INTERACTION TECHNIQUES. 5. Selection and Manipulation. Introduction. 3D Manipulation Tasks. Manipulation Techniques and Input Devices. Interaction Techniques for 3D Manipulation. Design Guidelines. 6. Travel. Introduction. 3D Travel Tasks. Travel Techniques. Design Guidelines. 7. Wayfinding. Introduction. Theoretical Foundations. User-Centered Wayfinding Support. Environment-Centered Wayfinding Support. Evaluating Wayfinding Aids. Design Guidelines. Conclusion. 8. System Control. Introduction. Classification. Graphical Menus. Voice Commands. Gestural Commands. Tools. Multimodal System Control Techniques. Design Guidelines. Case Study: Mixing System Control Methods. 8.10. Conclusion. 9. Symbolic Input. Introduction. Symbolic Input Tasks. Symbolic Input Techniques. Design Guidelines. Beyond Text and Number Entry. IV. DESIGNING AND DEVELOPING 3D USER INTERFACES. 10. Strategies for Designing and Developing 3D User Interfaces. Introduction. Designing for Humans. Inventing 3D User Interfaces. Design Guidelines. 11. Evaluation of 3D User Interfaces. Introduction. Background. Evaluation Metrics for 3D Interfaces. Distinctive Characteristics of 3D Interface Evaluation. Classification of 3D Evaluation Methods. Two Multimethod Approaches. Guidelines for 3D Interface Evaluation. V. THE FUTURE OF 3D USER INTERFACES. 12. Beyond Virtual: 3D User Interfaces for the Real World. Introduction. AR Interfaces as 3D Data Browsers. 3D Augmented Reality Interfaces. Augmented Surfaces and Tangible Interfaces. Tangible AR Interfaces. Agents in AR. Transitional AR-VR Interfaces. Conclusion. 13. The Future of 3D User Interfaces. Questions about 3D UI Technology. Questions about 3D Interaction Techniques. Questions about 3D UI Design and Development. Questions about 3D UI Evaluation. Million-Dollar Questions. Appendix A: Quick Reference Guide to 3D User Interface Mathematics. Scalars. Vectors. Points. Matrices. Quaternions. Bibliography. Index.
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paper_title: Plasticity of User Interfaces: Framework and Research Agenda

paper_content:

This paper introduces the notion of plasticity, a new property of interactive systems that denotes a particular type of user interface adaptation. Plasticity is the capacity of a user interface to withstand variations of both the system physical characteristics and the environment while preserving usability. Typically, a ‘plastic’ electronic agenda would run both on a workstation and on a hand-held computer without requiring a complete system redesign and re-implementation. We present a generic framework inspired by the model-based approach, for supporting the development of plastic user interfaces. Within this framework, a plastic user interface is specified once and serves multiple sources of physical variations. The goal is to guarantee usability continuity under variations in physical constraints while minimizing development and maintenance costs. This framework is illustrated with two simple case studies. Preliminary results and the state of the art in HCI open a new research agenda for the design and development of plastic user interfaces.
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paper_title: Using the AMACONT architecture for flexible adaptation of 3D web applications

paper_content:

Providing personalized content and applications which also address heterogeneous capabilities of multiple device types becomes a significant challenge of today's Web development. By now most of the work in the field of adaptive hypermedia is devoted to Web content such as hypertext, images, video, and animation, but rarely to three-dimensional graphics. Research on the adaptation of 3D graphics is still in its infancy. The generic approach introduced in this paper combines the AMACONT adaptive hypermedia architecture with the component-based 3D document model CONTIGRA to achieve 3D adaptation methods such as parametric, structural, and implicit rule-based adaptation as well as rich hypermedia adaptation across media boundaries. In addition a layered context modeling framework supports not only personalization, but also adaptation to device and other contexts. It is shown that the approach can be generalized to other XML-based 3D document formats, e.g. X3D.
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paper_title: Adaptive Hypermedia

paper_content:

Adaptive hypermedia is a relatively new direction of research on the crossroads of hypermedia and user modeling. Adaptive hypermedia systems build a model of the goals, preferences and knowledge of each individual user, and use this model throughout the interaction with the user, in order to adapt to the needs of that user. The goal of this paper is to present the state of the art in adaptive hypermedia at the eve of the year 2000, and to highlight some prospects for the future. This paper attempts to serve both the newcomers and the experts in the area of adaptive hypermedia by building on an earlier comprehensive review (Brusilovsky, 1996; Brusilovsky, 1998).
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paper_title: Intelligent User Interfaces : Survey and Research Directions

paper_content:

Computers are extremely effective information processors. However, for current, highly interactive usage, computers can only be as effective as the interface which is used to communicate with them. This report first examines the development of the user interface to place the intelligent interface in historical context. Following this is a survey of intelligent interface paradigms and techniques. These show how new interfaces can improve communication between humans and machines when the interface technology makes the leap from a passive tool-set to a pro-active assistant. These assistants, or agents, are viewed in the context of a new type of interactive, partial solution to previously insoluble problems.
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paper_title: PEGASE: A Generic and Adaptable Intelligent System for Virtual Reality Learning Environments

paper_content:

The context of this research is the creation of human learning environments using virtual reality. We propose the integration of a generic and adaptable intelligent tutoring system (Pegase) into a virtual environment. The aim of this environment is to instruct the learner, and to assist the instructor. The proposed system is created using a multi-agent system. This system emits a set of knowledge (actions carried out by the learner, knowledge about the field, etc.) which Pegase uses to make informed decisions. Our study focuses on the representation of knowledge about the environment, and on the adaptable pedagogical agent providing instructive assistance.
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paper_title: Understanding and Using Context

paper_content:

A device for detaching a sheet-shaped copy support from a moving photoconductive layer by fluid pressure. The device includes a nozzle arrangement which directs pressurized fluid, such as compressed air, toward a sheet of copy paper or other copy support. The action of the fluid on the copy support creates a suction pressure which draws the copy support toward the nozzle arrangement to detach the copy support from the photoconductive layer. When the copy support has moved into close proximity and generally overlying relationship with respect to the nozzle arrangement, the fluid is passed off generally tangentially with respect to the copy support to maintain a constant suction and to avoid undesirable oscillations of the copy support. This, in turn, eliminates the undesirable noise associated with such oscillations.
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paper_title: Methods and techniques of adaptive hypermedia

paper_content:

Adaptive hypermedia is a new direction of research within the area of adaptive and user model-based interfaces. Adaptive hypermedia (AH) systems build a model of the individual user and apply it for adaptation to that user, for example, to adapt the content of a hypermedia page to the user's knowledge and goals, or to suggest the most relevant links to follow. AH systems are used now in several application areas where the hyperspace is reasonably large and where a hypermedia application is expected to be used by individuals with different goals, knowledge and backgrounds. This paper is a review of existing work on adaptive hypermedia. The paper is centered around a set of identified methods and techniques of AH. It introduces several dimensions of classification of AH systems, methods and techniques and describes the most important of them.
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paper_title: A Survey of Context-Aware Mobile Computing Research

paper_content:

Context-aware computing is a mobile computing paradigm in which applications can discover and take advantage of contextual information (such as user location, time of day, nearby people and devices, and user activity). Since it was proposed about a decade ago, many researchers have studied this topic and built several context-aware applications to demonstrate the usefulness of this new technology. Context-aware applications (or the system infrastructure to support them), however, have never been widely available to everyday users. In this survey of research on context-aware systems and applications, we looked in depth at the types of context used and models of context information, at systems that support collecting and disseminating context, and at applications that adapt to the changing context. Through this survey, it is clear that context-aware research is an old but rich area for research. The difficulties and possible solutions we outline serve as guidance for researchers hoping to make context-aware computing a reality.
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paper_title: Plasticity of User Interfaces: Framework and Research Agenda

paper_content:

This paper introduces the notion of plasticity, a new property of interactive systems that denotes a particular type of user interface adaptation. Plasticity is the capacity of a user interface to withstand variations of both the system physical characteristics and the environment while preserving usability. Typically, a ‘plastic’ electronic agenda would run both on a workstation and on a hand-held computer without requiring a complete system redesign and re-implementation. We present a generic framework inspired by the model-based approach, for supporting the development of plastic user interfaces. Within this framework, a plastic user interface is specified once and serves multiple sources of physical variations. The goal is to guarantee usability continuity under variations in physical constraints while minimizing development and maintenance costs. This framework is illustrated with two simple case studies. Preliminary results and the state of the art in HCI open a new research agenda for the design and development of plastic user interfaces.
---
paper_title: Using the AMACONT architecture for flexible adaptation of 3D web applications

paper_content:

Providing personalized content and applications which also address heterogeneous capabilities of multiple device types becomes a significant challenge of today's Web development. By now most of the work in the field of adaptive hypermedia is devoted to Web content such as hypertext, images, video, and animation, but rarely to three-dimensional graphics. Research on the adaptation of 3D graphics is still in its infancy. The generic approach introduced in this paper combines the AMACONT adaptive hypermedia architecture with the component-based 3D document model CONTIGRA to achieve 3D adaptation methods such as parametric, structural, and implicit rule-based adaptation as well as rich hypermedia adaptation across media boundaries. In addition a layered context modeling framework supports not only personalization, but also adaptation to device and other contexts. It is shown that the approach can be generalized to other XML-based 3D document formats, e.g. X3D.
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paper_title: Context-aware computing applications

paper_content:

Describes systems that examine and react to an individual's changing context. Such systems can promote and mediate people's interactions with devices, computers and other people, and they can help navigate unfamiliar places. We believe that a limited amount of information covering a person's proximate environment is most important for this form of computing, since the interesting part of the world around us is what we can see, hear and touch. In this paper, we define context-aware computing and describe four categories of context-aware applications: proximate selection, automatic contextual reconfiguration, contextual information and commands, and content-triggered actions. Instances of these application types have been prototyped on the PARCTAB, a wireless palm-sized computer.
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paper_title: Plasticity of User Interfaces: Framework and Research Agenda

paper_content:

This paper introduces the notion of plasticity, a new property of interactive systems that denotes a particular type of user interface adaptation. Plasticity is the capacity of a user interface to withstand variations of both the system physical characteristics and the environment while preserving usability. Typically, a ‘plastic’ electronic agenda would run both on a workstation and on a hand-held computer without requiring a complete system redesign and re-implementation. We present a generic framework inspired by the model-based approach, for supporting the development of plastic user interfaces. Within this framework, a plastic user interface is specified once and serves multiple sources of physical variations. The goal is to guarantee usability continuity under variations in physical constraints while minimizing development and maintenance costs. This framework is illustrated with two simple case studies. Preliminary results and the state of the art in HCI open a new research agenda for the design and development of plastic user interfaces.
---
paper_title: Using the AMACONT architecture for flexible adaptation of 3D web applications

paper_content:

Providing personalized content and applications which also address heterogeneous capabilities of multiple device types becomes a significant challenge of today's Web development. By now most of the work in the field of adaptive hypermedia is devoted to Web content such as hypertext, images, video, and animation, but rarely to three-dimensional graphics. Research on the adaptation of 3D graphics is still in its infancy. The generic approach introduced in this paper combines the AMACONT adaptive hypermedia architecture with the component-based 3D document model CONTIGRA to achieve 3D adaptation methods such as parametric, structural, and implicit rule-based adaptation as well as rich hypermedia adaptation across media boundaries. In addition a layered context modeling framework supports not only personalization, but also adaptation to device and other contexts. It is shown that the approach can be generalized to other XML-based 3D document formats, e.g. X3D.
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paper_title: Network-Based Visualization of 3D Landscapes and City Models

paper_content:

To improve the visualization of large 3D landscapes and city models in a network environment, the authors use two different types of hierarchical level-of-detail models for terrain and groups of buildings. They also leverage the models to implement progressive streaming in both client-server and peer-to-peer network architectures. Visualizing large photorealistic 3D landscapes and city models has received significant attention over the last 10 years in the computer graphics community. More recently, the availability of broadband Internet access and Web-based visualization techniques is paving the way for large-scale 3D landscapes and city models for a variety of professional and mass-market services. To make such services appealing to a large audience, these 3D models must reach a sufficient level of realism and accuracy. Many solutions are now available to automatically generate 3D models of huge urban environments. Geographic information system (GIS) databases (such as terrain elevation grids, orthophotographs, and a building's footprint and height) provide a good basis for generating such models at affordable cost with minimum human intervention. In the future, the accuracy and realism of 3D city models will be improved thanks to recent progress in data capturing techniques.
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paper_title: Adaptation mechanism for three dimensional content within the MPEG-21 framework

paper_content:

The goal of the research is creation of an adaptation mechanism for the delivery of three-dimensional content. The adaptation of content, for various network and terminal capabilities - as well as for different user preferences, is a key feature that needs to be investigated. Current state-of-the art research of the adaptation shows promising results for specific purpose and limited types of content but still it is not well adaptable for the massive heterogeneous environments. We present a method for transmitting adapted thee-dimensional contents to multiple target devices. We present some theoretical and practical methods for adapting three-dimensional contents, which includes shapes and animation. We also discuss practical details to the integration of our methods into MPEG-21 and MPEG-4 architectures
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paper_title: AdapTIVE: an intelligent virtual environment and its application in e-commerce

paper_content:

This work presents an intelligent virtual environment, called AdapTIVE (adaptive three-dimensional intelligent and virtual environment), which has its structure and presentation customized according to users' interests and preferences (represented in a user model) and in accordance with insertion and removal of contents in this environment. An automatic content categorization process is applied to create content models, used in the spatial organization of the contents in the environment. An intelligent agent assists users during navigation in the environment and retrieval of relevant information. This is a promising approach for new and advanced forms of education, entertainment and e-commerce. In order to validate our approach, a case study of an e-commerce environment is presented.
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paper_title: Interaction techniques for older adults using touchscreen devices: a literature review

paper_content:

Several studies investigated different interaction techniques and input devices for older adults using touchscreen. This literature review analyses the population involved, the kind of tasks that were executed, the apparatus, the input techniques, the provided feedback, the collected data and author's findings and their recommendations. As conclusion, this review shows that age-related changes, previous experience with technologies, characteristics of handheld devices and use situations need to be studied.
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paper_title: Geometric and photometric registration for real-time augmented reality

paper_content:

This paper proposes an augmented reality system with correct representation of shading and shadow. To realize a seamless augmented reality system, we need to resolve certain problems. The geometric and photometric registration problems are particularly important. These problems require the position of light sources and user's viewpoint. The proposed system resolves these problems using a 3D marker which combines a 2D square marker and a mirror ball. The 2D marker and the ball are used to estimate the relationship between the real and virtual worlds and the positions of light sources in the real world, respectively.
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paper_title: Sto(ry)chastics: A Bayesian Network Architecture for User Modeling and Compuatational Storytelling for Interactive Spaces

paper_content:

This paper presents sto(ry)chastics, a user-centered approach for computational storytelling for real-time sensor-driven multimedia audiovisual stories, such as those that are triggered by the body in motion in a sensor-instrumented interactive narrative space. With sto(ry)chastics the coarse and noisy sensor inputs are coupled to digital media outputs via a user model, which is estimated probabilistically by a Bayesian network. To illustrate sto(ry)chastics, this paper describes the museum wearable, a device which delivers an audiovisual narration interactively in time and space to the visitor as a function of the estimated visitor type. The wearable relies on a custom-designed long-range infrared location-identification sensor to gather information on where and how long the visitor stops in the museum galleries and uses this information as input to, or observations of, a (dynamic) Bayesian network. The network has been tested and validated on observed visitor tracking data by parameter learning using the Expectation Maximization (EM) algorithm, and by performance analysis of the model with the learned parameters.
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paper_title: A Survey of Context-Aware Mobile Computing Research

paper_content:

Context-aware computing is a mobile computing paradigm in which applications can discover and take advantage of contextual information (such as user location, time of day, nearby people and devices, and user activity). Since it was proposed about a decade ago, many researchers have studied this topic and built several context-aware applications to demonstrate the usefulness of this new technology. Context-aware applications (or the system infrastructure to support them), however, have never been widely available to everyday users. In this survey of research on context-aware systems and applications, we looked in depth at the types of context used and models of context information, at systems that support collecting and disseminating context, and at applications that adapt to the changing context. Through this survey, it is clear that context-aware research is an old but rich area for research. The difficulties and possible solutions we outline serve as guidance for researchers hoping to make context-aware computing a reality.
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paper_title: Dynamic generation of personalized VRML content: a general approach and its application to 3D e-commerce

paper_content:

The capability of (semi)automatically adapting the content, structure, and/or presentation of a Web site to address the interests and preferences of each individual user is more and more considered as a key factor to increase user satisfaction and building customer loyalty. However, while a large body of literature is available about making traditional Web sites adaptive, it is surprising that no research effort has been yet devoted to the problem of adapting Web3D content and presentation. This paper focuses on this topic, proposing a general approach to build adaptive 3D Web sites, and illustrating a specific application of the approach to a 3D e-commerce case study. The architecture we propose, called AWE3D (Adaptive WEb 3D), is based on a combination of readily available and platform-independent Web technologies so that it can be reproduced by interested readers.
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paper_title: Semantic-based rules for 3D scene adaptation

paper_content:

3D data is democratizing on the Web as it becomes available to everybody on almost all access devices. Still, 3D data is a heavy medium, as it contains a lot of geometric and texture information. This complexity raises a lot of problems, especially when data initially designed for great capacity access devices, is to be deployed on small devices. Due to the great heterogeneity of access devices and of their users and usages, the adaptation of already designed data is an important issue. In this paper, we present a rule-based adaptation framework that deals with the adaptation of X3D scenes. An adaptation rule indicates a type of adaptation to be applied to a set of objects which fit with the rule criterion. A basic set of adaptation techniques are registered within the framework. The framework is flexible and additional adaptation engines can be registered in order to support large sets of adaptation techniques.
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paper_title: Enhanced decoupling of components in intelligent realtime interactive systems using ontologies

paper_content:

We introduce a technique to support decoupling in component-based, modular software architectures as a means to enhance nonfunctional requirements, i.e., to increase reusability, portability, and adaptability. The core idea utilizes a semantic description of interfaces and component interplay in the area of Intelligent Real-time Interactive Systems (IRIS). Semantic descriptions are encoded as OWL-based models, which build a Knowledge Representation Layer (KRL) of relevant interface constructs and component features. These models are automatically transformed into programming language code of a given target language. The result of that transformation forms a semantically grounded database of relevant system aspects that programmers can use to develop their application. Examples, taken from an application that was developed with the Simulator X framework, illustrate the different aspects of the proposed method and demonstrate its practicability.
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paper_title: Ontology and rule based retrieval of sound objects in augmented audio reality system for museum visitors

paper_content:

ec(h)o is an "augmented reality interface" utilizing spatialized soundscapes and a semantic web approach to information. The initial prototype is designed for a natural history and science museum. The platform is designed to create a museum experience that consists of a physical installation and an interactive virtual layer of three-dimensional soundscapes that are physically mapped to the museum displays. The source for the audio data is digital sound objects. The digital objects originate in a network of object repositories that connect digital content from one museum with other museums collections. The interface enables people to interact with the system by movement and object manipulation-based gestures without the direct use of a computer device. The focus of this paper is the retrieval mechanism for the sound objects for the museum visitor. The retrieval mechanism is built on the user model and conceptual descriptions of the sound object and museum artifacts in the form of ontologies for sound and psychoacoustics, topic ontology and Conceptual Reference Model for museum information. The retrieval criteria are represented as inference rules that represent knowledge from psychoacoustics, cognitive domain and composition aspects of interaction. The system will be demonstrated in exhibition space in Nature Museum in Ottawa in January 2003.
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paper_title: Semantic modeling of Virtual Environments using MASCARET

paper_content:

Many Virtual Reality (VR) applications, such as Virtual Learning Environments or Interactive Virtual Tours, are based on a rich semantic description of the environment and tasks that users have to perform. These applications are built upon Virtual Environments (VEs) in which artificial agents act autonomously while interacting in realtime with users. Semantic modelling of a VR environment makes it possible the knowledge-driven access from the description of VEs that simplifies the development of VR applications. It eases the development of these types of applications. Semantic modelling should provide a consistent representation of the following aspects: 1) The simulated world, its structure and the behavior of its entities, 2) Interactions and tasks, that users and agents can perform in the environment, 3) Knowledge items, that autonomous agents can use for decision-making or for communication with users. This paper presents MASCARET, a model-based approach, for the design of semantic VR environments. This approach is based on the Unified Modeling Language (UML). In this approach, UML is used to provide a knowledge-driven access to the semantic contents of the VE and not for code generation, as in classical software development process. Interests of a UML-based approach are that its metamodel covers different views of the semantic modelling: ontology, structure, behaviors, interactions, activities. It is also an extensible language that can be specialized to provide formal operational semantics. We also present how MASCARET can be used to develop content-rich interactive applications that can be deployed over various VR platforms. Finally, we discuss the benefits of such a metamodel-based approach and show how the multi-layer semantic model can be used in different VR applications, in which adaptive behaviors of artificial agents acting within complex environments have to be simulated.
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paper_title: A Conceptual Framework for Adaptation and Personalization in Virtual Environments

paper_content:

When interacting in a virtual environment, users are confronted with a number of interaction techniques. These interaction techniques may complement each other, but in some circumstances can be used interchangeably. Because of this, it is difficult for the user to determine which interaction technique to use. Furthermore, the use of multimodal feedback, such as haptics and sound, has proven beneficial for some, but not all, users. This complicates the development of such a virtual environment, as the designers are not sure of the implications of the addition of interaction techniques and multimodal feedback.A promising approach for solving these problems lies in the use of adaptation and personalization. By incorporating knowledge of a user’s preferences and habits, the user interface should adapt to the current context of use. This could mean that only a subset of all possible interaction techniques is presented to the user. Alternatively, the interaction techniques themselves could be adapted, e.g. by changing the sensitivity or the nature of the feedback. In this paper, we propose a conceptual framework for realizing adaptive personalized interaction in virtual environments. Furthermore, we discuss how a user model can be built, as this model forms the important first step in implementing the conceptual framework.
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paper_title: A user interface framework for multimodal VR interactions

paper_content:

This article presents a User Interface (UI) framework for multimodal interactions targeted at immersive virtual environments. Its configurable input and gesture processing components provide an advanced behavior graph capable of routing continuous data streams asynchronously. The framework introduces a Knowledge Representation Layer which augments objects of the simulated environment with Semantic Entities as a central object model that bridges and interfaces Virtual Reality (VR) and Artificial Intelligence (AI) representations. Specialized node types use these facilities to implement required processing tasks like gesture detection, preprocessing of the visual scene for multimodal integration, or translation of movements into multimodally initialized gestural interactions. A modified Augmented Transition Nettwork (ATN) approach accesses the knowledge layer as well as the preprocessing components to integrate linguistic, gestural, and context information in parallel. The overall framework emphasizes extensibility, adaptivity and reusability, e.g., by utilizing persistent and interchangeable XML-based formats to describe its processing stages.
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paper_title: Designing transition networks for multimodal VR-interactions using a markup language

paper_content:

This article presents one core component for enabling multimodal-speech and gesture-driven interaction in and for virtual environments. A so-called temporal Augmented Transition Network (tATN) is introduced. It allows to integrate and evaluate information from speech, gesture, and a given application context using a combined syntactic/semantic parse approach. This tATN represents the target structure for a multimodal integration markup language (MIML). MIML centers around the specification of multimodal interactions by letting an application designer declare temporal and semantic relations between given input utterance percepts and certain application states in a declarative and portable manner. A subsequent parse pass translates MIML into corresponding tATNs which are directly loaded and executed by a simulation engines scripting facility.
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paper_title: Input Device Selection and Interaction Configuration with ICON

paper_content:

This paper describes ICON, a novel editor designed to configure a set of input devices and connect them to actions into a graphical interactive application. ICON allows ‘power users’ to customise the way an application manages its input to suit their needs. New configurations can be designed to help physically challenged users to use alternative input methods, or skilled users — graphic designers or musicians for example — to use their favourite input devices and interaction techniques (bimanual, voice enabled, etc.).
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paper_title: Adaptive interaction in Web3D virtual worlds

paper_content:

In recent years a number of techniques have been studied for augmenting the ease of use of 3D worlds: methodologies for adapting both navigation and content allow a user to interact with a customized 3D world; adaptable navigation paradigms offer parallel modalities for different classes of users. In both cases the goal is to reduce the cognitive load needed for interaction.This work focuses on interaction adaptivity, trying to anticipate the user behaviors by monitoring their interaction patterns. Identification of recurring patterns of interaction is used for shortening users interaction when they approach objects belonging to the same class of those ones previously accessed.An agent based approach is used for monitoring the user activity and for proactively adapting interaction: a pair of agents, called numen (bound to the user) and genius loci (associated with the interaction areas called interaction loci) observe and mediate the users' interaction and adapt the 3D world in order to match their needs.The users are always made aware by the system about the changes in the 3D world and they are always in control. They can deactivate adaptiveness for a while, letting the system only to monitor their actions without applying automatically interaction shortcuts. An implementation architecture and a demonstration prototype are presented. A case study related to virtual fairs is examined, discussing a number of adaptive interaction examples.
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paper_title: The Grappl 3D interaction technique library

paper_content:

One of the obstacles to the widespread use of interactive 3D applications is the lack of good tools for developing them. The development of these tools has been complicated by the wide range of hardware configurations used in 3D applications. Also, there is a lack of common software platforms for developing the tools required for 3D user interfaces. As a result, many groups develop their own set of interaction techniques without taking advantage of the work of others, wasting a considerable amount of development time. The Grappl project aims to solve these problems by providing software tools that adapt to the hardware configuration and automatically design most of the user interface. One of the main components of this project is an interaction technique library that supports a wide range of input and output devices. This library provides an open platform for the development of 3D interaction techniques that encourages further development in this area. Interaction techniques developed using this toolkit can be used in our user interface design system, so application developers can easily take advantage of new interaction techniques. The design and implementation of this library is described in this paper.
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paper_title: A layout framework for 3D user interfaces

paper_content:

Two of the main problems facing the developers of 3D user interface are the wide range of device configurations that must be supported and the lack of software tools for constructing 3D user interfaces. The Grappl project aims to solve these problems by producing user interfaces that adapt to the device configurations that they encounter at runtime. Since the user interface is constructed at runtime one of the problems confronted by Grappl is laying out the different user interface components and possibly some of the application objects. This paper presents a framework for automating the layout of 3D user interfaces, including the types of information provided by the user interface designer, the high level architecture of the layout system and the algorithms used for empty space management.
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paper_title: Decimation of triangle meshes

paper_content:

The polygon remains a popular graphics primitive for computer graphics application. Besides having a simple representation, computer rendering of polygons is widely supported by commercial graphics hardware and software. However, because the polygon is linear, often thousands or millions of primitives are required to capture the details of complex geometry. Models of this size are generally not practical since rendering speeds and memory requirements are proportional to the number of polygons. Consequently applications that generate large polygonal meshes often use domain-specific knowledge to reduce model size. There remain algorithms, however, where domainspecific reduction techniques are not generally available or appropriate. One algorithm that generates many polygons is marching cubes. Marching cubes is a brute force surface construction algorithm that extracts isodensity surfaces from volume data, producing from one to five triangles within voxels that contain the surface. Although originally developed for medical applications, marching cubes has found more frequent use in scientific visualization where the size of the volume data sets are much smaller than those found in medical applications. A large computational fluid dynamics volume could have a finite difference grid size of order 100 by 100 by 100, while a typical medical computed tomography or magnetic resonance scanner produces over 100 slices at a resolution of 256 by 256 or 512 by 512 pixels each. Industrial computed tomography, used for inspection and analysis, has even greater resolution, varying from 512 by 512 to 1024 by 1024 pixels. For these sampled data sets, isosurface extraction using marching cubes can produce from 500k to 2,000k triangles. Even today’s graphics workstations have trouble storing and rendering models of this size. Other sampling devices can produce large polygonal models: range cameras, digital elevation data, and satellite data. The sampling resolution of these devices is also improving, resulting in model sizes that rival those obtained from medical scanners. This paper describes an application independent algorithm that uses local operations on geometry and topology to reduce the number of triangles in a triangle mesh. Although our implementation is for the triangle mesh, it can be directly applied to the more general polygon mesh. After describing other work related to model creation from sampled data, we describe the triangle decimation process and its implementation. Results from two different geometric modeling applications illustrate the strengths of the algorithm.
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paper_title: QTk: An Integrated Model-Based Approach to Designing Executable User Interfaces

paper_content:

QTk is a tool built on top of Tcl/Tk that allows user interface designers to adopt a cost-effective model-based approach for designing executable user interfaces. QTk is based on a descriptive approach that uses a declarative style where appropriate (symbolic records to specify widget types, initial states, and geometry management; procedure values to specify actions), augmented with objects and threads to handle the active part of the interface. QTk offers four original advantages: unicity of language (only one language serves as both modeling and programming language), reduced development cost (the interface model immediately gives rise to an executable user interface), tight integration of tools (specification, construction, and execution tools are all integrated), and improved expressiveness (the interface model is very compact to produce and cheap to manipulate). The advantages are made possible by a tight integration with a multiparadigm programming language, Oz, that supports symbolic data structures, a functional programming style, an object programming style, and cheap threads. QTk is a module of the Mozart Programming System, which implements Oz. We show how to port QTk to Java, which allows to retain some but not all of the tool's advantages.
---
paper_title: Information filtering for mobile augmented reality

paper_content:

Augmented reality is a potentially powerful paradigm for annotating the (real) environment with computer-generated material. These benefits will be even greater when augmented reality systems become mobile and wearable. However, to minimize the problem of clutter and to maximize the effectiveness of the display, algorithms must be developed to select only the most important information for the user. In this paper, we describe a region-based information filtering algorithm. The algorithm takes account of the state of the user (location and intent) and the state of individual objects about which information can be presented. It can dynamically respond to changes in the environment and the user's state. We also describe how simple temporal, distance and angle cues can be used to refine the transitions between different information sets.
---
paper_title: A platform for virtual museums with personalized content

paper_content:

Presentation of content is an important aspect of today's virtual reality applications, especially in domains such as virtual museums. The large amount and variety of exhibits in such applications raise a need for adaptation and personalization of the environment. This paper presents a content personalization platform for Virtual Museums, which is based on a semantic description of content and on information implicitly collected about the users through their interactions with the museum. The proposed platform uses stereotypes to initialize user models, adapts user profiles dynamically and clusters users into similar interest groups. A science fiction museum has been set up as a case study for this platform and an evaluation has been carried out.
---
paper_title: ENTER: the personalisation and contextualisation of 3-dimensional worlds

paper_content:

We present the details of the ENTER (Environment which Totally Envelops the useR) system. The ENTER system seeks to provide a totally, immersive 3-dimensional environment which is highly, configurable and personalised based on the perceived needs of an individual user. The use of agent-oriented modelling and design techniques has lead to a versatile and flexible system within which the constituent agents collaborate to realise the system aims. The facility to dynamically reconfigure virtual worlds controlled by the agent entities lends to the technology being applicable for differing immersive environments. This system has in the first instance been cast in the arena of virtual shopping malls, but of course this represents but one potential application domain.
---
paper_title: Dynamic generation of personalized VRML content: a general approach and its application to 3D e-commerce

paper_content:

The capability of (semi)automatically adapting the content, structure, and/or presentation of a Web site to address the interests and preferences of each individual user is more and more considered as a key factor to increase user satisfaction and building customer loyalty. However, while a large body of literature is available about making traditional Web sites adaptive, it is surprising that no research effort has been yet devoted to the problem of adapting Web3D content and presentation. This paper focuses on this topic, proposing a general approach to build adaptive 3D Web sites, and illustrating a specific application of the approach to a 3D e-commerce case study. The architecture we propose, called AWE3D (Adaptive WEb 3D), is based on a combination of readily available and platform-independent Web technologies so that it can be reproduced by interested readers.
---
paper_title: Using the AMACONT architecture for flexible adaptation of 3D web applications

paper_content:

Providing personalized content and applications which also address heterogeneous capabilities of multiple device types becomes a significant challenge of today's Web development. By now most of the work in the field of adaptive hypermedia is devoted to Web content such as hypertext, images, video, and animation, but rarely to three-dimensional graphics. Research on the adaptation of 3D graphics is still in its infancy. The generic approach introduced in this paper combines the AMACONT adaptive hypermedia architecture with the component-based 3D document model CONTIGRA to achieve 3D adaptation methods such as parametric, structural, and implicit rule-based adaptation as well as rich hypermedia adaptation across media boundaries. In addition a layered context modeling framework supports not only personalization, but also adaptation to device and other contexts. It is shown that the approach can be generalized to other XML-based 3D document formats, e.g. X3D.
---
paper_title: Network-Based Visualization of 3D Landscapes and City Models

paper_content:

To improve the visualization of large 3D landscapes and city models in a network environment, the authors use two different types of hierarchical level-of-detail models for terrain and groups of buildings. They also leverage the models to implement progressive streaming in both client-server and peer-to-peer network architectures. Visualizing large photorealistic 3D landscapes and city models has received significant attention over the last 10 years in the computer graphics community. More recently, the availability of broadband Internet access and Web-based visualization techniques is paving the way for large-scale 3D landscapes and city models for a variety of professional and mass-market services. To make such services appealing to a large audience, these 3D models must reach a sufficient level of realism and accuracy. Many solutions are now available to automatically generate 3D models of huge urban environments. Geographic information system (GIS) databases (such as terrain elevation grids, orthophotographs, and a building's footprint and height) provide a good basis for generating such models at affordable cost with minimum human intervention. In the future, the accuracy and realism of 3D city models will be improved thanks to recent progress in data capturing techniques.
---
paper_title: Adaptation mechanism for three dimensional content within the MPEG-21 framework

paper_content:

The goal of the research is creation of an adaptation mechanism for the delivery of three-dimensional content. The adaptation of content, for various network and terminal capabilities - as well as for different user preferences, is a key feature that needs to be investigated. Current state-of-the art research of the adaptation shows promising results for specific purpose and limited types of content but still it is not well adaptable for the massive heterogeneous environments. We present a method for transmitting adapted thee-dimensional contents to multiple target devices. We present some theoretical and practical methods for adapting three-dimensional contents, which includes shapes and animation. We also discuss practical details to the integration of our methods into MPEG-21 and MPEG-4 architectures
---
paper_title: Towards a new generation of widgets for supporting software plasticity: the “comet”

paper_content:

This paper addresses software adaptation to context of use. It goes one step further than our early work on plasticity [5]. Here, we propose a revision of the notion of software plasticity that we apply at the widget level in terms of comets. Plasticity is defined as the ability of an interactive system to withstand variations of context of use while preserving quality in use where quality in use refers to the ISO definition. Plasticity is not limited to the UI components of an interactive system, nor to a single platform: adaptation to context of use may also impact the functional core, it may have an effect on the nature of the connectors, and it may draw upon the existence of multiple platforms in the vicinity to migrate all or portions of the interactive system. A new reference framework that structures the development process of plastic interactive systems is presented to cover these issues. The framework is then applied at the granularity of widgets to provide the notion of a comet. A comet is an introspective widget that is able to self-adapt to some context of use, or that can be adapted by a tier-component to the context of use, or that can be dynamically discarded (versus recruited) when it is unable (versus able) to cover the current context of use. To do so, a comet publishes the quality in use it guarantees, the user tasks and the domain concepts that it is able to support, as well as the extent to which it supports adaptation.
---
paper_title: A layout framework for 3D user interfaces

paper_content:

Two of the main problems facing the developers of 3D user interface are the wide range of device configurations that must be supported and the lack of software tools for constructing 3D user interfaces. The Grappl project aims to solve these problems by producing user interfaces that adapt to the device configurations that they encounter at runtime. Since the user interface is constructed at runtime one of the problems confronted by Grappl is laying out the different user interface components and possibly some of the application objects. This paper presents a framework for automating the layout of 3D user interfaces, including the types of information provided by the user interface designer, the high level architecture of the layout system and the algorithms used for empty space management.
---
paper_title: A flexible framework to personalize 3D web users experience

paper_content:

Nowadays, Web 3D is reaching a new milestone thanks to the convergence of various technologies including new Web standards (such as HTML 5 and WebGL), new device controllers to ease 3D navigation and interaction (Natal Project®, Wiimote®, ...) and home 3D displays. Despite these new factors, the lack of efficient and high level authoring tools to ease the creation and reduce the production cost of Web 3D interfaces is still a strong impediment to the large scale use of Web 3D contents. In this article, we present a framework based on current websites design pipeline that is distinguished by content management, graphic charter design and interface design. Moreover, our solution must reach a sufficient level of flexibility in terms of extensibility, of modularity, of genericity of input and output file formats, as well as of range of interfaces potentially feasible by designers. Thus we propose a software environment allowing metaphor-based information presentation, taking into consideration both the data structure (how the user explores and discovers data) and the visual aspect of the computed environment (the geometry and data representation). These metaphors may be used to visualize large volumes of information coming from databases or classic/semantic search results. The created environments may be highly varying, from 3D interfaces to 3D worlds inside which the user can navigate with an avatar and interact with other users. Various examples are given to illustrate the flexibility of the technique.
---
paper_title: QTk: An Integrated Model-Based Approach to Designing Executable User Interfaces

paper_content:

QTk is a tool built on top of Tcl/Tk that allows user interface designers to adopt a cost-effective model-based approach for designing executable user interfaces. QTk is based on a descriptive approach that uses a declarative style where appropriate (symbolic records to specify widget types, initial states, and geometry management; procedure values to specify actions), augmented with objects and threads to handle the active part of the interface. QTk offers four original advantages: unicity of language (only one language serves as both modeling and programming language), reduced development cost (the interface model immediately gives rise to an executable user interface), tight integration of tools (specification, construction, and execution tools are all integrated), and improved expressiveness (the interface model is very compact to produce and cheap to manipulate). The advantages are made possible by a tight integration with a multiparadigm programming language, Oz, that supports symbolic data structures, a functional programming style, an object programming style, and cheap threads. QTk is a module of the Mozart Programming System, which implements Oz. We show how to port QTk to Java, which allows to retain some but not all of the tool's advantages.
---
paper_title: An open software architecture for virtual reality interaction

paper_content:

This article describes OpenTracker, an open software architecture that provides a framework for the different tasks involved in tracking input devices and processing multi-modal input data in virtual environments and augmented reality application. The OpenTracker framework eases the development and maintenance of hardware setups in a more flexible manner than what is typically offered by virtual reality development packages. This goal is achieved by using an object-oriented design based on XML, taking full advantage of this new technology by allowing to use standard XML tools for development, configuration and documentation. The OpenTracker engine is based on a data flow concept for multi-modal events. A multi-threaded execution model takes care of tunable performance. Transparent network access allows easy development of decoupled simulation models. Finally, the application developer's interface features both a time-based and an event based model, that can be used simultaneously, to serve a large range of applications. OpenTracker is a first attempt towards a "'write once, input anywhere"' approach to virtual reality application development. To support these claims, integration into an existing augmented reality system is demonstrated. We also show how a prototype tracking equipment for mobile augmented reality can be assembled from consumer input devices with the aid of OpenTracker. Once development is sufficiently mature, it is planned to make Open-Tracker available to the public under an open source software license.
---
paper_title: VRPN: a device-independent, network-transparent VR peripheral system

paper_content:

The Virtual-Reality Peripheral Network (VRPN) system provides a device-independent and network-transparent interface to virtual-reality peripherals. VRPN's application of factoring by function and of layering in the context of devices produces an interface that is novel and powerful. VRPN also integrates a wide range of known advanced techniques into a publicly-available system. These techniques benefit both direct VRPN users and those who implement other applications that make use of VR peripherals.
---
paper_title: A migration mechanism to manage network troubles while interacting within collaborative virtual environments

paper_content:

Real time collaborative interactions within CVEs rely on the low latency offered by high speed networks. When low level network troubles occur during a collaborative session, participants of networked collaborative virtual environments can suffer from misunderstanding weird behavior of some objects of the virtual universe. We want to make such a virtual world easier to understand by using some graphic visualizations in such a way that the users become aware of these problems. It is a kind of augmentation of the Virtual Environment thanks to dedicated 3D metaphors associated to some objects of the virtual environment. We also want to allow users to work while these troubles occur, maybe with only restricted interaction possibilities, by making some interactive objects migrate onto the same site than the user who wants to interact with them. This is why we present then how two independent mechanisms may be coupled together for a better management and awareness of network troubles while interacting within a networked collaborative virtual environment: an awareness system that visualizes, through special metaphors, the existence of a network trouble as strong delay or disconnection; and a virtual object migration system that allows the migration of an object from one site to another to ensure a non interrupted manipulation in case of network troubles.
---
paper_title: Dynamic generation of personalized VRML content: a general approach and its application to 3D e-commerce

paper_content:

The capability of (semi)automatically adapting the content, structure, and/or presentation of a Web site to address the interests and preferences of each individual user is more and more considered as a key factor to increase user satisfaction and building customer loyalty. However, while a large body of literature is available about making traditional Web sites adaptive, it is surprising that no research effort has been yet devoted to the problem of adapting Web3D content and presentation. This paper focuses on this topic, proposing a general approach to build adaptive 3D Web sites, and illustrating a specific application of the approach to a 3D e-commerce case study. The architecture we propose, called AWE3D (Adaptive WEb 3D), is based on a combination of readily available and platform-independent Web technologies so that it can be reproduced by interested readers.
---
paper_title: Using the AMACONT architecture for flexible adaptation of 3D web applications

paper_content:

Providing personalized content and applications which also address heterogeneous capabilities of multiple device types becomes a significant challenge of today's Web development. By now most of the work in the field of adaptive hypermedia is devoted to Web content such as hypertext, images, video, and animation, but rarely to three-dimensional graphics. Research on the adaptation of 3D graphics is still in its infancy. The generic approach introduced in this paper combines the AMACONT adaptive hypermedia architecture with the component-based 3D document model CONTIGRA to achieve 3D adaptation methods such as parametric, structural, and implicit rule-based adaptation as well as rich hypermedia adaptation across media boundaries. In addition a layered context modeling framework supports not only personalization, but also adaptation to device and other contexts. It is shown that the approach can be generalized to other XML-based 3D document formats, e.g. X3D.
---
paper_title: Viargo - A generic virtual reality interaction library

paper_content:

Traditionally, interaction techniques for virtual reality applications are implemented in a proprietary way on specific target platforms, e. g., requiring specific hardware, physics or rendering libraries, which withholds reusability and portability. Though hardware abstraction layers for numerous devices are provided by multiple virtual reality libraries, they are usually tightly bound to a particular rendering environment. In this paper we introduce Viargo - a generic virtual reality interaction library, which serves as additional software layer that is independent from the application and its linked libraries, i. e., a once developed interaction technique, such as walking with a head-mounted display or multi-touch interaction, can be ported to different hard- or software environments with minimal code adaptation. We describe the underlying concepts and present examples on how to integrate Viargo in different graphics engines, thus extending proprietary graphics libraries with a few lines of code to easy-to-use virtual reality engines.
---
paper_title: AMACONT: A System Architecture for Adaptive Multimedia Web Applications

paper_content:

Engineering personalized ubiquitous Web applications requires to develop adaptable Web content as well as to automatically adjust it to varying client devices and dynamically changing user preferences. To meet this requirement, this paper introduces the system architecture of the AMACONT project [Am04] that aims at the dynamic generation of Web presentations tailored to users’ varying needs and device capabilities. Different techniques for static and dynamic content, layout and structure adaptation supported by the overall architecture are explained. Furthermore, strategies for dynamic device and user modeling are illustrated in order to guarantee up-to-date user and device models for the whole content generation process. Finally, modules of a modular graphical authoring tool for the visual development of adaptive Web applications are presented.
---
paper_title: Plastic User Interfaces: Designing for Change

paper_content:

Everybody knows that mobile computing provides us with tremendous versatility. But this versatility also increases in a great deal the complexity in the design of User Interfaces (UI). It is obvious the necessity of an architectural framework that provides dynamic adaptation. We propose a reflective architecture to manage the system to adjust its own behaviour according to certain runtime conditions, related to the context of use. The benefits of reflection are, apart from dynamic adaptation, transparency and reusability. We also present the underlying plastic UIs development framework, inspired in the model-based approach . Its focus of attention is also to solve contextual changes, as one of the most important lacks detected in literature.
---
paper_title: An open software architecture for virtual reality interaction

paper_content:

This article describes OpenTracker, an open software architecture that provides a framework for the different tasks involved in tracking input devices and processing multi-modal input data in virtual environments and augmented reality application. The OpenTracker framework eases the development and maintenance of hardware setups in a more flexible manner than what is typically offered by virtual reality development packages. This goal is achieved by using an object-oriented design based on XML, taking full advantage of this new technology by allowing to use standard XML tools for development, configuration and documentation. The OpenTracker engine is based on a data flow concept for multi-modal events. A multi-threaded execution model takes care of tunable performance. Transparent network access allows easy development of decoupled simulation models. Finally, the application developer's interface features both a time-based and an event based model, that can be used simultaneously, to serve a large range of applications. OpenTracker is a first attempt towards a "'write once, input anywhere"' approach to virtual reality application development. To support these claims, integration into an existing augmented reality system is demonstrated. We also show how a prototype tracking equipment for mobile augmented reality can be assembled from consumer input devices with the aid of OpenTracker. Once development is sufficiently mature, it is planned to make Open-Tracker available to the public under an open source software license.
---
paper_title: VRPN: a device-independent, network-transparent VR peripheral system

paper_content:

The Virtual-Reality Peripheral Network (VRPN) system provides a device-independent and network-transparent interface to virtual-reality peripherals. VRPN's application of factoring by function and of layering in the context of devices produces an interface that is novel and powerful. VRPN also integrates a wide range of known advanced techniques into a publicly-available system. These techniques benefit both direct VRPN users and those who implement other applications that make use of VR peripherals.
---
paper_title: Input Device Selection and Interaction Configuration with ICON

paper_content:

This paper describes ICON, a novel editor designed to configure a set of input devices and connect them to actions into a graphical interactive application. ICON allows ‘power users’ to customise the way an application manages its input to suit their needs. New configurations can be designed to help physically challenged users to use alternative input methods, or skilled users — graphic designers or musicians for example — to use their favourite input devices and interaction techniques (bimanual, voice enabled, etc.).
---
paper_title: Plasticity of User Interfaces: Framework and Research Agenda

paper_content:

This paper introduces the notion of plasticity, a new property of interactive systems that denotes a particular type of user interface adaptation. Plasticity is the capacity of a user interface to withstand variations of both the system physical characteristics and the environment while preserving usability. Typically, a ‘plastic’ electronic agenda would run both on a workstation and on a hand-held computer without requiring a complete system redesign and re-implementation. We present a generic framework inspired by the model-based approach, for supporting the development of plastic user interfaces. Within this framework, a plastic user interface is specified once and serves multiple sources of physical variations. The goal is to guarantee usability continuity under variations in physical constraints while minimizing development and maintenance costs. This framework is illustrated with two simple case studies. Preliminary results and the state of the art in HCI open a new research agenda for the design and development of plastic user interfaces.
---
paper_title: Using the AMACONT architecture for flexible adaptation of 3D web applications

paper_content:

Providing personalized content and applications which also address heterogeneous capabilities of multiple device types becomes a significant challenge of today's Web development. By now most of the work in the field of adaptive hypermedia is devoted to Web content such as hypertext, images, video, and animation, but rarely to three-dimensional graphics. Research on the adaptation of 3D graphics is still in its infancy. The generic approach introduced in this paper combines the AMACONT adaptive hypermedia architecture with the component-based 3D document model CONTIGRA to achieve 3D adaptation methods such as parametric, structural, and implicit rule-based adaptation as well as rich hypermedia adaptation across media boundaries. In addition a layered context modeling framework supports not only personalization, but also adaptation to device and other contexts. It is shown that the approach can be generalized to other XML-based 3D document formats, e.g. X3D.
---
paper_title: DEVAL: a device abstraction layer for VR/AR

paper_content:

While software developers for desktop applications can rely on mouse and keyboard as standard input devices, developers of virtual reality (VR) and augmented reality (AR) applications usually have to deal with a large variety of individual interaction devices. Existing device abstraction layers provide a solution to this problem, but are usually limited to a specific set or type of input devices. In this paper we introduce DEVAL - an approach to a device abstraction layer for VR and AR applications. DEVAL is based on a device hierarchy that is not limited to input devices, but naturally extends to output devices.
---
paper_title: The Grappl 3D interaction technique library

paper_content:

One of the obstacles to the widespread use of interactive 3D applications is the lack of good tools for developing them. The development of these tools has been complicated by the wide range of hardware configurations used in 3D applications. Also, there is a lack of common software platforms for developing the tools required for 3D user interfaces. As a result, many groups develop their own set of interaction techniques without taking advantage of the work of others, wasting a considerable amount of development time. The Grappl project aims to solve these problems by providing software tools that adapt to the hardware configuration and automatically design most of the user interface. One of the main components of this project is an interaction technique library that supports a wide range of input and output devices. This library provides an open platform for the development of 3D interaction techniques that encourages further development in this area. Interaction techniques developed using this toolkit can be used in our user interface design system, so application developers can easily take advantage of new interaction techniques. The design and implementation of this library is described in this paper.
---
paper_title: 3D Interaction Assistance in Virtual Reality: A Semantic Reasoning Engine for Context-Awareness

paper_content:

This work focuses on 3D interaction assistance by adding adaptivity depending on the tasks, the objectives, and the general interaction context. An engine to reach context-awareness has been implemented in Prolog+CG which uses Conceptual Graphs (CGs) based on an ontology. CGs descriptions of the available sensors and actuators in our scene manager (Virtools) allow the engine to take decisions and send them through Open Sound Control (OSC). Measurements and adaptations corresponding to specific tools uses are decided from rules handled by the engine. This project is a step towards Intelligent Virtual Environments, which proposes a hybrid solution by adding a separate semantic reasoning to classic environments. The first experiment automatically manages few modalities depending on the distance to objects, user movement, available tools, etc. Gestures are used both as an engine direct control and as an interpretation of user activity.
---
paper_title: AdapTIVE: an intelligent virtual environment and its application in e-commerce

paper_content:

This work presents an intelligent virtual environment, called AdapTIVE (adaptive three-dimensional intelligent and virtual environment), which has its structure and presentation customized according to users' interests and preferences (represented in a user model) and in accordance with insertion and removal of contents in this environment. An automatic content categorization process is applied to create content models, used in the spatial organization of the contents in the environment. An intelligent agent assists users during navigation in the environment and retrieval of relevant information. This is a promising approach for new and advanced forms of education, entertainment and e-commerce. In order to validate our approach, a case study of an e-commerce environment is presented.
---
paper_title: A Conceptual Framework for Adaptation and Personalization in Virtual Environments

paper_content:

When interacting in a virtual environment, users are confronted with a number of interaction techniques. These interaction techniques may complement each other, but in some circumstances can be used interchangeably. Because of this, it is difficult for the user to determine which interaction technique to use. Furthermore, the use of multimodal feedback, such as haptics and sound, has proven beneficial for some, but not all, users. This complicates the development of such a virtual environment, as the designers are not sure of the implications of the addition of interaction techniques and multimodal feedback.A promising approach for solving these problems lies in the use of adaptation and personalization. By incorporating knowledge of a user’s preferences and habits, the user interface should adapt to the current context of use. This could mean that only a subset of all possible interaction techniques is presented to the user. Alternatively, the interaction techniques themselves could be adapted, e.g. by changing the sensitivity or the nature of the feedback. In this paper, we propose a conceptual framework for realizing adaptive personalized interaction in virtual environments. Furthermore, we discuss how a user model can be built, as this model forms the important first step in implementing the conceptual framework.
---
paper_title: Sto(ry)chastics: A Bayesian Network Architecture for User Modeling and Compuatational Storytelling for Interactive Spaces

paper_content:

This paper presents sto(ry)chastics, a user-centered approach for computational storytelling for real-time sensor-driven multimedia audiovisual stories, such as those that are triggered by the body in motion in a sensor-instrumented interactive narrative space. With sto(ry)chastics the coarse and noisy sensor inputs are coupled to digital media outputs via a user model, which is estimated probabilistically by a Bayesian network. To illustrate sto(ry)chastics, this paper describes the museum wearable, a device which delivers an audiovisual narration interactively in time and space to the visitor as a function of the estimated visitor type. The wearable relies on a custom-designed long-range infrared location-identification sensor to gather information on where and how long the visitor stops in the museum galleries and uses this information as input to, or observations of, a (dynamic) Bayesian network. The network has been tested and validated on observed visitor tracking data by parameter learning using the Expectation Maximization (EM) algorithm, and by performance analysis of the model with the learned parameters.
---
paper_title: A platform for virtual museums with personalized content

paper_content:

Presentation of content is an important aspect of today's virtual reality applications, especially in domains such as virtual museums. The large amount and variety of exhibits in such applications raise a need for adaptation and personalization of the environment. This paper presents a content personalization platform for Virtual Museums, which is based on a semantic description of content and on information implicitly collected about the users through their interactions with the museum. The proposed platform uses stereotypes to initialize user models, adapts user profiles dynamically and clusters users into similar interest groups. A science fiction museum has been set up as a case study for this platform and an evaluation has been carried out.
---
paper_title: ENTER: the personalisation and contextualisation of 3-dimensional worlds

paper_content:

We present the details of the ENTER (Environment which Totally Envelops the useR) system. The ENTER system seeks to provide a totally, immersive 3-dimensional environment which is highly, configurable and personalised based on the perceived needs of an individual user. The use of agent-oriented modelling and design techniques has lead to a versatile and flexible system within which the constituent agents collaborate to realise the system aims. The facility to dynamically reconfigure virtual worlds controlled by the agent entities lends to the technology being applicable for differing immersive environments. This system has in the first instance been cast in the arena of virtual shopping malls, but of course this represents but one potential application domain.
---
paper_title: A User-Adaptive Interface Agency for Interaction With Virtual Environment

paper_content:

This paper describes an approach to user adaptation realized in a multiagent interface system for interaction with a virtual environment. The interface agency adapts to users' individual preferences by learning from direct feedback. The core idea is that agents that were successful in meeting the user's expectations are given credit while unsuccessful agents are “discredited.” Communicating credit values, agents organize themselves so that the overall behavior of the interface agency gradually adapts to the individual user as the session is proceeding.
---
paper_title: Dynamic generation of personalized VRML content: a general approach and its application to 3D e-commerce

paper_content:

The capability of (semi)automatically adapting the content, structure, and/or presentation of a Web site to address the interests and preferences of each individual user is more and more considered as a key factor to increase user satisfaction and building customer loyalty. However, while a large body of literature is available about making traditional Web sites adaptive, it is surprising that no research effort has been yet devoted to the problem of adapting Web3D content and presentation. This paper focuses on this topic, proposing a general approach to build adaptive 3D Web sites, and illustrating a specific application of the approach to a 3D e-commerce case study. The architecture we propose, called AWE3D (Adaptive WEb 3D), is based on a combination of readily available and platform-independent Web technologies so that it can be reproduced by interested readers.
---
paper_title: Using the AMACONT architecture for flexible adaptation of 3D web applications

paper_content:

Providing personalized content and applications which also address heterogeneous capabilities of multiple device types becomes a significant challenge of today's Web development. By now most of the work in the field of adaptive hypermedia is devoted to Web content such as hypertext, images, video, and animation, but rarely to three-dimensional graphics. Research on the adaptation of 3D graphics is still in its infancy. The generic approach introduced in this paper combines the AMACONT adaptive hypermedia architecture with the component-based 3D document model CONTIGRA to achieve 3D adaptation methods such as parametric, structural, and implicit rule-based adaptation as well as rich hypermedia adaptation across media boundaries. In addition a layered context modeling framework supports not only personalization, but also adaptation to device and other contexts. It is shown that the approach can be generalized to other XML-based 3D document formats, e.g. X3D.
---
paper_title: Semantic-based rules for 3D scene adaptation

paper_content:

3D data is democratizing on the Web as it becomes available to everybody on almost all access devices. Still, 3D data is a heavy medium, as it contains a lot of geometric and texture information. This complexity raises a lot of problems, especially when data initially designed for great capacity access devices, is to be deployed on small devices. Due to the great heterogeneity of access devices and of their users and usages, the adaptation of already designed data is an important issue. In this paper, we present a rule-based adaptation framework that deals with the adaptation of X3D scenes. An adaptation rule indicates a type of adaptation to be applied to a set of objects which fit with the rule criterion. A basic set of adaptation techniques are registered within the framework. The framework is flexible and additional adaptation engines can be registered in order to support large sets of adaptation techniques.
---
paper_title: Information filtering for mobile augmented reality

paper_content:

Augmented reality is a potentially powerful paradigm for annotating the (real) environment with computer-generated material. These benefits will be even greater when augmented reality systems become mobile and wearable. However, to minimize the problem of clutter and to maximize the effectiveness of the display, algorithms must be developed to select only the most important information for the user. In this paper, we describe a region-based information filtering algorithm. The algorithm takes account of the state of the user (location and intent) and the state of individual objects about which information can be presented. It can dynamically respond to changes in the environment and the user's state. We also describe how simple temporal, distance and angle cues can be used to refine the transitions between different information sets.
---
paper_title: The MORGAN framework: enabling dynamic multi-user AR and VR projects

paper_content:

The availability of a suitable framework is of vital importance for the development of Augmented Reality (AR) and Virtual Reality (VR) projects. While features such as scalability, platform independence, support of multiple users, distribution of components, and an efficient and sophisticated rendering are the key requirements of current and future applications, existing frameworks often address these issues only partially. In our paper we present MORGAN --- an extensible component-based AR/VR framework, enabling sophisticated dynamic multi-user AR and VR projects. Core components include the MORGAN API, providing developers access to various input devices, including common tracking devices, as well as a modular render engine concept, allowing us to provide native support for individual scene graph concepts. The MORGAN framework has already been successfully deployed in several national and international research and development projects.
---
paper_title: Using the AMACONT architecture for flexible adaptation of 3D web applications

paper_content:

Providing personalized content and applications which also address heterogeneous capabilities of multiple device types becomes a significant challenge of today's Web development. By now most of the work in the field of adaptive hypermedia is devoted to Web content such as hypertext, images, video, and animation, but rarely to three-dimensional graphics. Research on the adaptation of 3D graphics is still in its infancy. The generic approach introduced in this paper combines the AMACONT adaptive hypermedia architecture with the component-based 3D document model CONTIGRA to achieve 3D adaptation methods such as parametric, structural, and implicit rule-based adaptation as well as rich hypermedia adaptation across media boundaries. In addition a layered context modeling framework supports not only personalization, but also adaptation to device and other contexts. It is shown that the approach can be generalized to other XML-based 3D document formats, e.g. X3D.
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Title: A Survey of Plasticity in 3D User Interfaces

Section 1: INTRODUCTION
Description 1: Provide an overview of the increasing interest and distinct characteristics of 3D user interfaces, and introduce the concept of plastic or adaptive 3D user interfaces.

Section 2: CONTEXT
Description 2: Detail the actual state of the plasticity concept, and classify plasticity issues into three parts: adaptation sources, adaptation targets, and the adaptation temporal dimension.

Section 3: Definitions
Description 3: Introduce definitions of plasticity and related fields, and discuss how plasticity is modeled on adaptation sources, adaptation targets, and the temporal dimension.

Section 4: Adaptation sources
Description 4: Explain entities for which adaptation is intended, including hardware, users, and semantic, and how these properties must be modeled and made available to the adaptation mechanism.

Section 5: Adaptation to hardware
Description 5: Discuss the wide variety of platforms and devices on which 3D applications can be run, including input and output devices and their characteristics.

Section 6: Adaptation to the user or to the users (in case of collaboration)
Description 6: Discuss personalization based on user modeling and context, which includes characteristics such as preferences, location, and environment.

Section 7: Adaptation to the semantic
Description 7: Discuss how the semantic of application data can be modeled and used as a source of automatic adaptation.

Section 8: Adaptation targets
Description 8: Classify adaptation targets into interaction techniques modification, content adaptation, and redistribution, and explain how adaptation is performed on these targets.

Section 9: Interaction techniques modification
Description 9: Explain the different types of interaction techniques and how they can be adapted based on the context.

Section 10: Content adaptation
Description 10: Discuss how the content of the system, including intrinsic parameters, quality, and structure, can be adapted.

Section 11: Redistribution
Description 11: Discuss the concept of migrating a part or the whole application across different devices as an adaptation mechanism.

Section 12: Temporal dimension
Description 12: Explain the importance of the temporal dimension in adaptations, distinguishing between static and dynamic adaptations, and their impact on user experience.

Section 13: SOLUTIONS
Description 13: Provide a review of solutions in the literature that handle plasticity, classified into hardware adaptation, user adaptation, and semantic adaptation, and their respective implementation approaches.

Section 14: Hardware adaptation
Description 14: Detail solutions that facilitate hardware adaptation by abstracting device complexities and adapting to various input and output devices.

Section 15: User adaptation
Description 15: Discuss solutions for personalizing applications based on user profiles and context, and various methods such as rule-based and rating systems.

Section 16: Semantic adaptation
Description 16: Explore solutions that model and use data semantics for adapting user interfaces, including rating systems and rule-based methods.

Section 17: DISCUSSION
Description 17: Summarize the survey findings, highlighting the variety and limitations of existing solutions, and identifying domains less explored, such as collaboration and redistribution.

Section 18: CONCLUSION
Description 18: Reinforce the importance of plasticity, summarizing current techniques and the need for a unified solution that addresses all aspects of plasticity for 3D user interfaces.

Section 19: FUTURE WORK
Description 19: Outline the potential directions for future research to develop generic and scalable methods for all adaptation issues, focusing on collaboration, semantic modeling, and providing user-friendly authoring tools.