Lucio Ieronutti

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

Employing virtual humans for education and training in X3D/VRML worlds

Web-based education and training provides a new paradigm for imparting knowledge; students can access the learning material anytime by operating remotely from any location. Web3D open standards, such as X3D and VRML, support Web-based delivery of Educational Virtual Environments (EVEs). EVEs have a great potential for learning and training purposes, by allowing one to circumvent physical, safety, and cost constraints. Unfortunately, EVEs often leave to the user the onus of taking the initiative both in exploring the environment and interacting with its parts. A possible solution to this problem is the exploitation of virtual humans acting as informal coaches or more formal instructors. For example, virtual humans can be employed to show and explain maintenance procedures, allowing learners to receive more practical explanations which are easier to understand. However, virtual humans are rarely used in Web3D EVEs, since the programming effort to develop and re-use them in different environments can be considerable. In this paper, we present a general architecture that allows content creators to easily integrate virtual humans into Web3D EVEs. To test the generality of our solution, we present two practical examples showing how the proposed architecture has been used in different educational contexts.

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.

A virtual human architecture that integrates kinematic, physical and behavioral aspects to control H-Anim characters

Virtual humans are being increasingly used in different domains. Virtual human modeling requires to consider aspects belonging to different levels of abstractions. For example, at lower levels, one has to consider aspects concerning the geometric definition of the virtual human model and appearance while, at higher levels, one should be able to define how the virtual human behaves into an environment. H-Anim, the standard for representing humanoids in X3D/VRML worlds, is mainly concerned with low-level modeling aspects. As a result, the developer has to face the problem of defining the virtual human behavior and translating it into lower levels (e.g. geometrical and kinematic aspects). In this paper, we propose VHA (Virtual Human Architecture), a software architecture that allows one to easily manage an interactive H-Anim virtual human into X3D/VRML worlds. The proposed solution allows the developer to focus mainly on high-level aspects of the modeling process, such as the definition of the virtual human behavior.

CAST: A Novel Trajectory Clustering and Visualization Tool for Spatio-Temporal Data

This paper presents a novel technique for clustering and visualizing spatio-temporal data to analyze the navigational behavior of moving entities, such as users, virtual characters or vehicles. For testing our proposal, we developed CAST (Clustering And visualization tool for Spatio-Temporal data), a tool designed for interactively studying moving entities navigating through real as well as virtual environments. Such analysis allows one to derive information at a level of abstraction suitable to support (i) the evaluation of user spaces and (ii) the identification of the predominant navigation behavior of users. We demonstrate the effectiveness of our solution by testing the tool on data acquired by recording the movements of users while navigating through a virtual environment.

Mobrex: Visualizing Users' Mobile Browsing Behaviors

This paper deals with the Mobile Browsing Explorer (Mobrex) to give analysts a set of interactive visualizations that highlight various aspects of how users browse an information space. Here, we describe the tool and demonstrate its support of a user study of three browsing techniques for mobile maps. Although we mainly focus here on PDAs and mobile map browsing, Mobrex can easily support analysts studying user interaction with other information spaces and other devices, including mobile phones and desktop computers.

Supporting presentation techniques based on virtual humans in educational virtual worlds

Educational virtual worlds (EVWs) allow one to circumvent physical, safety, and cost constraints that often affect real-world training and learning scenarios. Virtual humans can improve the effectiveness of an EVW e.g., by explaining and demonstrating to the user procedural tasks and communicating with learners in a natural way by exploiting both verbal and nonverbal communication. However, choosing how the learning material has to be presented to the learner and how to employ the virtual human is influenced by different factors, ranging from available technology (e.g., bandwidth, graphics hardware, installed software) to learners profile (e.g., physical and/or cognitive disabilities, spatial abilities, 2D/3D navigation expertise). The system we present in this paper flexibly supports different presentation techniques employing a virtual human into an EVW. The different capabilities of the system are illustrated, motivated and discussed

A Methodology Supporting the Design and Evaluating the Final Quality of Data Warehouses

The design and configuration of a data warehouse can be difficult tasks especially in the case of very large databases and in the presence of redundant information. In particular, the choice of which attributes have to be considered as dimensions and measures can be not trivial and it can heavily influence the effectiveness of the final system. In this article, we propose a methodology targeted at supporting the design and deriving information on the total quality of the final data warehouse. We tested our proposal on three real-word commercial ERP databases.

VEX-CMS: a tool to design virtual exhibitions and walkthroughs that integrates automatic camera control capabilities

This paper presents VEX-CMS, a tool to build 3D virtual museums and exhibitions, architectural walkthroughs and, more generally, applications where 3D and 2D content is presented to the user inside a 3D Virtual Environment. In this paper, we concentrate on the task of designing tours of the virtual environment to be followed by visitors, either through manual or automatic navigation, and show how a recent automatic camera control approach [3], coupled with path planning, can be exploited to accomplish the task with minimal knowledge and manual effort on the curators side.

High-level visualization of users' navigation in virtual environments

This paper presents the current status of VU-Flow (Visualization of Users’ Flow), a software tool that is able to automatically record usage data in Virtual Environments and provide a set of 2D and 3D visualizations that make it easy for an evaluator to visually detect peculiar users’ behaviors and navigability problems. The paper focuses on novel functionalities we recently added to the tool. More specifically, the new version of VU-Flow includes: (i) the possibility of visualizing predominant flow directions for multiple users or multiple visiting sessions, (ii) a visualization aimed at highlighting traffic congestion problems in multi-user VEs, (iii) the possibility of visualizing a replay of users’ visits together with audio and video recordings of actual users (e.g. gathered during lab experiments), and (iv) the ability to derive, for each user, a list of quantitative data characterizing her behavior in the VE.