In the last fifteen years, the use of smartphones has exploded and almost everyone in the Nordic countries owns a smartphone that they use for everyday matters. With the rise of popularity in the usage of smartphones and not least their technical development, the number of applications to use them continues to increase. One area that smartphones can be used for is virtual reality (VR) and as this area has become more popular, the technology behind VR has become more and more sophisticated. Nowadays many smartphones are equipped with multiple cameras and LiDAR sensors that can be used by the device to create a virtual model of the physical environment. In this project, different methods were evaluated to use this virtual model to estimate the size of physical packages to add functionality to the PostNord consumer app for measuring packages when purchasing postage.

De nos jours, la majorité des objets manufacturés sont conçus par des logiciels informatiques de CAO (Conception Assistée par Ordinateur). Cependant, lors de la visualisation, d'échange de données ou des processus de fabrication, le modèle géométrique doit être discrétisé en un maillage 3D composé d'un nombre fini de sommets et d'arêtes. Or, dans certaines situations le modèle initial peut être perdu ou indisponible. La représentation discrète 3D peut aussi être modifiée, par exemple après une simulation numérique, et ne plus correspondre au modèle initial. Une méthode de rétro-ingénierie est alors nécessaire afin de reconstruire une représentation continue 3D à partir de la représentation discrète.Dans ce manuscrit, nous présentons une procédure automatique et complète de rétro-ingénierie pour les maillages 3D issus principalement de la discrétisation d'objets mécaniques. Pour cela, nous proposons des améliorations sur la détection de primitives géométriques simples. Puis, nous introduisons un formalisme clair pour la définition de la topologie de l'objet et la construction des intersections entre les primitives. Enfin, nous décrivons une nouvelle méthode de construction de surfaces paramétriques 3D, fondée sur l'extraction automatique de grilles rectangulaires régulières supports. La méthode a été testée sur des maillages 3D issus d'applications industrielles et permet d'obtenir des modèles B-Rep cohérents. / Nowadays, most of the manufactured objects are designed using CAD (Computer-Aided Design) software. Nevertheless, for visualization, data exchange or manufacturing applications, the geometric model has to be discretized into a 3D mesh composed of a finite number of vertices and edges. But, in some cases, the initial model may be lost or unavailable. In other cases, the 3D discrete representation may be modified, for example after a numerical simulation, and does not correspond anymore to the initial model. A retro-engineering method is then required to reconstruct a 3D continuous representation from the discrete one.In this Ph.D. Thesis, we present an automatic and comprehensive reverse engineering process mainly dedicated to 3D meshes of mechanical items. We present first several improvements in automatically detecting geometric primitives from a 3D mesh. Then, we introduce a clear formalism to define the topology of the object and to construct the intersections between primitives. At the end, we describe a new method to fit 3D parametric surfaces which is based on extracting regular rectangular grids. The whole process is tested on 3D industrial meshes and results in reconstructing consistent B-Rep models.

De nos jours la protection des données numériques est un problème très important. Que ce soit pour des applications de confidentialité, de communication, de traçabilité ou d'identification par exemple, il est nécessaire de développer des techniques adaptées. Dans le cadre de cette thèse en collaboration avec la société STRATEGIES S.A., la méthode choisie pour la protection de maillages 3D est l'insertion de données cachées, également appelée tatouage numérique. Pour des données 3D, un des problèmes les plus importants est la phase de synchronisation qui intervient dans les algorithmes d'insertion et d'extraction des données. Cette phase permet de repérer, de sélectionner et d'ordonner les « zones » qui sont privilégiées pour la dissimulation d'information. Nous avons choisi d'orienter le manuscrit sur cette phase. Ainsi, nous proposons une classification des méthodes de tatouages en fonction de leur méthode de synchronisation. Puis en se basant sur des techniques de synchronisation par des structures de données, telle que les arbres couvrants de poids minimum, nous proposons une analyse théorique de cette structure. Dans un premier temps nous expliquons les raisons de la sensibilité des arbres à la mobilité des points. Puis connaissant ses faiblesses, nous proposons une autre technique de synchronisation toujours basée sur les arbres couvrants de poids minimum. / Data security is one of the main issue in computer science. We need to develop solutions for confidentiality, communication, fingerprinting or identification applications for exemple. In this thesis made with STRATEGIES S.A., the chosen method to protect 3D meshes is watermarking.Watermarking is divided in two steps, the embedding and the extraction. In both of them a synchronization phase is needed. It is one of the most important step for 3D mesh because it permits to look for areas available to embed information, and order them. All the thesis is devoted to the synchronization step. First of all, we propose a classification of watermarking techniques based on the type of synchronization method instead of evaluation criterions such as robustness or capacity.Then, from methods based on Euclidean minimum spanning tree, we propose a theoritical analysis of the mobility of the vertices in that kind of structure. First, we explain the reasons of the sensibility of the structure. Secondly, we propose another scheme based on the Euclidean minimum spanning tree knowing its fragility.

This thesis relates to research and development in the field of 3D mesh data for computer graphics. A review of existing storage and manipulation techniques for mesh data is given followed by a framework for mesh editing. The proposed framework combines complex mesh editing techniques, automatic level of detail generation and mesh compression for storage. These methods work coherently due to the underlying data structure. The problem of storing and manipulating data for 3D models is a highly researched field. Models are usually represented by sparse mesh data which consists of vertex position information, the connectivity information to generate faces from those vertices, surface normal data and texture coordinate information. This sparse data is sent to the graphics hardware for rendering but must be manipulated on the CPU. The proposed framework is based upon geometry images and is designed to store and manipulate the mesh data entirely on the graphics hardware. By utilizing the highly parallel nature of current graphics hardware and new hardware features, new levels of interactivity with large meshes can be gained. Automatic level of detail rendering can be used to allow models upwards of 2 million polygons to be manipulated in real time while viewing a lower level of detail. Through the use of pixels shaders the high detail is preserved in the surface normals while geometric detail is reduced. A compression scheme is then introduced which utilizes the regular structure of the geometry image to compress the floating point data. A number of existing compression schemes are compared as well as custom bit packing. This is a TIF funded project which is partnered with Unlimited Realities, a Palmerston North software development company. The project was to design a system to create, manipulate and store 3D meshes in a compressed and easy to manipulate manner. The goal is to create the underlying technologies to allow for a 3D modelling system to become integrated into the Umajin engine, not to create a user interface/stand alone modelling program. The Umajin engine is a 3D engine created by Unlimited Realities which has a strong focus on multimedia. More information on the Umajin engine can be found at www.umajin.com. In this project we propose a method which gives the user the ability to model with the high level of detail found in packages aimed at creating offline renders but create models which are designed for real time rendering.

This thesis examines an automated method to detect surface deformations on automotive panels for the purpose of quality control along a manufacturing assembly line. Automation in the automotive manufacturing industry is becoming more prominent, but quality control is still largely performed by human workers. Quality control is important in the context of automotive body panels as deformations can occur along the assembly line such as inadequate handling of parts or tools around a vehicle during assembly, rack storage, and shipping from subcontractors. These defects are currently identified and marked, before panels are either rectified or discarded. This work attempts to develop an automated system to detect deformations to alleviate the dependence on human workers in quality control and improve performance by increasing speed and accuracy. Some techniques make use of an ideal CAD model behaving as a master work, and panels scanned on the assembly line are compared to this model to determine the location of deformations. This thesis presents a solution for detecting deformations of various scales without a master work. It also focuses on automated analysis requiring minimal intuitive operator-set parameters and provides the ability to classify the deformations as dings, which are deformations that protrude from the surface, or dents, which are depressions into the surface. A complete automated deformation detection system is proposed, comprised of a feature extraction module, segmentation module, and classification module, which outputs the locations of deformations when provided with the 3D mesh of an automotive panel. Two feature extraction techniques are proposed. The first is a general feature extraction technique for 3D meshes using octrees for multi-resolution analysis and evaluates the amount of surface variation to locate deformations. The second is specifically designed for the purpose of deformation detection, and analyzes multi-resolution cross-sections of a 3D mesh to locate deformations based on their estimated size. The performance of the proposed automated deformation detection system, and all of its sub-modules, is tested on a set of meshes which represent differing characteristics of deformations in surface panels, including deformations of different scales. Noisy, low resolution meshes are captured from a 3D acquisition, while artificial meshes are generated to simulate ideal acquisition conditions. The proposed system shows accurate results in both ideal situations as well as non-ideal situations under the condition of noise and complex surface curvature by extracting only the deformations of interest and accurately classifying them as dings or dents.

This thesis examines an automated method to detect surface deformations on automotive panels for the purpose of quality control along a manufacturing assembly line. Automation in the automotive manufacturing industry is becoming more prominent, but quality control is still largely performed by human workers. Quality control is important in the context of automotive body panels as deformations can occur along the assembly line such as inadequate handling of parts or tools around a vehicle during assembly, rack storage, and shipping from subcontractors. These defects are currently identified and marked, before panels are either rectified or discarded. This work attempts to develop an automated system to detect deformations to alleviate the dependence on human workers in quality control and improve performance by increasing speed and accuracy. Some techniques make use of an ideal CAD model behaving as a master work, and panels scanned on the assembly line are compared to this model to determine the location of deformations. This thesis presents a solution for detecting deformations of various scales without a master work. It also focuses on automated analysis requiring minimal intuitive operator-set parameters and provides the ability to classify the deformations as dings, which are deformations that protrude from the surface, or dents, which are depressions into the surface. A complete automated deformation detection system is proposed, comprised of a feature extraction module, segmentation module, and classification module, which outputs the locations of deformations when provided with the 3D mesh of an automotive panel. Two feature extraction techniques are proposed. The first is a general feature extraction technique for 3D meshes using octrees for multi-resolution analysis and evaluates the amount of surface variation to locate deformations. The second is specifically designed for the purpose of deformation detection, and analyzes multi-resolution cross-sections of a 3D mesh to locate deformations based on their estimated size. The performance of the proposed automated deformation detection system, and all of its sub-modules, is tested on a set of meshes which represent differing characteristics of deformations in surface panels, including deformations of different scales. Noisy, low resolution meshes are captured from a 3D acquisition, while artificial meshes are generated to simulate ideal acquisition conditions. The proposed system shows accurate results in both ideal situations as well as non-ideal situations under the condition of noise and complex surface curvature by extracting only the deformations of interest and accurately classifying them as dings or dents.

This thesis examines an automated method to detect surface deformations on automotive panels for the purpose of quality control along a manufacturing assembly line. Automation in the automotive manufacturing industry is becoming more prominent, but quality control is still largely performed by human workers. Quality control is important in the context of automotive body panels as deformations can occur along the assembly line such as inadequate handling of parts or tools around a vehicle during assembly, rack storage, and shipping from subcontractors. These defects are currently identified and marked, before panels are either rectified or discarded. This work attempts to develop an automated system to detect deformations to alleviate the dependence on human workers in quality control and improve performance by increasing speed and accuracy. Some techniques make use of an ideal CAD model behaving as a master work, and panels scanned on the assembly line are compared to this model to determine the location of deformations. This thesis presents a solution for detecting deformations of various scales without a master work. It also focuses on automated analysis requiring minimal intuitive operator-set parameters and provides the ability to classify the deformations as dings, which are deformations that protrude from the surface, or dents, which are depressions into the surface. A complete automated deformation detection system is proposed, comprised of a feature extraction module, segmentation module, and classification module, which outputs the locations of deformations when provided with the 3D mesh of an automotive panel. Two feature extraction techniques are proposed. The first is a general feature extraction technique for 3D meshes using octrees for multi-resolution analysis and evaluates the amount of surface variation to locate deformations. The second is specifically designed for the purpose of deformation detection, and analyzes multi-resolution cross-sections of a 3D mesh to locate deformations based on their estimated size. The performance of the proposed automated deformation detection system, and all of its sub-modules, is tested on a set of meshes which represent differing characteristics of deformations in surface panels, including deformations of different scales. Noisy, low resolution meshes are captured from a 3D acquisition, while artificial meshes are generated to simulate ideal acquisition conditions. The proposed system shows accurate results in both ideal situations as well as non-ideal situations under the condition of noise and complex surface curvature by extracting only the deformations of interest and accurately classifying them as dings or dents.

L'évolution biologique des organismes peut être étudiée comme une succession de transformations morphologiques qui sont caractérisées par le changement de leur géométrie tridimensionnelle globale et locale. Dans ce contexte, il est nécessaire de développer des outils mathématiques et informatiques comparatifs de formes tridimensionnelles afin d'étudier ces transformations et de pouvoir les comparer avec les variabilités inter- et intra-espèces. Dans la chaîne de traitement des données tridimensionnelles (images 3D ou maillages 3D) employée en " paléoanthropologie virtuelle ", la méthode la plus souvent utilisée en analyse comparative est basée sur des points de repère (en général, anatomiques) dont les coordonnées sont analysées à l'aide d'outils mathématiques tels que la " morphométrie géométrique ". Plus récemment, une autre classe de méthodes a été proposée. Elle permet des comparaisons globales entre les surfaces complètes de structures anatomiques sans avoir besoin de définir des points de repère. On obtient ainsi une analyse statistique de la forme moyenne et de sa variabilité en tout point. Dans cette thèse, nous proposons d'étudier la chaîne d'analyse morphométrique des données 3D utilisées en paléoanthropologie, de la numérisation à l'exploitation des données par les chercheurs. Cette thèse présente des méthodes analytiques pour le traitement des données issues de la paléoanthropologie, depuis la numérisation des sites de fouilles jusqu'à l'acquisition et l'analyse des spécimens. Nous établissons des modèles numériques de terrain (analyses multidimensionnelles de données issues de différentes modalités d'acquisition telles que les scans laser et la photogrammétrie) qui permettent d'appréhender les vestiges dans leur contexte et nous proposons des analyses qui répondent à des problématiques qui sont spécifiques aux études en biologie. En particulier, nous apportons des outils d'analyse et de visualisation (cartographies 3D et analyses statistiques) pour des problématiques de déformation basées sur des recalages surfaciques. Nous proposons également une méthode d'analyse sur des données partielles afin de pouvoir exploiter l'ensemble des données disponibles dans les registres fossiles et modernes. Nos résultats mettent en évidence que les méthodes par recalage surfacique augmentent non seulement les possibilités de capter les formes et leurs variations, mais permettent également de travailler sur des formes globales et non uniquement sur certains points. Nous montrons notamment que ces méthodes permettent le développement d'outils qui sont bien adaptés pour les études en paléoanthropologie. / The biological evolution of organisms can be studied as a set of morphological transformations which are characterized by the modification of their global three- dimensional geometry and by some discrete traits. In this context, it is necessary to develop comparative mathematical and computational tools for the study of the inter- and intraspecific variation. Within the three-dimensional data processing workflow (3D images or 3D meshes) employed in " virtual paleoanthropology ", the method that is most commonly used in comparative analysis is based on landmarks (most often anatomical landmarks) from which coordinates are analyzed by using mathematical tools such as " geometric morphometrics ". More recently, other methods allowing global comparisons between three-dimensional reconstructions without landmarks have been proposed. They allow for example the statistical analysis of a global shape and its variability. We suggest to study the process for morphometric analysis of 3D data commonly used in paleoanthropology, from the digitization to the exploration of 3D data. This dissertation introduces analytical methods for the processing of data provided by paleoanthropological studies, from the digitization of the excavation sites to the acquisition and the analysis of specimens. We established digital ground models (multidimensional analyses of data from various modalities of acquisition such as laser scanner and photogrammetry) that contribute to a comprehensive understanding of fossil remains in their context and we proposed relevant analyses for resolving specific problems inherent to biological studies. In particular, we developed appropriate tools for analyses and viewing (3D mappings and statistical analyses) dedicated specifically to problems of deformation-based registrations. Additionally, we introduced a method for the analysis of partial data in order to use all the specimens available in the fossil and modern records. Besides opening up new possibilities of capturing shape variation, our results highlight that techniques based on surface registration provide a reliable methodological framework for working on global shapes without focusing on specific points. We reported in particular that these methods allow the development of tools which are particularly suitable for the paleoanthropological studies.

This thesis examines an automated method to detect surface deformations on automotive panels for the purpose of quality control along a manufacturing assembly line. Automation in the automotive manufacturing industry is becoming more prominent, but quality control is still largely performed by human workers. Quality control is important in the context of automotive body panels as deformations can occur along the assembly line such as inadequate handling of parts or tools around a vehicle during assembly, rack storage, and shipping from subcontractors. These defects are currently identified and marked, before panels are either rectified or discarded. This work attempts to develop an automated system to detect deformations to alleviate the dependence on human workers in quality control and improve performance by increasing speed and accuracy. Some techniques make use of an ideal CAD model behaving as a master work, and panels scanned on the assembly line are compared to this model to determine the location of deformations. This thesis presents a solution for detecting deformations of various scales without a master work. It also focuses on automated analysis requiring minimal intuitive operator-set parameters and provides the ability to classify the deformations as dings, which are deformations that protrude from the surface, or dents, which are depressions into the surface. A complete automated deformation detection system is proposed, comprised of a feature extraction module, segmentation module, and classification module, which outputs the locations of deformations when provided with the 3D mesh of an automotive panel. Two feature extraction techniques are proposed. The first is a general feature extraction technique for 3D meshes using octrees for multi-resolution analysis and evaluates the amount of surface variation to locate deformations. The second is specifically designed for the purpose of deformation detection, and analyzes multi-resolution cross-sections of a 3D mesh to locate deformations based on their estimated size. The performance of the proposed automated deformation detection system, and all of its sub-modules, is tested on a set of meshes which represent differing characteristics of deformations in surface panels, including deformations of different scales. Noisy, low resolution meshes are captured from a 3D acquisition, while artificial meshes are generated to simulate ideal acquisition conditions. The proposed system shows accurate results in both ideal situations as well as non-ideal situations under the condition of noise and complex surface curvature by extracting only the deformations of interest and accurately classifying them as dings or dents.

The goal of this thesis is to scan part of castle Rokštejn using terrestrial laser scanner and from obtained data draw up a 3D model. Model is made with a method using meshing. In this work I also deal with the software, which supports meshing, and evaluating pros and cons of each program. The output of this work is 3D model which will serve to better representation of the current state of the castle and its better documentation.