Dissertations / Theses on the topic 'Plant 3D modeling'

Doctor of Philosophy
Agronomy
Kevin Price
Stephen M. Welch
Plant phenotyping has been studied for decades for understanding the relationship between plant genotype, phenotype, and the surrounding environment. Improved accuracy and efficiency in plant phenotyping is a critical factor in expediting plant breeding and the selection process. In the past, plant phenotypic traits were extracted using invasive and destructive sampling methods and manual measurements, which were time-consuming, labor-intensive, and cost-inefficient. More importantly, the accuracy and consistency of manual methods can be highly variable. In recent years, however, photogrammetry and 3D modeling techniques have been introduced to extract plant phenotypic traits, but no cost-efficient methods using these two techniques have yet been developed for large-scale plant phenotyping studies. High-throughput 3D modeling techniques in plant biology and agriculture are still in the developmental stages, but it is believed that the temporal and spatial resolutions of these systems are well matched to many plant phenotyping needs. Such technology can be used to help rapid phenotypic trait extraction aid crop genotype selection, leading to improvements in crop yield. In this study, we introduce an automated high-throughput phenotyping pipeline using affordable imaging systems, image processing, and 3D reconstruction algorithms to build 2D mosaicked orthophotos and 3D plant models. Chamber-based and ground-level field implementations can be used to measure phenotypic traits such as leaf length, rosette area in 2D and 3D, plant nastic movement, and diurnal cycles. Our automated pipeline has cross-platform capabilities and a degree of instrument independence, making it suitable for various situations.

Le défi de cette thèse est de reconstruire la géométrie 3D de la végétation à partir des données de distance et d'intensité fournies par un scanner de type LiDAR. Une méthode de « shape-from-shading » par propagation est développée pour être combinée avec une méthode de fusion de données type filtre de Kalman pour la reconstruction optimale des surfaces foliaires.-Introduction-L'analyse des données LiDAR nous permet de dire que la qualité du nuage de point est variable en fonction de la configuration de la mesure : lorsque le LiDAR mesure le bord d'une surface ou une surface fortement inclinée, il intègre dans sa mesure une partie de l'arrière plan. Ces configurations de mesures produisent des points aberrants. On retrouve souvent ce type de configuration pour la mesure de feuillages puisque ces derniers ont des géométries fragmentées et variables. Les scans sont en général de mauvaise qualité et la quantité d'objets présents dans le scan rend la suppression manuelle des points aberrants fastidieuse. L'objectif de cette thèse est de développer une méthodologie permettant d'intégrer les données d'intensité LiDAR aux distances pour corriger automatiquement ces points aberrants. -Shape-From-Shading-Le principe du Shape-From-Shading (SFS) est de retrouver les valeurs de distance à partir des intensités d'un objet pris en photo. La caméra (capteur LiDAR) et la source de lumière (laser LiDAR) ont la même direction et sont placés à l'infini relativement à la surface, ce qui rend l'effet de la distance sur l'intensité négligeable et l'hypothèse d'une caméra orthographique valide. En outre, la relation entre angle d'incidence lumière/surface et intensité est connue. Par la nature des données LiDAR, nous pourrons choisir la meilleure donnée entre distance et intensité à utiliser pour la reconstruction des surfaces foliaires. Nous mettons en place un algorithme de SFS par propagation le long des régions iso-intenses pour pouvoir intégrer la correction de la distance grâce à l'intensité via un filtre de type Kalman. -Design mathématique de la méthode-Les morceaux de surface correspondant aux régions iso-intenses sont des morceaux de surfaces dites d'égales pentes, ou de tas de sable. Nous allons utiliser ce type de surface pour reconstruire la géométrie 3D correspondant aux images d'intensité.Nous démontrons qu'à partir de la connaissance de la 3D d'un bord d'une région iso-intense, nous pouvons retrouver des surfaces paramétriques correspondant à la région iso-intense qui correspondent aux surfaces de tas de sable. L'initialisation de la région iso-intense initiale (graine de propagation) se fait grâce aux données de distance LiDAR. Les lignes de plus grandes pentes de ces surfaces sont générées. Par propagation de ces lignes (et donc génération du morceau de la surface en tas de sable), nous déterminons l'autre bord de la région iso-intense. Puis, par itération, nous propagerons la reconstruction de la surface. -Filtre de Kalman-Nous pouvons considérer cette propagation des lignes de plus grande pente comme étant le calcul d'une trajectoire sur la surface à reconstruire. Dans le cadre de notre étude, la donnée de distance est toujours disponible (données du scanner 3D). Ainsi il est possible de choisir, lors de la propagation, quelle donnée (distance ou intensité) utiliser pour la reconstruction. Ceci peut être fait notamment grâce à une fusion de type Kalman. -Algorithme-Pour procéder à la reconstruction par propagation, il est nécessaire d'hiérarchiser les domaines iso-intenses de l'image. Une fois que les graines de propagation sont repérées, elles sont initialisées avec l'image des distances. Enfin, pour chacun des nœuds de la hiérarchie (représentant un domaine iso-intense), la reconstruction d'un tas de sable est faite. C'est lors de cette dernière étape qu'une fusion de type Kalman peut être introduite
The challenge of this thesis is reconstruct the 3D geometry of vegetation from distance and intensity data provided by a 3D scanner LiDAR. A method of “Shape-From-Shading” by propagation is developed to be combined with a fusion method of type “Kalman” to get an optimal reconstruction of the leaves. -Introduction-The LiDAR data analysis shows that the point cloud quality is variable. This quality depends upon the measurement set up. When the LiDAR laser beam reaches the edge of a surface (or a steeply inclined surface), it also integrate background measurement. Those set up produce outliers. This kind of set up is common for foliage measurement as foliages have in general fragmented and complex shape. LiDAR data are of bad quality and the quantity of leaves in a scan makes the correction of outliers fastidious. This thesis goal is to develop a methodology to allow us to integrate the LiDAR intensity data to the distance to make an automatic correction of those outliers. -Shape-from-shading-The Shape-from-shading principle is to reconstruct the distance values from intensities of a photographed object. The camera (LiDAR sensor) and the light source (LiDAR laser) have the same direction and are placed at infinity relatively to the surface. This makes the distance effect on intensity negligible and the hypothesis of an orthographic camera valid. In addition, the relationship between the incident angle light beam and intensity is known. Thanks to the LiDAR data analysis, we are able to choose the best data between distance and intensity in the scope of leaves reconstruction. An algorithm of propagation SFS along iso-intense regions is developed. This type of algorithm allows us to integrate a fusion method of type Kalman. -Mathematical design of the method-The patches of the surface corresponding to the iso-intense regions are patches of surfaces called the constant slope surfaces, or sand-pile surfaces. We are going to use those surfaces to rebuild the 3D geometry corresponding to the scanned surfaces. We show that from the knowledge of the 3d of an iso-intensity region, we can construct those sand-pile surfaces. The initialization of the first iso-intense regions contour (propagation seeds) is done with the 3D LiDAR data. The greatest slope lines of those surfaces are generated. Thanks to the propagation of those lines (and thus of the corresponding sand-pile surface), we build the other contour of the iso-intense region. Then, we propagate the reconstruction iteratively. -Kalman filter-We can consider this propagation as being the computation of a trajectory on the reconstructed surface. In our study framework, the distance data is always available (3D scanner data). It is thus possible to choose which data (intensity vs distance) is the best to reconstruct the object surface. This can be done with a fusion of type Kalman filter. -Algorithm-To proceed a reconstruction by propagation, it is necessary to order the iso-intensity regions. Once the propagation seeds are found, they are initialized with the distances provided by the LiDAR. For each nodes of the hierarchy (corresponding to an iso-intensity region), the sand-pile surface reconstruction is done. -Manuscript-The thesis manuscript gathers five chapters. First, we give a short description of the LiDAR technology and an overview of the traditional 3D surface reconstruction from point cloud. Then we make a state-of-art of the shape-from –shading methods. LiDAR intensity is studied in a third chapter to define the strategy of distance effect correction and to set up the incidence angle vs intensity relationship. A fourth chapter gives the principal results of this thesis. It gathers the theoretical approach of the SFS algorithm developed in this thesis. We will provide its description and results when applied to synthetic images. Finally, a last chapter introduces results of leaves reconstruction

Thesis (MScEng (Mathematical Sciences. Applied Mathematics))--Stellenbosch University, 2008.
When building or improving a petrochemical plant, drawings are used extensively in the design process. However, existing petrochemical plants seldom match their drawings, or the drawings are lost, forcing the need to generate a 3D model of the structure of the plant. In this thesis photogrammetry is investigated as a method of generating a digital 3D model of an existing plant. Camera modeling, target extraction and 3D reconstruction are discussed in detail, and a real-world system is investigated.

Some experts suggest that urban design plans in US cities may lack adequate coverage of the essential design aspects, particularly three-dimensional design aspects of the physical environment. Digital urban models and information technology tools may help designers visualize and interact with design alternatives, large urban data sets, and 3D information more effectively, thus correcting this problem. However, there is a limited understanding of the impact that these models may have on the quality of the design product and consequently hesitation about the appropriate methods of their usage. These suggest a need for research into how the usage of digital models can affect the extent with which urban design plans cover the essential design aspects. This research discusses the role digital models can play in supporting designers in addressing the essential design aspects. The research objective is to understand how the usage of digital models affects the coverage of the essential design aspects. The research applies a novel perspective of examining both the methods of modeling-supported urban design and the design content of urban design to attempt to reveal a correlation or causal relation. Using the mixed method approach, this research includes three phases. The first, literature review, focused on reviewing secondary sources to construct theoretical propositions about the impact of digital modeling on urban design against which empirical observations were compared. Using qualitative content analysis, the second phase involved examining 14 plans to assess their design content and conducting structured interviews with the designers of four selected plans. The third phase involved sending questionnaire forms to designers in the planning departments and firms that developed the examined plans. The analysis results were compared with the theoretical propositions and discussed to derive conclusions. The extent of design aspects coverage was found to be correlated with the usage of digital modeling. Computational plans appear to have achieved a higher level of design aspects coverage and a better translation of design goals and objectives. In those plans, 3D urban-wide design aspects were addressed more effectively than in conventional plans. The effective usage of the model's functions appears to improve the quality of the decision-making process through increasing designers' visualization and analytical capabilities, and providing a platform for communicating design ideas among and across design teams. The results helped suggest a methodological framework for the best practices of modeling usage to improve the design content.

La population mondiale augmente rapidement, et avec elle, le nombre de citadins, ce qui rend d'autant plus importantes la planification et la gestion des villes.La gestion "intelligente" de ces villes et les nombreuses applications (gestion, tourisme virtuel, simulation de trafic, etc.) nécessitent plus de données réunies dans des modèles virtuels de villes.En milieu urbain, les rues et routes sont essentielles par leur rôle d'interface entre les espaces publics et privés, et entre ces différents usages.Il est difficile de modéliser les rues (ou de les reconstruire virtuellement) car celles-ci sont très diverses (de par leur forme, fonction, morphologie), et contiennent des objets très divers (mobilier, marquages, panneaux).Ce travail de thèse propose une méthode (semi-) automatique pour reconstruire des rues en utilisant le paradigme de la modélisation procédurale inverse dont le principe est de générer un modèle procéduralement, puis de l'adapter à des observations de la réalité.Notre méthode génère un premier modèle approximatif - à partir de très peu d'informations (un réseau d'axes routiers + attributs associés) - assez largement disponible.Ce modèle est ensuite adapté à des observations de façon interactive (interaction en base compatible avec les logiciels SIG communs) et (semi-) automatique (optimisation).L'adaptation (semi-) automatique déforme le modèle de route de façon à ce qu'il corresponde à des observations (bords de trottoir, objets urbains) extraites d'images et de nuages de points.La génération (StreetGen) et l'édition interactive se font dans un serveur de base de données ; de même que la gestion des milliards de points Lidar (Point Cloud Server).La génération de toutes les rues de la ville de Paris prends quelques minutes, l'édition multi-utilisateurs est interactive (<0.3 s). Les premiers résultats de l'adaptation (semi-) automatique (qq minute) sont prometteurs (la distance moyenne à la vérité terrain passe de 2.0 m à 0.5 m).Cette méthode, combinée avec d'autres telles que la reconstruction de bâtiment, de végétation, etc., pourrait permettre rapidement et semi automatiquement la création de modèles précis et à jour de ville
World urban population is growing fast, and so are cities, inducing an urgent need for city planning and management.Increasing amounts of data are required as cities are becoming larger, "Smarter", and as more related applications necessitate those data (planning, virtual tourism, traffic simulation, etc.).Data related to cities then become larger and are integrated into more complex city model.Roads and streets are an essential part of the city, being the interface between public and private space, and between urban usages.Modelling streets (or street reconstruction) is difficult because streets can be very different from each other (in layout, functions, morphology) and contain widely varying urban features (furniture, markings, traffic signs), at different scales.In this thesis, we propose an automatic and semi-automatic framework to model and reconstruct streets using the inverse procedural modelling paradigm.The main guiding principle is to generate a procedural generic model and then to adapt it to reality using observations.In our framework, a "best guess" road model is first generated from very little information (road axis network and associated attributes), that is available in most of national databases.This road model is then fitted to observations by combining in-base interactive user edition (using common GIS software as graphical interface) with semi-automated optimisation.The optimisation approach adapts the road model so it fits observations of urban features extracted from diverse sensing data.Both street generation (StreetGen) and interactions happen in a database server, as well as the management of large amount of street Lidar data (sensing data) as the observations using a Point Cloud Server.We test our methods on the entire Paris city, whose streets are generated in a few minutes, can be edited interactively (<0.3 s) by several concurrent users.Automatic fitting (few m) shows promising results (average distance to ground truth reduced from 2.0 m to 0.5m).In the future, this method could be mixed with others dedicated to reconstruction of buildings, vegetation, etc., so an affordable, precise, and up to date City model can be obtained quickly and semi-automatically.This will also allow to such models to be used in other application areas.Indeed, the possibility to have common, more generic, city models is an important challenge given the cost an complexity of their construction

Localization and mapping are vital capabilities for a mobile robot. These two capabilities strongly depend on each other and simultaneously executing both of these operations is called SLAM (Simultaneous Localization and Mapping). SLAM problem requires the environment to be represented with an abstract mapping model. It is possible to construct a map from point cloud of environment via scanner sensor systems. On the other hand, extracting higher level of features from point clouds and using these extracted features as an input for mapping system is also a possible solution for SLAM. In this work, a 4D feature based EKF SLAM system is constructed and open form of equations of algorithm are presented. The algorithm is able to use center of mass and direction of features as input parameters and executes EKF SLAM via these parameters. Performance of 4D feature based EKF SLAM was examined and compared with 3D EKF SLAM via monte-carlo simulations. By this way
it is believed that, contribution of adding a direction vector to 3D features is investigated and illustrated via graphs of monte-carlo simulations. At the second part of the work, a scanner sensor system with IR distance finder is designed and constructed. An algorithm was presented to extract planar features from data collected by sensor system. A noise model was proposed for output features of sensor and 4D EKF SLAM algorithm was executed via extracted features of scanner system. By this way, performance of 4D EKF SLAM algorithm is tested with real sensor data and output results are compared with 3D features. So in this work, contribution of using 4D features instead of 3D ones was examined via comparing performance of 3D and 4D algorithms with simulation results and real sensor data.

Three-dimensionally woven composites are a relatively new class of material that offer improved out-of-plane performance by including through-the-thickness mechanical reinforcement compared to traditional laminated composite structures. The mechanical properties are highly dependent upon the weave architecture as this dictates the nature of the through the thickness reinforcement and its effect in improving out-of-plane shear strength. A comparison of two testing methods, Short Beam Strength, and Five Point Bending was conducted over a range of span to thickness ratios with the latter found to be more consistent at producing shear failure over a greater range of span to thickness ratios, although evidence of matrix crushing was present in both, and flexural failure in the Short Beam Strength test. Two weave architectures, the orthogonal and angle weave were subjected to the Five Point Bending test and the failure and damage progression behaviour of both weave architectures were characterised using Digital Image Correlation analysis to measure the edge strain through the thickness of the specimens. This testing showed the angle weave architecture had in general a higher failure strength, and more gradual failure due to longer debonding cracks. The orthogonal weave architecture showed a characteristic post-failure response indicative of crack bridging with discrete load recovery and load drop phases. A numerical model developed from previous work builds on the mosaic modelling method and was modified to include cohesive elements in order to simulate interface debonding via the maximum stress criterion. The simulations are consistently 15 20% greater in failure loads, and 8 - 12% greater in failure shear stresses than those found from the averaged experimental results over the range of tested span to thickness ratios. Post failure response was not modelled. The work presented in this thesis is another step towards gaining a thorough understanding of the mechanical properties of 3D woven composite structures, focussing in particular on out of plane shear strength. The modified mosaic modelling method used showed it is effective at modelling the out of plane testing of orthogonal 3D woven composite structures, and offer the potential to predict the failure of larger composite structures of the same construction and 3D woven architecture although developments are still needed in modelling the post failure response.

Nous explorons le problème de la reconstruction complète d’un environnement intérieur en utilisant des données mixtes issues de la caméra RGB-D (couleur plus profondeur) de faible coût et de la centrale inertielle. Le processus de numérisation est réalisé en temps réel, en déplacement avec 6 degrés de liberté du système de numérisation. Nous nous concentrons sur les systèmes mobiles avec des contraintes informatiques, tels que les smartphones ou les tablettes. Les problèmes problématiques présentent un ensemble de défis fondamentaux : l'estimation du positionnement et de la trajectoire du périphérique lorsqu'il se déplace pendant l'acquisition de l'environnement et l'utilisation de structures de données légères pour stocker la représentation de la scène reconstruite. Le système doit être optimisé et efficace pour la mémoire, de sorte qu'il puisse fonctionner en temps réel, à bord de l'équipement mobile. Nous proposons également une nouvelle méthode de reconstruction de la surface, nommé Dodécaèdre Mapping, une solution de triangulation discrète pour la surface complète de l'environnement intérieur. L’algorithme tente d'approximer le maillage surfacique en déformant et en collant la surface affinée du dodécaèdre sur le nuage de points numérisé. Le dernier module de cette mission de recherche consiste à développer des outils de l'extraction automatique / semi-automatique de plans architecturaux 2D à partir de la reconstruction 3D de la scène scannée. Ce processus d'extraction est possible à partir du nuage de points 3D ou du maillage en définissant un plan de coupe
Scene reconstruction is the process of building an accurate geometric model of one's environment from We explore the problem of complete scene reconstruction in indoor environments using mixed - data from the low-cost RGB-D camera and the inertial unit. The scanning process is realized in real-time, on the move with 6DoF of the numerizing system. We focus on computationally-constrained mobile systems, such as smartphone or tablet devices. Problematic issues present a set of fundamental challenges - estimating the state and trajectory of the device as it moves while scanning environment and utilizing lightweight data structures to hold the representation of the reconstructed scene. The system needs to be computationally and memory-efficient, so that it can run in real time, on-board the mobile device. The point-cloud resulted in the above module, which is non-structured and noisy cause of the quality of the low-cost sensor, needed a new method for the surface reconstruction. Our Dodecahedron Mapping is presented like a triangulation solution for the completed indoor environment scanning. After filtering and smoothing the point cloud, the algorithm tries to approximating the surface mesh by deforming and pasting the dodecahedron surface to the scanned point cloud. And the last stage of this research mission is to developing tools for the automatic extraction of 2D architectural plans from the 3D scanned building scene. This extracting process is also possible from the 3D point cloud or mesh by defining a section plane

Small kinematics assumption in classical engineering has been in the center of consideration in structural analysis for decennaries. In the recent years the interest for sustainable and optimized structures, lightweight structures and new materials has grown rapidly as a consequence of desire to archive economical sustainability. These issues involve non-linear constitutive response of materials and can only be accessed on the basis of geometrically and materially non-linear analysis. Numerical simulations have become a conventional tool in modern engineering and have proven accuracy in computation and are on the verge of superseding time consuming and costly experiments.\newlineConsequently, this work presents a numerical computational framework for modeling of geometrically non-linear large deformation of isotropic and orthotropic materials under static and dynamic loading. The numerical model is applied on isotropic steel in plane strain and orthotropic wood in 3D under static and dynamic loading. In plane strain Total Lagrangian, Updated Lagrangian, Newmark-$\beta$ and Energy Conserving Algorithm time-integration methods are compared and evaluated. In 3D, a Total Lagrangian static approach and a Total Lagrangian based dynamic approach with Newmark-$\beta$ time-integration method is proposed to numerically predict deformation of wood under static and dynamic loading. The numerical model's accuracy is validated through an experiment where a knot-free pine wood board under large deformation is studied. The results indicate accuracy and capability of the numerical model in predicting static and dynamic behaviour of wood under large deformation. Contrastingly, classical engineering solution proves its inaccuracy and incapability of predicting kinematics of the wood board under studied conditions.
Små kinematikantaganden inom klassisk ingenjörsteknik har varit centralt för konstruktionslösningar under decennier. Under de senaste åren har intresset för hållbara och optimerade strukturer, lättviktskonstruktioner och nya material ökat kraftigt till följd av önskan att uppnå ekonomisk hållbarhet. Dessa nya konstruktionslösningar involverar icke-linjär konstitutiv respons hos material och kan endast studeras baserad på geometriskt och materiellt olinjär analys. Numeriska simuleringar har blivit ett konventionellt verktyg inom modern ingenjörsteknik och visat sig ge noggrannhet i beräkning och kan på sikt ersätta tidskrävande och kostsamma experiment.\newlineDetta examensarbete presenterar ett numeriskt beräkningsramverk för modellering av geometrisk olinjäritet med stora deformationer hos isotropa och ortotropa material vid statisk och dynamisk belastning. Den numeriska modellen appliceras på isotropiskt stål i plantöjning och ortotropisk trä i 3D vid statisk och dynamisk belastning. I fallet med plantöjning jämförs och utvärderas den Totala Lagrangianen, Uppdaterade Lagrangianen, Newmark-$\beta$ och Energi Konserverings Algoritm metoderna. I 3D föreslås en statisk Total Lagrangian metod och en dynamisk Total Lagrangian-baserad metod med Newmark-$\beta$ tidsintegreringsmetod för att numeriskt förutse statisk och dynamisk deformation hos trä. Den numeriska modellens noggrannhet valideras genom ett experiment där en kvistfri furuplanka studeras under stora deformationer. Resultaten bekräftar noggrannhet och förmåga hos den numeriska modellen att förutse statiska och dynamiska processer hos trä vid stora deformationer. Däremot, visar klassisk ingenjörslösning brist på förmåga att förutse trä plankans kinematik under studerade förhållanden.

Les modélisations 3D de ville se multiplient à travers le monde et deviennent aujourd’hui accessibles grâce à la volonté des communes de les proposer librement. Il est ainsi aujourd’hui possible d’accéder à plusieurs milliers de kilomètres carrés de territoires urbains modélisés en 3D. Nous présentons dans cette thèse un ensemble de méthodes permettant d’enrichir un modèle virtuel 3D de ville, de l’organiser afin de faciliter son utilisation, puis de l’analyser en détectant les changements entre deux millésimes ou en mesurant son ambiance visuelle selon les besoins de l’utilisateur. Nous proposons dans un premier temps un algorithme permettant de compléter un modèle 3D en y adjoignant une définition sémantique grâce au cadastre, ainsi qu’une méthode de calcul de la canopée végétale 3D par croisement de données. Puis nous proposons des stratégies d’organisation du modèle 3D de la ville selon des critères géométriques et sémantiques afin de faciliter son parcours. Nous présentons ensuite des méthodes comparant deux millésimes de données représentant un même territoire dans le but de produire un unique modèle temporel contenant un ensemble de versions. Enfin, nous cherchons à mesurer l’ambiance visuelle de la ville via l’analyse de la composition d’un champ de vision ainsi que de l’ensoleillement et des ombres portées présentes sur un territoire. Ces mesures peuvent être liées à des données externes afin de proposer de multiples interprétations en fonction des besoins de l’utilisateur.Tous ces travaux se font dans un contexte d’interopérabilité et de généricité puisqu’ils ont pour objectif de pouvoir être utilisés avec des jeux de données provenant du monde entier. Nous basons donc nos méthodes sur l’utilisation de standards internationaux aussi bien pour les données en entrée que pour les résultats en sortie. Il est ainsi possible, dans le cadre d’une approche voulue dans un contexte de pluralité scientifique au sein du LabEx IMU, de mettre à disposition de la communauté les résultats mais aussi nos algorithmes proposés au sein d’un logiciel développé en open source
3D virtual models of cities are multiplying throughout the world and now become accessible thanks to the will of the communes to propose them freely. Today, it is possible to access several thousand square kilometres of urban territories modelled in 3D.We present in this thesis a set of methods to enrich a 3D virtual city model, organize it to facilitate its use and then analyse it by detecting changes between two vintages or by measuring its visual atmosphere according to the user’s needs. We first propose an algorithm to complete a 3D model by adding a semantic definition thanks to the cadastre, and a method to compute the 3D plant canopy by crossing data. Then we propose strategies to organize the 3D model of the city according to geometric and semantic criteria in order to facilitate its browsing. We then present methods comparing two vintages of data representing the same territory in order to produce a single temporal model containing a set of versions. Finally, we try to measure the visual atmosphere of the city by analysing the composition of a field of vision as well as the amount of sunshine and the shadows on a territory. These measurements can be linked to external data in order to propose multiple interpretations according to the user’s needs.All this work is done in a context of interoperability and genericity since it aims to be used with datasets from all over the world. We therefore base our methods on the use of international standards for both input and output data. It is thus possible, in a context of scientific plurality within the LabEx IMU, to make available to the community the results but also our algorithms proposed within an open source developed software

Les analyses structurale et mécanique des pentes rocheuses constituent des éléments clés pour l'évaluation de leur stabilité. L'utilisation complémentaire de la photogrammétrie et des modèles numériques qui couplent les réseaux discrets de discontinuités (DFN selon son sigle en anglais) avec la méthode des éléments discrets (DEM selon son sigle en anglais), présente une méthodologie qui peut être utilisée pour évaluer le comportement mécanique des configurations tridimensionnelles de terrain pour lesquelles l'existence de discontinuités non persistantes peut être supposée. La stabilité des masses rocheuses est généralement supposée être contrôlée par la résistance au cisaillement le long des plans de discontinuité. Si les discontinuités sont non persistantes, avec leur continuité interrompue par la présence de ponts rocheux (portions de roche intacte reliant la masse rocheuse au massif), leur résistance apparente augmente considérablement. Dans ce cas, la contribution des ponts rocheux localisés entre ces discontinuités doit être prise en compte dans l'analyse de stabilité. La déstabilisation progressive des massifs rocheux dans lesquels des discontinuités non persistantes sont présentes, peut être étudiée par des simulations numériques réalisées à l'aide de l'approche DEM. La roche intacte est représentée comme un assemblage de particules (ou éléments discrets) liées entre elles par des contacts dont les lois de comportement spécifiques peuvent être calibrées pour représenter correctement le comportement de la roche. L'intérêt de la méthode est qu'elle permet de simuler l'initiation de la rupture et sa propagation à l'intérieur de la matrice rocheuse du fait de la rupture des contacts cohésifs entre les particules. De plus, les discontinuités préexistantes peuvent être prises en compte explicitement dans le modèle en utilisant une loi de contact ad hoc qui assure un comportement mécanique représentatif des plans de discontinuité. Des analyses de stabilité ont été effectuées et ont mis en évidence le rôle des ponts rocheux dans la génération de nouvelles surfaces de rupture qui peuvent se développer à travers des mécanismes de rupture mixte en traction et en cisaillement. On peut considérer la formulation de Jennings comme l'une des premières méthodes d'analyse de la stabilité des pentes rocheuses qui évaluent la résistance au glissement comme une combinaison pondérée des résistances mécaniques des ponts rocheux et des plans de discontinuité. Sa validité a été discutée et systématiquement comparée aux résultats obtenus à partir de simulations numériques. Il a pu être montré que la formulation de Jennings perd sa validité dès que la rupture des ponts rocheux intervient majoritairement par des mécanismes de traction. Une formulation complémentaire a alors été proposée. En ce qui concerne l'étude de la stabilité des massifs rocheux sur site, il a été montré que l'association entre les données issues de la photogrammétrie en haute résolution et l'approche DFN-DEM peut être utilisée pour identifier des scénarios de rupture. L'analyse en retour de cas réels a montré que les surfaces de rupture peuvent être simulées comme le résultat de mécanismes combinant la fracturation des ponts rocheux et le glissement le long des discontinuités préexistantes. La rupture d'un dièdre qui a eu lieu dans une mine de charbon australienne, a été utilisée pour valider cette méthodologie. Des simulations numériques ont été réalisées pour déterminer les scénarios pour lesquels les surfaces de rupture simulées et celles repérées sur le terrain, peuvent être utilisés pour calibrer les paramètres de résistance du modèle numérique. Le travail présenté ici répond à un besoin plus général visant à améliorer la gestion des risques naturels et miniers liés aux masses rocheuses instables. La méthodologie proposée constitue une alternative robuste dédiée à renforcer la fiabilité des analyses de stabilité pour les pentes rocheuses fracturées à structure complexe
Structural and mechanical analyses of rock mass are key components for rock slope stability assessment. The complementary use of photogrammetric techniques and numerical models coupling discrete fracture networks (DFN) with the discrete element method (DEM) provides a methodology that can be applied to assess the mechanical behaviour of realistic three-dimensional (3D) configurations for which fracture persistence cannot be assumed. The stability of the rock mass is generally assumed to be controlled by the shear strength along discontinuity planes present within the slope. If the discontinuities are non–persistent with their continuity being interrupted by the presence of intact rock bridges, their apparent strength increases considerably. In this case, the contribution of the rock bridges located in-between these discontinuities have to be accounted for in the stability analysis. The progressive failure of rock slope involving non–persistent discontinuities can be numerically investigated based upon simulations performed using a DEM approach. The intact material is represented as an assembly of bonded particles interacting through dedicated contact laws that can be calibrated to properly represent the behaviour of the rock material. The advantage of the method is that it enables to simulate fracture initiation and propagation inside the rock matrix as a result of inter-particle bond breakage. In addition, pre–existing discontinuities can be explicitly included in the model by using a modified contact logic that ensures an explicit and constitutive mechanical behaviour of the discontinuity planes. Stability analyses were carried out with emphasis on the contribution of rock bridges failure through a mixed shear-tensile failure process, leading to the generation of new failure surfaces. Jennings' formulation being considered to be one of the first rock slope stability analysis that evaluates the resistance to sliding as a weighted combination of both, intact rock bridges and discontinuity planes strengths, its validity was discussed and systematically compared to results obtained from numerical simulations. We demonstrate that the validity of Jennings' formulation is limited as soon as tensile failure becomes predominant and an alternative formulation is proposed to assess the resulting equivalent strength. Regarding field slope stability, we show that the combination of high resolution photogrammetric data and DFN-DEM modelling can be used to identify valid model scenarios of unstable wedges and blocks daylighting at the surface of both natural and engineered rock slopes. Back analysis of a real case study confirmed that failure surfaces can be simulated as a result of both fracture propagation across rock bridges and sliding along pre-existing discontinuities. An identified wedge failure that occurred in an Australian coal mine was used to validate the methodology. Numerical simulations were undertaken to determine in what scenarios the measured and predicted failure surfaces can be used to calibrate strength parameters in the model. The work presented here is part of a more global need to improve natural and mining hazards management related to unstable rock masses. We believe that the proposed methodology can strengthen the basis for a more comprehensive stability analysis of complex fractured rock slopes

Le canal de propagation est un élément important pour la fiabilité des simulations et la conception des systèmes sans fil. Les modèles déterministes offrent un bon niveau de précision au prix d'une complexité croissante de calcul, ce qui les rend prohibitifs pour les simulateurs de réseaux de capteurs sans fil (RdC) car ils impliquent de nombreux nœuds distribués à l'échelle d’une ville. Dans ce contexte, l'objectif de cette thèse est de proposer des méthodes déterministes rapides et précises pour modéliser le comportement des ondes électromagnétiques en garantissant le juste compromis entre la précision et le temps de calcul. L’étude a d’abord été subdivisée en deux modes selon le mécanisme dominant de propagation. Dans une configuration microcellule, l'approche proposée est basée sur un modèle de lancer de rayons reposant sur la technique de la visibilité qui adopte un ensemble de techniques d'accélération pour réduire la complexité sans perte significative de la précision. Dans le même objectif, la propagation verticale a été abordée en incluant les contributions les plus significatives. Enfin, ces modèles ont été intégrés dans un simulateur de RdC pour fournir des résultats réalistes dans le contexte d'une ‘smart city’. L'impact des modèles précis dans les simulateurs est illustré par certains paramètres du réseau
Modeling the radio channel in an accurate way is a key element of any wireless systems. Deterministic models offer a good degree of precision at the cost of high computational complexity, which is prohibitive for wireless sensor network (WSN) simulators because they involve many sensor nodes in a city-wide scale. Within this context, the objective of this thesis is to propose efficient, fast, and accurate deterministic methods for modeling electromagnetic waves by finding the best time-accuracy trade-offs that guarantee accuracy under tight time constraints. The study was first subdivided into two modes according to the dominant propagation mechanism. In microcell configurations, the proposed approach is a ray-tracing model based on the visibility technique. It adopts a set of acceleration techniques to reduce the complexity with a minimal loss of precision. With the same objective, the vertical propagation was addressed to include the most significant contributions. Finally, these models were integrated into a WSN simulator to provide realistic and accurate results for smart city applications. The importance of using accurate models in WSN simulators is illustrated in terms of some network parameters

De nombreux bâtiments anciens sont à rénover pour diminuer leur consommation énergétique. Grâce à l'émergence d’outils numériques tels que la maquette numérique d'un bâtiment ou BIM (Building Information Modeling), des simulations énergétiques peuvent être réalisées. Or, pour la plupart des bâtiments, aucune information numérique n'est disponible. L'objectif de nos travaux est de développer une méthodologie pour générer des maquettes numériques de bâtiments existants à faible coût en limitant l'acquisition de données. Notre choix s'est porté sur l'utilisation de plan papier 2D scanné. Nous faisons l'hypothèse qu'un tel plan est presque toujours disponible pour un bâtiment même s’il n'est pas toujours à jour et que sa qualité influe sur celle de la reconstruction. La reconstruction automatique d'un BIM à partir d'une image se base sur la recherche et l'identification de 3 composantes: la géométrie (forme des éléments), la topologie (liens entre les éléments) et la sémantique (caractéristiques des éléments). Lors de cette phase, des ambiguïtés peuvent apparaître. Nous proposons un processus basé sur des interventions ponctuelles et guidées de l'utilisateur afin d'identifier les erreurs et proposer des choix de correction pour éviter leur propagation.Nous présentons la méthodologie développée pour proposer une reconstruction semi-automatique et une analyse des résultats obtenus sur une base de 90 plans. Les travaux ont ensuite porté sur une généralisation du processus afin d'en tester la robustesse, le passage à l'échelle et la gestion multi-niveaux. Le processus développé est flexible pour permettre l’ajout d'autres sources de données pour enrichir la maquette numérique
Many buildings have to undergo major renovation to comply with regulations and environmental challenges. The BIM (Building Information Modeling) helps designers to make better-informed decisions, and results in more optimal energy-efficient designs. Such advanced design approaches require 3D digital models. However such models are not available for existing buildings. The aim of our work is to develop a method to generate 3D building models from existing buildings at low cost and in a reasonable time. We have chosen to work with 2D scanned plans. We assume that it is possible to find a paper plan for most buildings even if it is not always up-to-date and if the recognition quality is also dependent to the plan. The automatic reconstruction of a BIM from a paper plan is based on the extraction and identification of 3 main components: geometry (element shape), topology (links between elements) and semantics (object properties). During this process, some errors are generated which cannot be automatically corrected. This is why, we propose a novel approach based on punctual and guided human interventions to automatically identify and propose correction choices to the user to avoid error propagation.We describe the developed methodology to convert semi-automatically a 2D scanned plan into a BIM. A result analysis is done on 90 images. The following works is focused on the process genericity to test its robustness, the challenge of moving to scale and the multi-level management. The results highlight the pertinence of the error classification, identification and choices made to the user. The process is flexible in order to be completed by others data sources

L'objectif de nos travaux est de développer un cadre méthodique afin de modéliser les préférences, les changements de comportement des individus ainsi que leurs impacts sur l'état d'un système complexe dans un contexte dynamique. L'utilisateur doit simuler les conséquences des politiques de transports et d'urbanisme sur l'offre et demande de stationnement, étape essentielle. Modéliser les préférences hétérogènes des usagers, intégrer des connaissances, selon des logiques comportementales différentes, ont justifié l'approche multi agents. Afin d'avoir des représentations adaptatives et évolutives des comportements des agents individus, les processus décisionnels et d'apprentissage sont modélisés au moyen d'un panier d'outils issus de l'optimisation des procédés industriels, des techniques Data Mining, de marketing. L'emploi personnalisé du simulateur avec l'interactivité utilisateursimulateur a motivé l'adaptation de ce cadre méthodique à la simulation des systèmes complexes sociétaux.

Os dados geográficos têm um papel determinante na formalização do plano urbano, enquanto instrumento de planeamento e documento normativo que define juridicamente as obrigações públicas e vincula os particulares, num determinado período temporal, no que respeita a disciplina urbanística de uma cidade ou de um aglomerado urbano, estabelecendo regras de uso e de ocupação do solo. O plano está associado a um processo, designado processo de planeamento; processo esse que e constituído por um conjunto de fases, dinâmicas e adaptativas, que se iniciam na sua elaboração e terminam na avaliação dos desvios entre o determinado no documento inicial e as metas e objectivos efectivamente atingidos. O plano, o processo e a praxis do planeamento exigem dados geográficos actualizados a cada instante, quer para as acções de monitorização quer para os momentos de avaliação. Um dos aspectos cruciais do plano e a quantificação da volumetria do espaço edificado existente. Outro aspecto, também fundamental, é o da gestão dessa volumetria; quer da volumetria existente quer da volumetria adicional. O tema da volumetria dos espaços edificados tem constituído, aliás, um dos temas mais sensíveis quando se trata da densificação do espaço urbano existente ou do desenho de novos espaços urbanos de expansão. Considerando o quadro teórico apresentado, o tema central da tese trata da modelação de nuvens de pontos 3D obtidas por tecnologia LiDAR e por UAV, para as aplicações na elaboração do plano e no processo de planeamento urbano, designadamente quantificação dos parâmetros urbanísticos altura da fachada e volume dos edifícios.A exploração do tema central da tese suporta-se em dois níveis: o nível da operacionalização e o nível da usabilidade. O nível da operacionalizão concretiza dois objectivos: i) demonstração da relevância e da pertinência da extracção, medição e geovisualização 3D dos parâmetros urbanísticos baseadas na experimentação e implementação de técnicas de geoprocessamento; ii) demonstração da pertinência dos parâmetros urbanísticos extraídos considerando distintas morfologias urbanas. Para o nível da usabilidade de nem-se igualmente dois objectivos: i) demonstração da usabilidade dos parâmetros urbanísticos extraídos avaliando o erro associado a extracção; ii) demonstração da usabilidade dos parâmetros urbanísticos extraídos para planeamento, em particular para o mapeamento dasimétrico de alta precisão. Da investigação decorre uma solução metodol ogica. A solução metodológica nomeada 3D Extraction Building Parameters (3DEBP) destina-se a extracção da área, da altura da fachada e do volume dos edifícios a partir de nuvens de pontos 3D. Esta solução foi criada tendo por base um conjunto de ferramentas FOSS: PostgreSQL/PostGIS, QGIS, GRASS e R-stats. Foram realizados testes em duas áreas urbanas com morfologias distintas: Praia de Faro (morfologia irregular) e Amadora (morfologia regular). O teste sobre a área urbana da Praia de Faro utilizou uma nuvem de pontos LiDAR e uma outra extra da de levantamento realizado por UAV. O teste sobre um quarteirão urbano de Amadora foi realizado apenas sobre nuvem de pontos UAV. Os testes revelaram que a qualidade da informação extra da e dependente da morfologia urbana. Nas conclusões discute-se a medição 3D com base em dados obtidos por tecnologia LiDAR e UAV, questiona-se a implementação de soluções FOSS para diferentes fases do processo de planeamento e defende-se a introdução intensiva da modelação 3D no plano urbano do futuro.
Geographical data plays a major role in urban plan development, both as a planning instrument and as a normative document that legally de nes public obligations and binds individuals, in a given period of time, regarding the urban aspect of a city or an urban conglomerate, and establishes standards for land use and land cover. The plan is associated with a process, called the planning process, which consists in a set of dynamic and adaptive phases that begin with its development and end with the evaluation of any discrepancies between the provisions of the original document and the accomplished goals and objectives. The plan, the process, and the planning praxis require up-to-date geographical data at all times, both for monitoring actions and for the evaluation phases. One of the crucial aspects of the plan is the quanti cation of the existing building volume. Another fundamental aspect is managing that volume: both regarding the existing volume and any additional volumes. Actually, the building volume in built areas has been one of the most sensitive topics on the densi cation of existing urban spaces or the design of new growing urban areas. Considering the existing theoretical framework, the central topic of this thesis focuses on 3D point cloud modelling obtained from LiDAR and UAV technologies, employed in the development of a plan and in the urban planning process, namely regarding two speci c building parameters { building height and volume. The explanation of the central topic of this thesis is twofold: implementation and usability. The implementation level has two goals: i) demonstrating the relevance and pertinence of the extraction, measurement, and 3D geovisualization of building parameters based on the experimentation and implementation of geoprocessing techniques; ii) demonstrating the pertinence of the extracted building parameters considering di erent urban morphologies. At the usability level, we de ned two goals: i) demonstrating the usability of the extracted building parameters, evaluating the error associated with the extraction; ii) demonstrating the usability of these parameters for planning, particularly for high precision dasymetric mapping. Based on our research, we propose a methodological solution termed. 3D Extraction Building Parameters (3DEBP) and aimed at extracting areas, fa cade height, and building volumes from 3D point clouds. This solution was created with the following set of FOSS tools: PostgreSQL/PostGIS, GRASS, QGIS, and R-stats. We performed several tests in two urban areas with di erent morphologies: Praia de Faro (irregular morphology) and Amadora (regular morphology). The former (Praia de Faro) used a LiDAR point cloud and another one extracted from a UAV survey, while the latter (urban neighbourhood of Amadora) only used a UAV point cloud. Both experiments reveal that the quality of the information extracted depends on urban morphology. Finally, we discuss 3D measurement based on data obtained from LiDAR and UAV technology, raising questions on the implementation of FOSS solutions for di erent phases of the planning process, and arguing for the intensive introduction of 3D modelling for the future of urban planning.

Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.
The field of GIS has in recent years been increasingly demanding better 3d functionality and ever more resources is being spent in researching the concept. The work presented here is on the integration and use of procedural modeling language for generating a realistic 3d model of the University Jaume I in Castellón de la Plana Spain. The language used is a modified version of shape grammars combined with split grammars with the software CityEngine. The work is conducted with the use of CityEngine and is intended as a contribution to the currently active research on the use of shape grammar in GI science.The field of GIS has in recent years been increasingly demanding better 3d functionality and ever more resources is being spent in researching the concept. The work presented here is on the integration and use of procedural modeling language for generating a realistic 3d model of the University Jaume I in Castellón de la Plana Spain. The language used is a modified version of shape grammars combined with split grammars with the software CityEngine. The work is conducted with the use of CityEngine and is intended as a contribution to the currently active research on the use of shape grammar in GI science.

The master thesis deals with a block subdivision into parcels using procedural modeling. The main goal focuses on improving of the existing method called OBB-based Subdivision that uses auxiliary envelopes of rectangle shape for splitting. It is required to adapt the method to Czech conditions as well. The first part focuses on the analysis of scientific publications, which describes the development and current situation of procedural modeling issues. Then the methodology of suggested algorithm is described that tests a change of the envelope to the trapezium shape, respectively to the quadrangle shape. In conclusion, the proposed algorithms are tested on the real data in CityEngine, which offered the possibility of using procedural approach to automatically generate 3D parcels. The whole process is controlled by the limitations of development plans of the selected urban areas. Powered by TCPDF (www.tcpdf.org)