Contributions to Big Geospatial Data Rendering and Visualisations

Current geographical information systems lack features and components which are commonly found within rendering and game engines. When combined with computer game technologies, a modern geographical information system capable of advanced rendering and data visualisations are achievable. We have investigated the combination of big geospatial data, and computer game engines for the creation of a modern geographical information system framework capable of visualising densely populated real-world scenes using advanced rendering algorithms. The pipeline imports raw geospatial data in the form of Ordnance Survey data which is provided by the UK government, LiDAR data provided by a private company, and the global open mapping project of OpenStreetMap. The data is combined to produce additional terrain data where data is missing from the high resolution data sources of LiDAR by utilising interpolated Ordnance Survey data. Where data is missing from LiDAR, the same interpolation techniques are also utilised. Once a high resolution terrain data set which is complete in regards to coverage, is generated, sub datasets can be extracted from the LiDAR using OSM boundary data as a perimeter. The boundaries of OSM represent buildings or assets. Data can then be extracted such as the heights of buildings. This data can then be used to update the OSM database. Using a novel adjacency matrix extraction technique, 3D model mesh objects can be generated using both LiDAR and OSM information. The generation of model mesh objects created from OSM data utilises procedural content generation techniques, enabling the generation of GIS based 3D real-world scenes. Although only LiDAR and Ordnance Survey for UK data is available, restricting the generation to the UK borders, using OSM alone, the system is able to procedurally generate any place within the world covered by OSM. In this research, to manage the large amounts of data, a novel scenegraph structure has been generated to spatially separate OSM data according to OS coordinates, splitting the UK into 1kilometer squared tiles, and categorising OSM assets such as buildings, highways, amenities. Once spatially organised, and categorised as an asset of importance, the novel scenegraph allows for data dispersal through an entire scene in real-time. The 3D real-world scenes visualised within the runtime simulator can be manipulated in four main aspects; • Viewing at any angle or location through the use of a 3D and 2D camera system. • Modifying the effects or effect parameters applied to the 3D model mesh objects to visualise user defined data by use of our novel algorithms and unique lighting data-structure effect file with accompanying material interface. • Procedurally generating animations which can be applied to the spatial parameters of objects, or the visual properties of objects. • Applying Indexed Array Shader Function and taking advantage of the novel big geospatial scenegraph structure to exploit better rendering techniques in the context of a modern Geographical Information System, which has not been done, to the best of our knowledge. Combined with a novel scenegraph structure layout, the user can view and manipulate real-world procedurally generated worlds with additional user generated content in a number of unique and unseen ways within the current geographical information system implementations. We evaluate multiple functionalities and aspects of the framework. We evaluate the performance of the system, measuring frame rates with multi sized maps by stress testing means, as well as evaluating the benefits of the novel scenegraph structure for categorising, separating, manoeuvring, and data dispersal. Uniform scaling by n2 of scenegraph nodes which contain no model mesh data, procedurally generated model data, and user generated model data. The experiment compared runtime parameters, and memory consumption. We have compared the technical features of the framework against that of real-world related commercial projects; Google Maps, OSM2World, OSM-3D, OSM-Buildings, OpenStreetMap, ArcGIS, Sustainability Assessment Visualisation and Enhancement (SAVE), and Autonomous Learning Agents for Decentralised Data and Information (ALLADIN). We conclude that when compared to related research, the framework produces data-sets relevant for visualising geospatial assets from the combination of real-world data-sets, capable of being used by a multitude of external game engines, applications, and geographical information systems. The ability to manipulate the production of said data-sets at pre-compile time aids processing speeds for runtime simulation. This ability is provided by the pre-processor. The added benefit is to allow users to manipulate the spatial and visual parameters in a number of varying ways with minimal domain knowledge. The features of creating procedural animations attached to each of the spatial parameters and visual shading parameters allow users to view and encode their own representations of scenes which are unavailable within all of the products stated. Each of the alternative projects have similar features, but none which allow full animation ability of all parameters of an asset; spatially or visually, or both. We also evaluated the framework on the implemented features; implementing the needed algorithms and novelties of the framework as problems arose in the development of the framework. Examples of this is the algorithm for combining the multiple terrain data-sets we have (Ordnance Survey terrain data and Light Detection and Ranging Digital Surface Model data and Digital Terrain Model data), and combining them in a justifiable way to produce maps with no missing data values for further analysis and visualisation. A majority of visualisations are rendered using an Indexed Array Shader Function effect file, structured to create a novel design to encapsulate common rendering effects found in commercial computer games, and apply them to the rendering of real-world assets for a modern geographical information system. Maps of various size, in both dimensions, polygonal density, asset counts, and memory consumption prove successful in relation to real-time rendering parameters i.e. the visualisation of maps do not create a bottleneck for processing. The visualised scenes allow users to view large dense environments which include terrain models within procedural and user generated buildings, highways, amenities, and boundaries. The use of a novel scenegraph structure allows for the fast iteration and search from user defined dynamic queries. The interaction with the framework is allowed through a novel Interactive Visualisation Interface. Utilising the interface, a user can apply procedurally generated animations to both spatial and visual properties to any node or model mesh within the scene. We conclude that the framework has been a success. We have completed what we have set out to develop and create, we have combined multiple data-sets to create improved terrain data-sets for further research and development. We have created a framework which combines the real-world data of Ordnance Survey, LiDAR, and OpenStreetMap, and implemented algorithms to create procedural assets of buildings, highways, terrain, amenities, model meshes, and boundaries. for visualisation, with implemented features which allows users to search and manipulate a city’s worth of data on a per-object basis, or user-defined combinations. The successful framework has been built by the cross domain specialism needed for such a project. We have combined the areas of; computer games technology, engine and framework development, procedural generation techniques and algorithms, use of real-world data-sets, geographical information system development, data-parsing, big-data algorithmic reduction techniques, and visualisation using shader techniques

Game engine for location-based services

Tese de mestrado integrado. Engenharia Informática e Computação. Universidade do Porto. Faculdade de Engenharia. 201

Geração de terrenos em tempo real

Tese de mestrado, Informática, Universidade de Lisboa, Faculdade de Ciências, 2008A geração de terrenos em tempo real é um problema complexo. Efectivamente, as necessidades de armazenamento e de processamento resultantes da quantidade de dados envolvida levantam um conjunto de problemas que tornaram esta área um tópico de investigação muito activo no domínio da computação gráfica. A maioria do trabalho efectuado concentra-se num conjunto de técnicas que procuram colmatar as dificuldades que surgem na representação de terrenos. Estas técnicas consistem sobretudo na aplicação de estratégias de culling e de nível de detalhe, com o intuito de reduzir o impacto que a representação de um terreno, especialmente os de grandes dimensões, tem ao nível do desempenho. Isto não obstante a grande evolução ao nível das placas gráficas que se tem verificado ao longo dos anos, mas que não tem sido, no entanto, suficiente para lidar com a tensão constante entre realismo e velocidade, entre fidelidade e número de frames por segundo que encontramos nesta área em particular e de uma forma geral na computação gráfica. Nesta dissertação apresentam-se conceitos fundamentais relacionados com a geração de terrenos em tempo real, tais como a representação do terreno, o particionamento espacial, o culling, o vertex caching, a coerência espacial e temporal e a utilização de vertex textures no envio dos valores elevação para o GPU. Inclui-se também a descrição dos algoritmos de geração de terrenos considerados mais relevantes, seleccionando-se dois da classe Tiled Blocks, segundo a classificação proposta por Losasso e Hoppe, para comparar o seu desempenho. Estes algoritmos aplicam duas técnicas diferentes de nível de detalhe, bastante comuns na maioria dos algoritmos desta classe e são, respectivamente, o Geomipmapping, descrito por De Boer e o GPU Terrain Rendering, descrito por Vistnes. Avaliou-se ainda a integração da técnica de occlusion culling empregue no algoritmo de Terrain Occlusion Culling With Horizons, descrito por Fiedler, e a utilização das vertex textures como alternativa no envio dos valores de elevação para o GPU. Como ponto de referência e com o intuito de avaliar a diferença a nível de desempenho, bem como verificar a necessidade de utilizar técnicas de nível de detalhe, concretizou-se também uma aproximação de “força bruta” que não utiliza nenhuma técnica de nível de detalhe.Real time terrain rendering is a complex topic. The main reason is cheer amount of geometry involved, which raises a number of problems that made this area an active topic of research in the field of computer graphics. Most of the work is centered on a group of techniques especially developed to give an answer to the problems faced when representing a terrain in real time. Culling and level of detail techniques are therefore essential tools to face the performance problems that a representation of a terrain in real time, specially a large one, brings. This despite the great technological evolution of the graphic cards over the years, which has not been, however, sufficient to deal with the constant tension between realism and speed, between fidelity and number of frames per second present in this area in particular and generally in computer graphics. In this dissertation real time terrain rendering concepts are presented, such as terrain representation models, spatial partitioning, culling, vertex caching, spatial and temporal coherence and vertex textures. Some of the most relevant real time terrain rendering algorithms are also discussed. From these, two belonging to the Tiled Blocks class, following the classification proposed by Losasso and Hope, are compared in terms of performance. These algorithms apply two different of level of detail techniques, quite common in most algorithms of this class. They are, respectively, the Geomipmapping, described by De Boer, and the GPU Terrain Rendering, described by Vistnes. Additionally the integration of the occlusion culling technique described by Fiedler on the Terrain Occlusion Culling With Horizons algorithm is evaluated as well as the use of vertex textures as way of sending the elevation values to the GPU. As a reference point and to evaluate the impact in the performance, of level of detail techniques a brute force approach that does not apply any of those techniques was also developed

Proceedings of the 9th international conference on disability, virtual reality and associated technologies (ICDVRAT 2012)

The proceedings of the conferenc

A complex systems approach to education in Switzerland

The insights gained from the study of complex systems in biological, social, and engineered systems enables us not only to observe and understand, but also to actively design systems which will be capable of successfully coping with complex and dynamically changing situations. The methods and mindset required for this approach have been applied to educational systems with their diverse levels of scale and complexity. Based on the general case made by Yaneer Bar-Yam, this paper applies the complex systems approach to the educational system in Switzerland. It confirms that the complex systems approach is valid. Indeed, many recommendations made for the general case have already been implemented in the Swiss education system. To address existing problems and difficulties, further steps are recommended. This paper contributes to the further establishment complex systems approach by shedding light on an area which concerns us all, which is a frequent topic of discussion and dispute among politicians and the public, where billions of dollars have been spent without achieving the desired results, and where it is difficult to directly derive consequences from actions taken. The analysis of the education system's different levels, their complexity and scale will clarify how such a dynamic system should be approached, and how it can be guided towards the desired performance

Advances in Forensic Genetics

The book has 25 articles about the status and new directions in forensic genetics. Approximately half of the articles are invited reviews, and the remaining articles deal with new forensic genetic methods. The articles cover aspects such as sampling DNA evidence at the scene of a crime; DNA transfer when handling evidence material and how to avoid DNA contamination of items, laboratory, etc.; identification of body fluids and tissues with RNA; forensic microbiome analysis with molecular biology methods as a supplement to the examination of human DNA; forensic DNA phenotyping for predicting visible traits such as eye, hair, and skin colour; new ancestry informative DNA markers for estimating ethnic origin; new genetic genealogy methods for identifying distant relatives that cannot be identified with conventional forensic DNA typing; sensitive DNA methods, including single-cell DNA analysis and other highly specialised and sensitive methods to examine ancient DNA from unidentified victims of war; forensic animal genetics; genetics of visible traits in dogs; statistical tools for interpreting forensic DNA analyses, including the most used IT tools for forensic STR-typing and DNA sequencing; haploid markers (Y-chromosome and mitochondria DNA); inference of ethnic origin; a comprehensive logical framework for the interpretation of forensic genetic DNA data; and an overview of the ethical aspects of modern forensic genetics