Roberto Ranon

Web3D technologies in learning, education and training: Motivations, issues, opportunities

Web3D open standards allow the delivery of interactive 3D virtual learning environments through the Internet, reaching potentially large numbers of learners worldwide, at any time. This paper introduces the educational use of virtual reality based on Web3D technologies. After briefly presenting the main Web3D technologies, we summarize the pedagogical basis that motivate their exploitation in the context of education and highlight their interesting features. We outline the main positive and negative results obtained so far, and point out some of the current research directions.

Hierarchical model-based diagnosis based on structural abstraction

Abstraction has been advocated as one of the main remedies for the computational complexity of model-based diagnosis. However, after the seminal work published in the early nineties, little research has been devoted to this topic. In this paper, we consider one of the types of abstraction commonly used in diagnosis, i.e., structural abstraction, investigating it both from a theoretical and practical point of view. First, we provide a new formalization for structural abstraction that generalizes and extends previous ones. Then, we present two new different techniques for model-based diagnosis that automatically derive easier-to-diagnose versions of a (hierarchical) diagnosis problem on the basis of the available observations. The two proposed techniques are formulated as extensions of the well-known Mozetics algorithm [I. Mozetic, Hierarchical diagnosis, in: W.H.L. Console, J. de Kleer (Eds.), Readings in Model-Based Diagnosis, Morgan Kaufmann, San Mateo, CA, 1992, pp. 354-372], and experimentally contrasted with it to evaluate the obtained efficiency gains.

VU-Flow: A Visualization Tool for Analyzing Navigation in Virtual Environments

This paper presents a tool for the visual analysis of navigation patterns of moving entities, such as users, virtual characters or vehicles in 3D virtual environments (VEs). The tool, called VU-Flow, provides a set of interactive visualizations that highlight interesting navigation behaviors of single or groups of moving entities that were the VE together or separately. The visualizations help to improve the design of VEs and to study the navigation behavior of users, e.g., during controlled experiments. Besides VEs, the proposed techniques could also be applied to visualize real-world data recorded by positioning systems, allowing one to employ VU-Flow in domains such as urban planning, transportation, and emergency response

Guiding visitors of Web3D worlds through automatically generated tours

Many Web3D sites do not offer sufficient assistance to (especially novice) users in navigating the virtual world, find objects/places of interests, and learn how to interact with them. This paper aims at helping the Web3D content creator to face this problem by: (i) proposing the adoption of guided tours of virtual worlds as an effective user aid and (ii) describing a novel tool that provides automatic code generation for adding such guided tours to VRML worlds. Finally, we will show how the tool has been used in the development of an application concerning a 3D computer science museum.

Dynamic generation of personalized VRML content: a general approach and its application to 3D e-commerce

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.

Adding Adaptive Features to Virtual Reality Interfaces for E-Commerce

Virtual Reality (VR) interfaces to e-commerce sites have recently begun to appear on the Internet, promising to make the e-shopping experience more natural, attractive, and fun for customers. Adaptivity is an important issue for these VR applications, because it would make them suitable for the 1-to-1 e-commerce strategies towards which sellers are increasingly driven. It is thus surprising that the introduction of adaptive features in VR stores remains a completely unexplored issue. This paper begins to face the problem, presenting and discussing ADVIRT, a first prototype of an adaptive VR store. In ADVIRT, a set of personalization rules exploits a model of the customer to adapt features of the VR store such as: (i) the display of different products in the store (e.g., shelf space, display spots, banners, audio advertising), (ii) the navigation aids available to the customer, (iii) the store layout, organization, and look.

Serious Games for Training Occupants of a Building in Personal Fire Safety Skills

To survive a fire, occupants of a building have to be able to evacuate the structure before the situation becomes unsustainable. Evacuation time is thus a critical factor, but lack of knowledge about the basics of fire safety can dangerously increase this time and also result in various forms of unsafe behavior. In this paper, we propose serious games as a tool to acquire personal fire safety skills, also discussing a specific game we have developed.

Adaptation of Graphics and Gameplay in Fitness Games by Exploiting Motion and Physiological Sensors

Obesity and lack of physical fitness are increasingly common in adults as well as children and can negatively affect health. Regular physical activity, such as jogging or training in a fitness center, is recommended by physiologists to fight obesity and improve ones fitness, but usually requires considerable motivation. Recently, researchers as well as companies have proposed a few fitness games, i.e. videogames where users play by performing physical exercises, in which game elements (such as graphics and gameplay) are used to encourage people to exercise regularly. This paper proposes a fitness game system which aims at combining arcade-style game graphics, physiological sensors (e.g. heart rate monitor, 3D accelerometer), and an adaptation engine. The adaptation engine considers personal information provided by the user (e.g., age and gender), her current heart rate and movements, and information collected during previous game sessions to adjust the required intensity of physical exercises through context-aware and user-adaptive dynamic adaptations of graphics and gameplay. Besides describing the general system, the paper presents two implemented games and a preliminary user evaluation, which also led us to introduce in the system a 3D virtual human.

The director's lens: an intelligent assistant for virtual cinematography

We present the Directors Lens, an intelligent interactive assistant for crafting virtual cinematography using a motion-tracked hand-held device that can be aimed like a real camera. The system employs an intelligent cinematography engine that can compute, at the request of the filmmaker, a set of suitable camera placements for starting a shot. These suggestions represent semantically and cinematically distinct choices for visualizing the current narrative. In computing suggestions, the system considers established cinema conventions of continuity and composition along with the filmmakers previous selected suggestions, and also his or her manually crafted camera compositions, by a machine learning component that adapts shot editing preferences from user-created camera edits. The result is a novel workflow based on interactive collaboration of human creativity with automated intelligence that enables efficient exploration of a wide range of cinematographic possibilities, and rapid production of computer-generated animated movies.

Adaptive Hypermedia Techniques for 3D Educational Virtual Environments

Based on a well-known adaptive hypermedia framework, the proposed system creates a 3D educational virtual environment that selects and personalizes interactive learning content for users. In EVEs, users not only see concepts visualized, but they can perform tasks in a suitable fictional world or a real-world reproduction. Moreover, compared to 2D multimedia, using interactive 3D graphics lets developers create representations of subjects or phenomena that are more informative and make it possible for users to analyze a single subject from different viewpoints. In EVEs, adaptivity can play an important role in increasing both learning-process effectiveness and interface usability.