A heterogeneous data-based proposal for procedural 3D cities visualization and generalization

Ce projet de thèse est né d'un projet de collaboration entre l'équipe de recherche VORTEX/ Objets visuels: de la réalité à l'expression (maintenant REVA: Réel Expression Vie Artificielle) à l'IRIT : Institut de Recherche en Informatique de Toulouse d'une part et de professionnels de l'éducation, entreprises et entités publiques d'autre part. Le projet de collaboration SCOLA est essentiellement une plate-forme d'apprentissage en ligne basée sur l'utilisation des jeux sérieux dans les écoles. Il aide les utilisateurs à acquérir et à repérer des compétences prédéfinies. Cette plate-forme offre aux enseignants un nouvel outil flexible qui crée des scénarios liés à la pédagogie et personnalise les dossiers des élèves. Plusieurs contributions ont été attribuées à l'IRIT. L'une d'elles consiste à suggérer une solution pour la création automatique d'environnements 3D, à intégrer au scénario du jeu. Cette solution vise à empêcher les infographistes 3D de modéliser manuellement des environnements 3D détaillés et volumineux, ce qui peut être très coûteux et prendre beaucoup de temps. Diverses applications et prototypes ont été développés pour permettre à l'utilisateur de généraliser et de visualiser son propre monde virtuel principalement à partir d'un ensemble de règles. Par conséquent, il n'existe pas de schéma de représentation unique dans le monde virtuel en raison de l'hétérogénéité et de la diversité de la conception de contenus 3D, en particulier des modèles de ville. Cette contrainte nous a amené à nous appuyer largement dans notre projet sur de vraies données urbaines 3D au lieu de données personnalisées prédéfinies par le concepteur de jeu. Les progrès réalisés en infographie, les capacités de calcul élevées et les technologies Web ont largement révolutionné les techniques de reconstruction et de visualisation des données. Ces techniques sont appliquées dans divers domaines, en commençant par les jeux vidéo, les simulations et en terminant par les films qui utilisent des espaces générés de manière procédurale et des animations de personnages. Bien que les jeux informatiques modernes n'aient pas les mêmes restrictions matérielles et de mémoire que les anciens jeux, la génération procédurale est fréquemment utilisée pour créer des jeux, des cartes, des niveaux, des personnages ou d'autres facettes aléatoires uniques sur chaque jeu. Actuellement, la tendance est déplacée vers les SIG: Systèmes d'Information Géographiques pour créer des mondes urbains, en particulier après leur mise en œuvre réussie dans le monde entier afin de prendre en charge de nombreuses domaines d'applications. Les SIG sont plus particulièrement dédiés à des applications telles que la simulation, la gestion des catastrophes et la planification urbaine, avec une grande utilisation plus ou moins limitée dans les jeux, par exemple le jeu "Minecraft", dont la dernière version propose une cartographie utilisant des villes du monde réel Geodata in Minecraft. L'utilisation des données urbaines existantes devient de plus en plus répandue dans les applications cartographiques pour deux raisons principales: premièrement, elle permet de comprendre le contenu spatial d'objets urbains de manière plus logique et, deuxièmement, elle fournit une plate-forme commune pour intégrer des informations au niveau de la ville provenant de différents environnements ou ressources et les rendre accessibles aux utilisateurs. Un modèle de ville virtuelle en 3D est une représentation numérique de l'espace urbain qui décrit les propriétés géométriques, topologiques, sémantiques et d'apparence de ses composants. En général, un MV3D\footnote{Modèle de Ville en 3D} sert de plate-forme d'intégration pour plusieurs facettes d'un espace d'informations urbain, comme l'a souligné "Batty": "En bref, les nouveaux modèles ne sont pas simplement la géométrie numérique des modèles traditionnels, mais des bases de données à grande échelle pouvant être visualisées en 3D. En tant que tels, ils représentent déjà un moyen de fusionner des données symboliques ou thématiques plus abstraites, même des modèles symboliques, dans ce mode de représentation".This thesis project was born from a collaborative project between the research team VORTEX / Visual objects: from reality to expression (now REVA: Real Expression Artificial Life) at IRIT: Institute of Research in Computer Science Toulouse on the one hand and education professionals, companies and public entities on the other.The SCOLA collaborative project is essentially an online learning platform based on the use of serious games in schools. It helps users to acquire and track predefined skills. This platform provides teachers with a new flexible tool that creates pedagogical scenarios and personalizes student records. Several contributions have been attributed to IRIT. One of these is to suggest a solution for the automatic creation of 3D environments, to integrate into the game scenario. This solution aims to prevent 3D graphic designers from manually modeling detailed and large 3D environments, which can be very expensive and take a lot of time. Various applications and prototypes have been developed to allow the user to generalize and visualize their own virtual world primarily from a set of rules. Therefore, there is no single representation scheme in the virtual world due to the heterogeneity and diversity of 3D content design, especially city models. This constraint has led us to rely heavily on our project on real 3D urban data instead of custom data predefined by the game designer. Advances in computer graphics, high computing capabilities, and Web technologies have revolutionized data reconstruction and visualization techniques. These techniques are applied in a variety of areas, starting with video games, simulations, and ending with movies that use procedurally generated spaces and character animations. Although modern computer games do not have the same hardware and memory restrictions as older games, procedural generation is frequently used to create unique games, cards, levels, characters, or other random facets on each. Currently, the trend is shifting towards GIS : Geographical Information Systems to create urban worlds, especially after their successful implementation around the world to support many areas of applications. GIS are more specifically dedicated to applications such as simulation, disaster management and urban planning, with a great use more or less limited in games, for example the game "Minecraft", the latest version offers a map using real world cities Geodata in Minecraft. The use of existing urban data is becoming more and more widespread in cartographic applications for two main reasons: first, it makes it possible to understand the spatial content of urban objects in a more logical way and, secondly, it provides a common platform to integrate city-level information from different environments or resources and make them available to users. A 3D virtual city model is a digital representation of urban space that describes the geometric, topological, semantic, and appearance properties of its components. In general, an MV3D: 3D City Model serves as an integration platform for many facets of an urban information space, as "Batty" pointed out: "In short, the new models are not just the digital geometry of traditional models, but large-scale databases that can be visualized in 3D. As such, they already represent a way to merge more abstract symbolic or thematic data, even symbolic patterns, into this mode of representation"

Multifaceted facade textures for 3D city models

Three-dimensional digital representations of cities are widely used today, from urban planning to navigation systems, emergency response and to energy and flood simu- lations. Many of these scenarios can be served by one multipurpose 3D city model that has the semantic and attribute information depth that is required (besides the ge- ometrical detail). These multipurpose models do not only represent the geometrical properties and textures and materials, which would be sufficient for pure visualization of the urban space, they also model semantic entities like walls, roofs, ground, etc. And all these parts , as well as the buildings, as specific, identifiable entities, can be linked to additional information and data sets from other sources.However, although these models have the required information-richness and can be used beyond pure visualization, one part of these models is still treated the same way as for pure visualization models: the textures. Textures in most of today's city models are still a tool to enhance the photo-realistic appearance. The primary task of the textures is still to add the 'naturalistic' elements that are not modelled in geometry. These elements are mainly located in the fagades, namely windows, doors, signs, fire escapes and many more.The presented work investigates how textures can be used for information visualization, which is more useful for the aforementioned multipurpose city models. A new texture concept is presented that is based on flexible content, which is managed in layers. In this way it is possible to adapt the appearance of buildings (especially fagades) to the actual scenario. The concept also allows the integration of additional information into the fagade, enhancing the 3D city model. In this way it is possible to generate scenario specific fagade textures integrating the relevant information into the texture content

Représentations cartographiques intermédiaires : comment covisualiser une carte et une orthophotographie pour naviguer entre abstraction et réalisme ?

Two representations of the territory are widely provided simultaneously to the user through interactive tools (such as magnifiers, sliders or swipes): topographic maps and orthoimages. They provide complementary visions of the territory because of abstraction steps used to design maps and the intrisic perceived photorealism power of orthoimages. Aiming at providing efficient covisualizations of these two representations to the user, we advise not to search for an ideal graphic mix, but to produce a cartographic continuum composed of in-between representations mixing topographic data and orthoimagery. Our objective is to provide interactive tools allowing to choose an intermediate step within the continuum by controling the realism and abstraction levels. Our approach is based on three principles: first, the need for local adaptation of vector data symbolisation to preserve their readability, second, the call for graphic transitions to establish a continuity through in-between cartographic representations, and third the required control over realism level in order to ensure a visual consistency of hybrid visualisations. We provide elementary symbolisation methods to be combined in a global design process. The first one aims at interpolating SLD symbolisation parameters such as color, opacity or texturing between two symbolisations. The second one aims at defining a local symbolisation depending on the graphic context of objects to be highlighted. Those symbolisations are combined for each theme and synchronized for all themes. For these design steps, we provide guidelines based on the evaluation of the realism level coming from our user test. Finally we build a prototype software allowing to test our propositions and browse in-between representations from abstraction to realism through an interactive sliderDeux représentations du territoire sont majoritairement proposées pour être covisualisées de multiples façons (loupe, curseurs, vues asservies, etc.) : la carte topographique et l'orthophotographie. Ces deux représentations apportent une vision complémentaire du territoire : la carte topographique est l'archétype même de l'abstraction et l'orthophotographie renvoie une perception réaliste du territoire. Pour permettre à l'utilisateur de covisualiser ces deux types de représentations, nous préconisons de ne pas chercher un mélange graphique idéal mais plutôt de produire un continuum cartographique formé d'un ensemble continu de représentations intermédiaires mixant données topographiques et orthophotographie. Notre objectif est de permettre à l'utilisateur de choisir sa position entre les deux extrémités en contrôlant le degré de réalisme et d'abstraction tout au long du continuum. Notre approche se fonde sur la nécessité d'adaptation locale de la symbolisation des données topographiques pour assurer la lisibilité de chaque représentation intermédiaire, la création de transitions graphiques pour établir une continuité entre ces représentations, et la synchronisation des symbolisations visant à garantir une homogénéité visuelle de ces représentations mixtes. Nous proposons une méthode de conception reposant sur la combinaison de briques de symbolisation élémentaires. Le premier type de brique consiste à interpoler les paramètres de symbolisation de la norme SLD tels que la couleur, la transparence ou la texture (procédurale, naturelle, ou mixée) entre deux symbolisations données. Le second type de brique analyse le contexte graphique des objets à mettre en valeur afin de déterminer localement une symbolisation adaptée et lisible. Ces briques sont combinées pour chaque thème et coordonnées entre les différents thèmes. Nous émettons des préconisations de paramétrage de ces étapes de conception à partir des résultats de notre test utilisateur visant à estimer le degré de réalisme et d'abstraction des symbolisations cartographiques. Enfin, nous mettons en œuvre cette méthode de conception au sein de la plateforme de recherche GeOxygene sous la forme d'un outil permettant de naviguer dans un continuum cartographique entre réalisme et abstractio

The impact of 3D virtual environments with different levels of realism on route learning: a focus on age-based differences

With technological advancements, it has become notably easier to create virtual environments (VEs) depicting the real world with high fidelity and realism. These VEs offer some attractive use cases for navigation studies looking into spatial cognition. However, such photorealistic VEs, while attractive, may complicate the route learning process as they may overwhelm users with the amount of information they contain. Understanding how much and what kind of photorealistic information is relevant to people at which point on their route and while they are learning a route can help define how to design virtual environments that better support spatial learning. Among the users who may be overwhelmed by too much information, older adults represent a special interest group for two key reasons: 1) The number of people over 65 years old is expected to increase to 1.5 billion by 2050 (World Health Organization, 2011); 2) cognitive abilities decline as people age (Park et al., 2002). The ability to independently navigate in the real world is an important aspect of human well-being. This fact has many socio-economic implications, yet age-related cognitive decline creates difficulties for older people in learning their routes in unfamiliar environments, limiting their independence. This thesis takes a user-centered approach to the design of visualizations for assisting all people, and specifically older adults, in learning routes while navigating in a VE. Specifically, the objectives of this thesis are threefold, addressing the basic dimensions of: ❖ Visualization type as expressed by different levels of realism: Evaluate how much and what kind of photorealistic information should be depicted and where it should be represented within a VE in a navigational context. It proposes visualization design guidelines for the design of VEs that assist users in effectively encoding visuospatial information. ❖ Use context as expressed by route recall in short- and long-term: Identify the implications that different information types (visual, spatial, and visuospatial) have over short- and long-term route recall with the use of 3D VE designs varying in levels of realism. ❖ User characteristics as expressed by group differences related to aging, spatial abilities, and memory capacity: Better understand how visuospatial information is encoded and decoded by people in different age groups, and of different spatial and memory abilities, particularly while learning a route in 3D VE designs varying in levels of realism. In this project, the methodology used for investigating the topics outlined above was a set of controlled lab experiments nested within one. Within this experiment, participants’ recall accuracy for various visual, spatial, and visuospatial elements on the route was evaluated using three visualization types that varied in their amount of photorealism. These included an Abstract, a Realistic, and a Mixed VE (see Figure 2), for a number of route recall tasks relevant to navigation. The Mixed VE is termed “mixed” because it includes elements from both the Abstract and the Realistic VEs, balancing the amount of realism in a deliberate manner (elaborated in Section 3.5.2). This feature is developed within this thesis. The tested recall tasks were differentiated based on the type of information being assessed: visual, spatial, and visuospatial (elaborated in Section 3.6.1). These tasks were performed by the participants both immediately after experiencing a drive-through of a route in the three VEs and a week after that; thus, addressing short- and long-term memory, respectively. Participants were counterbalanced for their age, gender, and expertise while their spatial abilities and visuospatial memory capacity were controlled with standardized psychological tests. The results of the experiments highlight the importance of all three investigated dimensions for successful route learning with VEs. More specifically, statistically significant differences in participants’ recall accuracy were observed for: 1) the visualization type, highlighting the value of balancing the amount of photorealistic information presented in VEs while also demonstrating the positive and negative effects of abstraction and realism in VEs on route learning; 2) the recall type, highlighting nuances and peculiarities across the recall of visual, spatial, and visuospatial information in the short- and long-term; and, 3) the user characteristics, as expressed by age differences, but also by spatial abilities and visuospatial memory capacity, highlighting the importance of considering the user type, i.e., for whom the visualization is customized. The original and unique results identified from this work advance the knowledge in GIScience, particularly in geovisualization, from the perspective of the “cognitive design” of visualizations in two distinct ways: (i) understanding the effects that visual realism has—as presented in VEs—on route learning, specifically for people of different age groups and with different spatial abilities and memory capacity, and (ii) proposing empirically validated visualization design guidelines for the use of photorealism in VEs for efficient recall of visuospatial information during route learning, not only for shortterm but also for long-term recall in younger and older adults

Cognitive Foundations for Visual Analytics

In this report, we provide an overview of scientific/technical literature on information visualization and VA. Topics discussed include an update and overview of the extensive literature search conducted for this study, the nature and purpose of the field, major research thrusts, and scientific foundations. We review methodologies for evaluating and measuring the impact of VA technologies as well as taxonomies that have been proposed for various purposes to support the VA community. A cognitive science perspective underlies each of these discussions

Visual analytics methods for retinal layers in optical coherence tomography data

Optical coherence tomography is an important imaging technology for the early detection of ocular diseases. Yet, identifying substructural defects in the 3D retinal images is challenging. We therefore present novel visual analytics methods for the exploration of small and localized retinal alterations. Our methods reduce the data complexity and ensure the visibility of relevant information. The results of two cross-sectional studies show that our methods improve the detection of retinal defects, contributing to a deeper understanding of the retinal condition at an early stage of disease.Die optische Kohärenztomographie ist ein wichtiges Bildgebungsverfahren zur Früherkennung von Augenerkrankungen. Die Identifizierung von substrukturellen Defekten in den 3D-Netzhautbildern ist jedoch eine Herausforderung. Wir stellen daher neue Visual-Analytics-Methoden zur Exploration von kleinen und lokalen Netzhautveränderungen vor. Unsere Methoden reduzieren die Datenkomplexität und gewährleisten die Sichtbarkeit relevanter Informationen. Die Ergebnisse zweier Querschnittsstudien zeigen, dass unsere Methoden die Erkennung von Netzhautdefekten in frühen Krankheitsstadien verbessern

Ocean Solutions, Earth Solutions

What affects the oceans affects terra firma. Ocean Solutions, Earth Solutions gathers the insights of more than 50 ocean and coastal science researchers exploring ocean components and their relationships, patterns, and trends over time and space. The book's 16 chapters feature geographic information system (GIS) best practices and include additional online resources.The book is edited by oceanographer and Esri Chief Scientist Dawn J. Wright and features a foreword by oceanographer David Gallo, director of special projects for the Woods Hole Oceanographic Institution in Massachusetts.Keywords: marine resource management, GIS, mapping, ocean conservation, ocean scienc