Networks can be represented as node-link diagram. In geo-referenced networks, the used node-link diagram has nodes placed accordingly with geographical criteria. Different graph drawing techniques can be applied on such layout to improve their readability. This work proposes a systematization of node link layouts and graph drawing techniques. We use the proposed schematization to classify geographic node-link diagrams. A unified classification of layouts and drawing techniques has several advantages. On the developer perspective, the design of a specific layout is driven by the understanding of graph drawing techniques. On the user perspective, graph drawing techniques applied to improve the layout readability are specifically designed for a subset of layouts.

This paper illustrates the preliminary results of a research project focused on the development of a Web 2.0 system designed to compute and visualize large-scale building energy performance maps, so called “ecomaps”, using emerging platform-independent technologies such as WebGL for data presentation, an extended version of the EU-Founded project TABULA/EPISCOPE for automatic calculation of building energy parameters and CityGML OGC standard as data container. The proposed architecture will allow citizens, public administrations and government agencies to perform city-wide analyses on the energy performance of building stocks.

This work presents a novel approach to author multimodal interaction dialogue of a VR system according to each users specific preferences. We will show how modalities can be bound together via a bidirectional graph in an authoring tool to allow the specification of application-specific domain commands without hardwiring them to the application. As a result we provide a persistent definition of the used modalities outside the application. This is done through the adoption of a so-called "interaction graph" whose nodes and edges represent the dialogue of the user with the system. The application then identifies interaction patterns by matching the path within the graph that represents the actions the user wants to perform within the application.

This paper illustrates the results of the DentroTrento project which promotes historical, artistic and cultural heritage in the area of Trentino through the use of Virtual Reality technologies. The project's goal was to implement an user friendly system which could be used by visitors of an archeological site thus fostering a process of cultural enrichment. The importance of the project, commissioned by the authority for Cultural Heritage, partially resides in the peculiarity of the site's premises, located below a square in Trento among the theatre's foundations. The interface developed allows users speaking different languages to share simultaneously the experience of virtual tour across time.

This paper presents a novel method for efficient boundary based shapes matching and retrieval in presence of occlusion. In this method, the geometric and topological information of boundary curves are encoded in the form of longest common subcurves (LCS) graphs and their similarity is estimated by graph matching. B-Spline is used for approximating the original boundary, then inflection points are detected to split such a B-spline to convex/concave segments. The characteristic string is constructed based on these segments' canonical frame. After LCS candidates are found, their graphs which are constructed by using its segments as vertices and the weighted walkthrough (WW) between two segments as edges are compared to obtain the optimal match. Thorough experimental results and comparisons demonstrate that our method outperforms traditional LCS or dynamic programming based methods in shape matching and enhances the quality of inexact shape retrieval, in particular in the presence of occlusions and affine transformation.

In this paper, an efficient method for boundary-based shapes matching and retrieval in the presence of occlusion is presented. The geometric and topological information of boundary curves are encoded in the form of longest common sub-curves (LCS) graphs and their similarity is estimated by graph matching. B-spline is used for approximating the original boundary, then inflection points are detected to split such a Bspline to convex/concave segments. The characteristic string is constructed based on these segments' canonical frame. After LCS candidates are found, their graphs, which are constructed using their segments as vertices and the weighted walkthrough (WW) between two segments as edges, are compared to obtain the optimal match. The experimental results and comparisons demonstrate that the proposed method outperforms traditional boundary-based methods in shape matching and it enhances the quality of inexact shape retrieval

This paper tries to answer to the increasing demand for more intuitive methods for creating and modifying free-form curves and surfaces which is emerging in the field of conceptual design. We present a novel approach which adopts a simple 3D sketching technique together with a finite element deformation method to create free-form models. The method proposed lets the user interactively sculpt splines to modify a surface in a predicable way. Our algorithm automatically extracts the key points from the sketched "target curve" and it adaptively distributes the external-force constraints which impose the forces on the corresponding vertices along their normals. We have limited the influence of these constraints to a localized area by attaching an influence factor to each vertex of the parent surface. The smoothing function introduced later allows good control over the transition intervals and the symmetry features. The proposed method is finally implemented within a 3D environment and the results of its use show how the designers can intuitively and exactly control the shape of the sketched surface.

The capability of processing spoken commands is one of the most important features of modern multimodal AR/VR environments. This feature requires programmers to compile some human supplied knowledge in the form of grammars which are used at runtime to process spoken utterances into complete commands. Further speech recognition (SR) must be hard-coded into the application. This time-consuming, error-prone process is repeated every time modifications to the code are introduced. This paper presents a completely automatic process to build a body of knowledge from the information embedded within the application source code. The programmer in fact often embeds, throughout the coding process, a vast amount of semantic information by defining classes, reference names, or through method definitions. This research work exploits this semantic richness and it provides a self-configurable system, which automatically adapts its understanding of human commands according to the semantic information within the application's source code

In the fields of industrial design and car manufacturing the creation of 3D curves plays a fundamental role within the design process: it allows the improvement of the visual appeal of artifacts, it enhances ergonomics and the product's commercial competitiveness through product differentiation. When flexibility and intuition are to be privileged it is fundamental to achieve natural, intuitive, mathematically correct, creation and modification of surfaces.The scientific aim of this research is the development of an innovative metaphor to modeling of 3D curves which maintains the natural expertise of the designer. The major contribution of this paper is the capability of the system to create and modify the curve naturally, without mathematical artifices, within the limits set by the use of Bezier curves.The proposed metaphor combines the benefits of two acknowledged techniques referred to as the Digital Tape Drawing and the Eraser Pen, which allow the real-time modification of the curve. The integrated adoption of tangible interfaces and innovative mathematical tools, combined with the adoption of semi-immersive environment and lightweight interaction devices, delivers intuitive curve creation for free-form modeling within the virtual scene. The paper describes the details of the algorithm developed and it highlights its strengths during the styling phase.

Spacedesign is an innovative mixed reality (MR) application addressed to aesthetic design of free form curves and surfaces. It is a unique and comprehensive approach which uses task-specific configurations to support the design workflow from concept to mock-up evaluation and review. The first-phase conceptual design benefits from a workbench-like 3-D display for free hand sketching, surfacing and engineering visualization. Semitransparent stereo glasses augment the pre-production physical prototype by additional shapes, textures and annotations. Both workspaces share a common interface and allow collaboration and cooperation between different experts, who can configure the system for the specific task. A faster design workflow and CAD data consistency can be thus naturally achieved. Tests and collaborations with designers, mainly from automotive industry, are providing systematic feedback for this ongoing research. As far as the authors are concerned, there is no known similar approach that integrates the creation and editing phase of 3D curves and surfaces in virtual and augmented reality (VR/AR). Herein we see the major contribution of our new application.