Abstract

Abstract
Nowadays, there is a wide range of commercial LBMS (Location-Based Mobile Services) available in the market, mainly in the form of GPS-based navigation solutions, and a trend towards the display of 3D maps can be clearly observed. Given the complete disparity of ideas and a visible commercial orientation in the industry, the study of the visualisation aspects that influence user performance and experience in the exploration of urban environments using 3D maps becomes an important issue. In this work, a generic conceptual framework is proposed whose main purpose is to objectively evaluate the impact and contribution of the major visualisation elements involved (henceforth mentioned as feature vectors). With this framework in mind, an online questionnaire was developed and administered to 149 test subjects in order to measure the real impact of feature vectors. The results clearly demonstrated that certain features have clear impact on user performance, and should be taken in account in LBMS development. As an example, just by displaying buildings with a 3D appearance, subjects were able to match more accurately the real environment with the one presented on a mobile device. In general, users were able to perform the tasks entrusted to them faster, if they were provided more realistic imagery.

Abstract
Nowadays, there is a wide range of commercial LBMS (Location-Based Mobile Services) available in the market, and a trend towards the display of 3D maps can be clearly observed. Given the complete disparity of ideas and a visible commercial orientation in the industry, the study of the visualization aspects that influence user performance and experience in the exploration of urban environments, using 3D maps, becomes an important issue. Based on a proposed conceptual framework, an online questionnaire was developed and administered in order to measure the real impact of each element. Combining the experimental results with the current state-of-the-art, a new visualization paradigm is defined in a dual specification: "layers" providing relevant visual content to the map, and "functions" providing the necessary functionality.

Abstract
This paper presents a solution for geometric manipulation in procedural modeling as an Application Programming Interface (API). This approach intends to enable a more powerful control over the geometric entities by performing selections based on their attributes, similar to picking features in graphical interfaces. This is achieved through the definition of a topological structure, which features a set of properties, such as scope, spatial localization and semantic information. The applicable modeling operations allow a more customized control, as well as successive tracking, which induce a greater, faster and more intuitive approach for geometry generation. This approach still constitutes ongoing work, but has already been successfully applied for the generation of large virtual urban environments.

Abstract
People with autism spectrum disorder (ASD) find it difficult to recognize and respond to emotions conveyed by the face. Most existing methodologies to teach people with ASD to recognize expressions use still images, and do not take into account that facial expressions have movement. We propose a new approach that uses state of the art technology to solve the problem and to improve interactivity. It is based on an avatar-user interaction model with real time response, which builds upon the patient-therapist relationship: it is designed to be used by the therapist and the patient. The core technology behind it is based on a technique we have developed for real time facial synthesis of 3D characters.

Abstract
L-systems have been used in Computer Graphics, namely for modelling plants, as well as in a few experiments to model urban environments. However, the lack of geospatial awareness is a limitation and in spite of some developments like open L-systems, that introduced the ability to communicate with the environment, there was a need for more flexibility. This paper presents Geospatial L-systems, a new extension of L-systems that incorporates geospatial awareness, and shows an application in the area of expeditious modelling of urban environments. A modelling system, named XL3D, generates virtual urban environments automatically from a XML based document that contains a modelling specification and accesses data sources in an interoperable way. The integration of geospatial L-systems in this modelling system has increased the potential for automation and the potential to generate virtual urban environments with a higher level of detail and visual fidelity, with a lower level of complexity of the modelling processes. These facts are shown in a case study where a virtual urban environment, taken from an area in the Porto downtown, is generated by this solution.