Procedural modeling is a powerful technique used in computer graphics to create geometric models. Instead of manual geometry definition, models are generated implicitly from a set of rules and parameters. Procedural systems have found widespread use in generating content for games, film, and simulation of natural phenomena. Their strength comes from the ability to automatically generate large amount of varied geometry. One of their drawbacks is lack of control because a small change in input parameters often causes large changes in the generated model. <br>In this work we present three novel procedural systems, investigate different forms of control, namely simulation and optimization, and discuss them in terms of general procedural modeling workflow. First we show modeling of 3D objects with arbitrary topology via erosion and deposition simulation controlled by Smoothed Particle Hydrodynamics. Next, we present an algorithm for generating 3D curves using 2D sketches and contextual geometry. Finally, we propose a novel procedural system capable of generating arbitrary type of geometry with respect to user-defined constraints. <br>We show that these systems can be controlled via several means and identify common preconditions that facilitate control: maximizing interactivity and amount of structured information input, minimizing unexpected behaviour, and local control akin to traditional modeling.

Dans cette thèse, nous proposons une approche combinatoire novatrice fondée sur les matroïdes orientés pour l'étude quantitative de la forme de structures anatomiques 3D. Nous nous basons sur des points de repère qui ont été préalablement localisés par des experts sur la structure anatomique étudiée. La nouveauté de cette méthode provient de l'utilisation de matroïdes orientés. Ces outils mathématiques nous permettent de coder la position relative des points de repère de façon purement combinatoire, c'est-à-dire sans utiliser de notions d'angles ou de distances, en associant un signe (0, + ou -) à chaque sous-ensemble de (d+1) points de repère où d est la dimension de l'espace (dans notre cas 2 ou 3). Dans une première partie, nous supposons qu'il existe des contraintes d'ordres sur chaque axe de coordonnée pour les points de repère. Nous obtenons alors une caractérisation (en dimension 2 et 3) des sous-ensembles de points de repère dont le signe associé est constant, quelles que soient les valeurs des coordonnées satisfaisant les contraintes d'ordre. Dans une deuxième partie, nous cherchons à classifier un ensemble de modèles 3D, en les codant au préalable par ces listes de signes. Nous analysons d'abord comment s'appliquent les algorithmes de clustering classiques, puis nous décrivons comment caractériser des classes de façon directe, à l'aide des signes associés à quelques sous-ensembles de points de repère. Dans une troisième partie, nous détaillons les algorithmes et l'implémentation en machine de cette nouvelle méthode de morphométrie afin de pouvoir l'appliquer à des données réelles. Dans la dernière partie, nous appliquons la méthode sur trois bases de données composées chacune de plusieurs dizaines de points de repères relevés sur plusieurs dizaines à plusieurs centaines de structures crâniennes pour des applications en anatomie comparée, en orthodontie et sur des cas cliniques d'enfants présentant des déformations cranio-faciales. / In this thesis, we propose an innovative combinatorial method based on oriented matroids for the quantitative study of the shape of 3D anatomical structures. We rely on landmarks which were previously defined by experts on the studied anatomical structure. The novelty of this method results from the use of oriented matroids. These mathematical tools allow us to encode the relative position of landmarks in a purely combinatorial way, that is without using concepts of angles or distances, by associating a sign (0, + or -) for each subset of (d+1) landmarks where d is the dimension of space (in our case 2 or 3). In the first part, we assume that there exist constraints of orders on each coordinate axis for the landmarks. We obtain a characterization (in dimension 2 and 3) of the subsets of landmarks of which the associated sign is constant, regardless of the values of the coordinates satisfying the constraints of order. In a second part, we try to classify a set of 3D models, encoding in advance by these lists of signs. We first analyze how to apply classic clustering algorithms, and then describe how to characterize the classes directly, using signs associated with some subsets of landmarks. In the third part, we explain the algorithms and the implementation of this new morphometry method in order to apply it to real data. In the last part, we apply the method to three databases each consisting of several dozens of points defined on several dozens to several hundreds of cranial structures for applications in comparative anatomy, in orthodontics and on clinical cases of children with craniofacial deformities.

The focus of this thesis is to find the most modern methods to craft 3D characters for implementation in game engines. The industry is constantly adapting to new software and my study is to cover the most efficient way to create a character from an idea to fully realized character in 3D. The following is my journey in learning new techniques and adapting to the new software. To demonstrate, I will work through the process of creating a character from a 2D concept to a 3D model rendered in real time.

The Uluburun shipwreck was discovered in 1982 when a Turkish sponge diver informed the Institute of Nautical Archaeology (INA) of his discovery of metal biscuits with ears. INA archaeologists recognized this as a description of oxhide ingots, a clear indication of a Late Bronze Age site. This find was of considerable interest as very little is known about seafaring, long distance trade, and ship construction during the Late Bronze Age, except for a glimpse provided by the Cape Gelidonya shipwreck excavated in 1960 by George Bass. The site at Uluburun revealed only a handful of disarticulated ship fragments; nevertheless, a meticulous study of these timbers and the distribution of the cargo and shipboard items on the seabed resulted in a hypothetical, but carefully guided, reconstruction of the ship and the lading of its cargo. The artifacts recovered from the Uluburun shipwreck are unlike those discovered on land in quality of preservation as well as the quantity found. Items pertinent to this study include 354 copper oxhide ingots (approximately 10 tons), 152 copper bun ingots (nearly 1 ton), 110 tin ingot fragments (approximately 1 ton), 175 glass ingots (approximately 0.3 tons), 150 Canaanite jars (approximately 2 tons if filled with water), 10 large storage jars (pithoi) (approximately 3.5 tons if filled with water), approximately 51 Canaanite pilgrim flasks, 24 stone anchors (3.3 tons), nearly 1 ton of ballast stones, and the hull remains itself. Two computer programs, Rhinoceros and PHASER, were used to visually model the artifacts and ship in three-dimensions and to systematically test various hull shapes and lading arrangements in a range of hydrostatic conditions. Tests showed that a hull measuring 15 x 5 x 2 m would be capable of carrying the estimated 20 tons of cargo and shipboard items recovered from the wreck at a draft of 1 m, with sufficient freeboard to allow six passengers to stand on one side of the vessel without compromising the stability of the ship. / Institute of Nautical Archaeology

Conservation of historic buildings requires comprehensive and correct information of buildings to be analyzed in conservation decision making process in a systematic and rational approach. Geographical Information Systems (GIS) are advantageous in such cases which can be defined as computer based systems for handling geographical and spatial data. GIS have the potential to support the conservation decision making process with their storing, analyzing and monitoring capabilities. Therefore, information systems like GIS can be seen as a potential significant instrument for dealing with the conservation projects. This thesis aims to analyze the transformation process of the data collected in conservation process into practical information in order to adapt this process to a spatial information system. In this context, use of Geographical Information Systems is tested in the process of historic building conservation on spatial information system designed for Doganlar Church izmir chosen as the case study. Hence the advantages and disadvantages of local information systems in conservation decision making process of historic buildings can be criticized.

<p>The availability of digital models of real 3D objects is becoming more and more important in many different applications (e-commerce, virtual visits etc). Very often the objects to be represented cannot be modeled by means of the classical 3D modeling tools because of the geometrical complexity or color texture. In these cases, devices for the automatic acquisition of the shape and the color of the objects (3D scanners or range scanners) have to be used. </p><p>The scanner presented in this work, a Shape from silhouette scanner, is very cheap (it is based on the use of a simple digital camera and a turntable) and easy to use. While maintaining the camera on a tripod and the object on the turntable, the user acquires images with different rotation angles of the table. The fusion of all the acquired views enables the production of a digital 3D representation of the object.</p><p>Existing Shape from silhouette scanners operate in an indirect way. They subdivide the object definition space in a regular 3D grid and verify that a voxel belongs to the object by verifying that its 2D projection falls inside the silhouette of the corresponding image. Our scanner adopts a direct method: by using a new 3D representation scheme and algorithm, the Marching Intersections data structure, we can directly intersect all the 3D volumes obtained by the silhouettes extracted from the images.</p>

Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第18966号 / 工博第4008号 / 新制||工||1617 / 31917 / 京都大学大学院工学研究科都市社会工学専攻 / (主査)教授 小池 克明, 教授 石田 毅, 准教授 水戸 義忠 / 学位規則第4条第1項該当

Muscle architecture, innervation pattern and fiber type distribution of lumbar multifidus (LMT) throughout its volume was quantified. Musculotendinous (n=10) and neural components (n=3) were dissected and digitized from thirteen embalmed cadaveric specimens. The data were imported into Autodesk® Maya® 2008 to generate 3D neuromuscular models of each specimen. Architectural parameters (fiber bundle length, FBL; fiber bundle angle, FBA; tendon length) were quantified from the models using customized software. The medial branch of the posterior rami (L1-L5) was traced through LMT to determine its distribution. Using immunohistochemistry, Type I/II muscle fibers were identified in 29 muscle biopsies from one fresh frozen specimen. The total area and number of each cell type was calculated using Visiopharm® (image analysis software). Architectural and fiber type data were analyzed using ANOVA with Tukey’s post-hoc test (p ≤ 0.05). From L1-L4, LMT had three architecturally distinct regions: superficial, intermediate and deep. At L5, intermediate LMT was absent. Mean FBL decreased significantly from superficial (5.8 ± 1.6cm) to deep regions (2.9 ± 1.1cm) as did volume (superficial, 5.6 ± 2.3ml; deep, 0.7 ± 0.3ml). In contrast, mean FBA increased from superficial to deep. The medial branch of the posterior ramus (L1-L5) supplied the five bands of LMT. Each medial branch in turn divided to supply the deep, intermediate and superficial regions separately. The area occupied by Type I fibers was significantly less (p< 0.01) in the deep (56%) compared with the superficial regions (75%). Based on architecture and morphology, superficial LMT with the longest FBL and relatively small FBA is well designed for torque production and controlling the lumbar lordosis. Intermediate LMT with significantly longer FBL compared with the deep region and with its caudal to cranial line of action may help to control intersegmental stability. Furthermore, the absence of intermediate LMT at L5 and may contribute to the higher incidence of instability observed at the lumbosacral junction. Deep LMT with its short FBL, large FBA and proximity to the axis of spinal rotation may function to provide proprioceptive input to the CNS rather than a primary stabilizer of the lumbar spine.

Muscle architecture, innervation pattern and fiber type distribution of lumbar multifidus (LMT) throughout its volume was quantified. Musculotendinous (n=10) and neural components (n=3) were dissected and digitized from thirteen embalmed cadaveric specimens. The data were imported into Autodesk® Maya® 2008 to generate 3D neuromuscular models of each specimen. Architectural parameters (fiber bundle length, FBL; fiber bundle angle, FBA; tendon length) were quantified from the models using customized software. The medial branch of the posterior rami (L1-L5) was traced through LMT to determine its distribution. Using immunohistochemistry, Type I/II muscle fibers were identified in 29 muscle biopsies from one fresh frozen specimen. The total area and number of each cell type was calculated using Visiopharm® (image analysis software). Architectural and fiber type data were analyzed using ANOVA with Tukey’s post-hoc test (p ≤ 0.05). From L1-L4, LMT had three architecturally distinct regions: superficial, intermediate and deep. At L5, intermediate LMT was absent. Mean FBL decreased significantly from superficial (5.8 ± 1.6cm) to deep regions (2.9 ± 1.1cm) as did volume (superficial, 5.6 ± 2.3ml; deep, 0.7 ± 0.3ml). In contrast, mean FBA increased from superficial to deep. The medial branch of the posterior ramus (L1-L5) supplied the five bands of LMT. Each medial branch in turn divided to supply the deep, intermediate and superficial regions separately. The area occupied by Type I fibers was significantly less (p< 0.01) in the deep (56%) compared with the superficial regions (75%). Based on architecture and morphology, superficial LMT with the longest FBL and relatively small FBA is well designed for torque production and controlling the lumbar lordosis. Intermediate LMT with significantly longer FBL compared with the deep region and with its caudal to cranial line of action may help to control intersegmental stability. Furthermore, the absence of intermediate LMT at L5 and may contribute to the higher incidence of instability observed at the lumbosacral junction. Deep LMT with its short FBL, large FBA and proximity to the axis of spinal rotation may function to provide proprioceptive input to the CNS rather than a primary stabilizer of the lumbar spine.

This thesis documents the creation of a three-dimensional model of the larynx. The focus is on synthesizing the movement and appearance of laryngeal and pharyngeal sounds, with the intention of elucidating the physiological performance required of the larynx to produce these articulations. The model serves three primary purposes: the analysis of laryngeal articulation, an interactive tool for learning about linguistically relevant anatomy, and a foundation for future modeling developments such as acoustic synthesis. There are two methodological topics of discussion concerning the techniques used to generate the three-dimensional model of the larynx. The first concerns the morphological aspect of the laryngeal architecture. Laryngeal structures were segmented from a series of histological images using a process known as vertex tracing to generate wire-frame computer representations, or meshes, of the laryngeal structures featured in the model. The meshes were then carefully placed within the three-dimensional space used to generate a scene of the larynx that could be rendered and presented to the user of the program. Frame hierarchies, an organization scheme for vertices, were imposed on flexible tissue meshes to attach and manipulate various moving structures found in the larynx. Finally, basic mechanical features of laryngeal movement derived from research into the biomechanics of laryngeal physiology were implemented. The second methodological topic pertains to the analysis of laryngoscopic videos to obtain data that describes the movement patterns used to generate the laryngeal and pharyngeal articulations of interest. There are three image analysis techniques applied to the laryngoscopy. The first uses normal speed laryngoscopy to assess end-state articulations, by comparing various geometrical aspects of laryngeal landmarks as they differ between the maximally open setting (used for deep inspiration), and the articulatory target setting. With this technique, various phonation types and segmental articulations are assessed using videos of a phonetician carefully performing the articulations. Some comparison of these articulations to their analogues in the speech of native speakers from various languages is made for the sake of illustration and verification. The second image analysis technique used is applied to high-speed laryngoscopic video of aryepiglottic trilling, which is an important function of the laryngeal constrictor mechanism. The left and right aryepiglottic apertures during trilling are analyzed using binary-conversion and area measurement. The third technique takes the same high-speed laryngoscopic video of aryepiglottic trilling and extracts motion vectors between frame pairs to characterize the directionality and magnitude of motion occurring for each of the folds. Using the image analysis data, model movements are constrained and synchronized to recreate the articulations observed in the laryngoscopic videos. One of the major innovations of this model is a biomechanical simulation of aryepiglottic fold trilling, based primarily upon the data collected from the high-speed laryngoscopic videos. Overall the model represents one of the first attempts to visually recreate laryngeal articulatory function in a way that is dynamic and interactive. Future work will involve dynamic acoustic synthesis for laryngeal states represented by the model.