The purpose of this in vitro study was to investigate and to compare the precision of two different impression techniques for oral prosthetic construction, namely the analogue modified double tray method, and the digital three-dimensional scanning with Trios 3D shape intraoral scanner. The analog method used was a modified double tray method where the tray had been removed to diminish vertical discrepancies in occlusion. All testing was based on a master model with a prepared acrylic tooth from which a total of 20 milled crowns in polymethylmethacrylate was produced, 10 from each impression method.  The fit of the crowns was evaluated according to a clinical protocol and the cement gap was measured with a measuring microscope. Each crown was fitted on to the master model with Flexitime light body, mimicking a cementing procedure. The resulting “cement layer” was after setting of the silicone impression material removed and divided into 4 equal pieces which subsequently were measured in a measuring microscope. Statistical analysis of the resulting measurements showed no significant differences in precision when comparing the impression methods. Because of a manufacturing error in the milling procedure, all of the milled plastic crowns showed suboptimal fit on the master model. However, it was concluded that no statistical - nor clinical difference between the two methods could be established. Most likely, both methods can be used for fabrication of single unit prosthetic reconstructions with adequate precision for effective treatment.

Aim: The aim of this study was to validate the 3D Sense scanner to evaluate its accuracy and eventual use in odontology. Method: In this study, a model of a head was created with anthropometric landmarks. The 3D Sense scanner was used for examinations of distances and angle accuracy. The results of the 3D Sense scan were then compared to a reference master model to get the standard deviation and reliability of the 3D Sense scanner. Results: The 3D Sense scanner showed a varying accuracy depending on the positioning and distance between the measuring points on the model. The best perception of the 3D Sense proved to be when the scanner was held still in a static position. The more movement of the scanner, the less accurate result. Conclusion: The present 3D scan analysis of 3D Sense proved overall a good reliability and reproducibility. To implement the 3D Sense scanner in odontological treatment, further studies are needed with refined technique in order to get all of the measurement accurate.

Plumage is a stereoscopic 3D experience showcasing the culmination of a personal exploration and observation of birds: a digitally modeled and rendered, fantastical bird referred to simply as a Phoenix. In many cultures birds are tied to ideas of freedom, power, and the otherworldly. Preconceived notions of a phoenix exist across many cultures as well, but for this project I wanted to create my own interpretation. While working, I drew upon my admiration of birds for their qualities of strength, beauty, and curiosity to infuse into the project. Inspired by the dynamic and detailed works of naturalists like John James Audubon, I took the opportunity to make my own observations and records of birds. I began exploring different processes of digitizing three-dimensional forms by scanning bird skins. However, due to the nature of fibrous and reflective materials (of which birds are often both) I ran into challenges that made accurate and detailed representation difficult if not impossible. From there I made the decision to pursue a more imaginative artistic approach to the project. More than just a homage to feathers and birds, this project represents the continued value of artists in the field of preservation and their ability to push visuals further with their own observations where automation and digitization fall short. Using life references I created my own textures and forms with details meant to emulate my favorite aspects of the birds that inspired me throughout my journey. Larger-than-life, projected stereoscopic 3D allows the audience to see details clearly and enhances the dynamic quality of the piece; both very important elements that needed to shine through in the final artwork. Plumage is made possible through the use of the Cyclorama, a series of convex screens that surround an audience and allow them to appreciate scenes projected in stereoscopic 3D. / Master of Fine Arts / <i>Plumage</i> is a projected 3D experience that uses state-of-the-art projectors, 3D glasses, and a large, cylindrical screen--known as the Cyclorama. My research began with a focus on 3D scanning dead bird specimens from a museum collection as a means to archive them and make them viewable by anyone with access to a computer. Unfortunately, the scanner I used could not effectively capture the intricate shapes and colors of feathers, and the resulting scans were not sufficiently detailed for learning or archival purposes. In the end, I used the observational data I had collected from the bird specimens to digitally sculpt my own ficticious species of bird. I closely studied the feathers and wing structures of the birds available to me to recreate a detailed, digital 3D representation where scanning had failed. Using software, I created still images of the finished digital bird sculpture. To create the 3D effect when projected onto a screen, I created pairs of images for the left and right eyes. The projectors and 3D glasses, coordinated with a powerful computer, allowed the audience to experience convincing 3D effects such as the Phoenix jumping out or sweeping a wing at its audience.

The thesis describes state of the art volumetric measurement techniques and applies a 3D measurement technique, 3D Scanning Particle Tracking Velocimetry, to the transitional backward facing step flow. The measurement technique allows the spatial and temporal analysis of coherent structures apparent at the backward facing step. The thesis focusses on the extraction and interaction of coherent flow structures like shear layers or vortical structures.

Termovizní zobrazování i 3D skenování jsou v současné době rychle se rozvíjející technologie. Obě technologie mají mnoho výhod, které by mohly být užitečné v medicíně. Jejich datová fúze přináší ještě více nových diagnostických informací, než kdyby byly použity samostatně. Cílem této práce je vývoj multispektrálního 3D skenovacího systému založeného na novém způsobu snímání pomocí robotického manipulátoru vybaveného laserovým snímačem, teplotní kamerou a barevnou kamerou. Navržené řešení přináší jak flexibilitu, tak přesnost. Tento systém skenování je dále využit v klinických aplikacích, aby byly ověřeny jeho schopnosti a ukázány přínosy nad rámec současného stavu techniky.

A modelagem de geometrias da natureza pode ser um processo complexo devido ás características orgânicas dos elementos. Propõe-se com essa dissertação identificar geometrias espaciais que sigam o padrão de crescimento espiral observado na natureza, utilizando as Tecnologias 3D como ferramentas para o processo de projeto. Para a execução do trabalho foram investigadas os Métodos de Biônica, Crescimento Espiral e a Sequência de Fibonacci, Engenharia Reversa e Design Paramétrico. O processo de representação dos elementos foi realizado em conformidade com a Metodologia para o Desenvolvimento de Produtos Baseados no Estudo da Biônica com o acréscimo das tecnologias de digitalização tridimensional e de processamento de nuvem de pontos, complementado pela parametrização de superfícies à base de curvas. Foram utilizados três processos para modelagem de curvas paramétricas representadas (i) pelo desenho de linhas sobre a malha digitalizada em 3D, (ii) por programação visual no software Grasshopper e (iii) por programação com scripts Python. Foi avaliada como melhor alternativa para o Design Paramétrico a utilização da programação visual otimizada com a programação por scripts, a qual apresentou melhor aproximação entre as curvas analisadas. Estudos de casos realizados com elementos da natureza (abacaxi e pinha) demonstraram a viabilização do método. Desta maneira a sistematização do conhecimento permitirá a proposição de um modelo paramétrico baseado na Biônica para fase inicial de inspiração e concepção de alternativas do projeto de produto. / Modeling the geometries of nature can be a complex process due to the organic characteristics of the elements. It is proposed with this dissertation to identify spatial geometries that follow the pattern of spiral growth observed in nature, using 3D Technologies as tools for the design process. For the execution of the work were investigated the Bionics, Spiral Growth and Fibonacci Sequence, Reverse Engineering and Parametric Design. The process of representation of the elements was carried out in accordance with the Methodology for the Development of Products Based on the Study of the Bionics with the addition of the technologies of three-dimensional digitization and processing of cloud of points, complemented by the parameterization of surfaces based on curves. Three methods were used for modeling parametric curves represented by (i) the drawing of lines on the 3D scanned mesh, (ii) by visual programming in the Grasshopper software and (iii) by programming with Python scripts. It was evaluated as the best alternative for Parametric Design the use of optimized visual programming with programming by scripts, which presented better approximation between the analyzed curves. Case studies carried out with nature elements (pineapple and pine cone) demonstrated the viability of the method. In this way the systematization of the knowledge will allow the proposition of a parametric model based on the Bionics for the initial phase of inspiration and design of alternatives of the product design.

<p>This report summarizes the work done to develop a 3D teleconferencing system, which enables remote participants anywhere in the world to be scanned in 3D, transmitted and displayed on a constructed 3D display with correct vertical and horizontal parallax, correct eye contact and eye gaze. The main focus of this report is the development of this system and especially how to in an efficient and general manner render to the novel 3D display. The 3D display is built out of modified commodity hardware and show a 3D scene for observers in up to 360 degrees around it and all heights. The result is a fully working 3D Teleconferencing system, resembling communication envisioned in movies such as holograms from Star Wars. The system transmits over the internet, at similar bandwidth requirements as concurrent 2D videoconferencing systems.</p> / Project done at USC Institute for Creative Technologies, LA, USA. Presented at SIGGRAPH09.

The application of 3D laser scanning to the analysis of human skeletal remains provides the opportunity for new methodological approaches, including for the assessment of age at death. The focus of this new perspective revolves around the question of whether morphological development of skeletal features can be captured with quantitative measurements taken from 3D scanned representations of physical specimens, with the aims of adding an increased level of accuracy and precision over currently employed age estimations methods that focus on visual, and often subjective, assessments based comparisons with plaster casts and written descriptions. The current research was conducted to determine if specific morphological features of the pubic symphysis could be isolated and quantified on 3D models, and whether these measurements captured the general age related trends of symphyseal development. Using CAD software, each symphyseal face was divided into half and quadrant specific sections in an attempt to better capture the development of symphyseal morphology. A sample of left male pubic symphyses (n = 40) scanned from a well-documented collection of known-age individuals (Coimbra Identified Skeletal Collection) was selected for this study. Seven symphyseal features were identified from the Suchey-Brooks method unisex age phase descriptions. Eight measurements were generated to quantify these features. The data for each feature was subjected to linear regression analyses to test for statistical correspondence to known chronological age at death. Rim completeness, billowing height and area, and depth of symphyseal face depression demonstrated the strongest relationships with chronological age, while curvature of the ventral rampart and the angle of the dorsal aspect, showed significant but weak relationships with known age. Degree of dorsal lipping and dorsal rampart curvature showed no relationship with age. The results of the study suggest that quantitative assessments of morphological changes at the pubic symphysis are possible and therefore can potentially add further insights into age at death estimations based on the pubic symphysis, as measurements taken within CAD software are far more precise than traditional measuring implements. This study illustrates the potential for 3D imaging to improve the methods of osteological analyses applied particularly in the fields of bioarchaeology and forensic anthropology. / Graduate

This study aims to comprehend the bistable and multi-stable behaviour of flexible straws with the intention of utilising it for future engineering applications. This behaviour is achieved by the multiple inversions of conical frustum shells within the corrugation of a flexible straw. This study examined the effects of various material models, geometry variables and loading methods on the inversion of close-top and open-top conical frustum shells via experiments and FEM simulations. This thesis consists of three main parts, and the second and the third parts are complementary to each other: First, we investigated the effects of applying a uniform vertical load to the upper rim of open-top frustum shells via FEM simulations. A reference model was simulated based on the measurements of an ordinary polypropylene flexible straw specimen, using two material models - linear elastic and elastically perfectly plastic. The effects of the interactions between frusta of the corrugated segment of a flexible straw were also studied by evaluating the difference in responses between an individual frustum and conjugated models of two or three frusta. It was found that by constraining the rotation of its bottom rim, an individual frustum can fairly reproduce the complex bistable behaviour of the shorter frustum within the corrugated part of a flexible straw. Furthermore, detailed parametric studies that focused on the effects of various geometric parameters were conducted and generalised formulas that predicted the critical force were derived. A comparison between the simulated results and the analytical model in predicting progressive inversion was made to distinguish the geometric boundaries that separate the one-off snap-through to the progressive inversion of frustum shells. Next, the behaviour of close-top frustum shells in response to vertical point loading at various locations on the top surface was evaluated. A hyperelastic material was used to fabricate the physical specimens. During the experiments, the corresponding deformed shapes were recorded by 3D scanning in addition to measurements of the displacement and reaction force. We observed a close resemblance between the experimental and FEM simulated results, which validated the FEM models. Two local peaks were observed before the structure was fully inverted into its secondary stable state and the overall critical force of the structure was defined by the higher one of the two. The relationship between their magnitudes and the loading locations was analysed and an optimal loading location which gave the minimum critical force was proposed and verified by additional simulations. Furthermore, generalised formulas in predicting critical force were also acquired based on parametric studies. The optimal loading location was found to be constant in spite of variations in height and thickness. The third part of this thesis discussed the effects of lateral point loading on both close-top and open-top frustum shells at various locations on the side surface and supplemented the second part. It is found that the removal of the top surface could cause the critical force to decrease if a point load was applied laterally. Moreover, we were able to fully invert the structure with a lower critical force through lateral loading in comparison to vertical loading.

A modelagem de geometrias da natureza pode ser um processo complexo devido ás características orgânicas dos elementos. Propõe-se com essa dissertação identificar geometrias espaciais que sigam o padrão de crescimento espiral observado na natureza, utilizando as Tecnologias 3D como ferramentas para o processo de projeto. Para a execução do trabalho foram investigadas os Métodos de Biônica, Crescimento Espiral e a Sequência de Fibonacci, Engenharia Reversa e Design Paramétrico. O processo de representação dos elementos foi realizado em conformidade com a Metodologia para o Desenvolvimento de Produtos Baseados no Estudo da Biônica com o acréscimo das tecnologias de digitalização tridimensional e de processamento de nuvem de pontos, complementado pela parametrização de superfícies à base de curvas. Foram utilizados três processos para modelagem de curvas paramétricas representadas (i) pelo desenho de linhas sobre a malha digitalizada em 3D, (ii) por programação visual no software Grasshopper e (iii) por programação com scripts Python. Foi avaliada como melhor alternativa para o Design Paramétrico a utilização da programação visual otimizada com a programação por scripts, a qual apresentou melhor aproximação entre as curvas analisadas. Estudos de casos realizados com elementos da natureza (abacaxi e pinha) demonstraram a viabilização do método. Desta maneira a sistematização do conhecimento permitirá a proposição de um modelo paramétrico baseado na Biônica para fase inicial de inspiração e concepção de alternativas do projeto de produto. / Modeling the geometries of nature can be a complex process due to the organic characteristics of the elements. It is proposed with this dissertation to identify spatial geometries that follow the pattern of spiral growth observed in nature, using 3D Technologies as tools for the design process. For the execution of the work were investigated the Bionics, Spiral Growth and Fibonacci Sequence, Reverse Engineering and Parametric Design. The process of representation of the elements was carried out in accordance with the Methodology for the Development of Products Based on the Study of the Bionics with the addition of the technologies of three-dimensional digitization and processing of cloud of points, complemented by the parameterization of surfaces based on curves. Three methods were used for modeling parametric curves represented by (i) the drawing of lines on the 3D scanned mesh, (ii) by visual programming in the Grasshopper software and (iii) by programming with Python scripts. It was evaluated as the best alternative for Parametric Design the use of optimized visual programming with programming by scripts, which presented better approximation between the analyzed curves. Case studies carried out with nature elements (pineapple and pine cone) demonstrated the viability of the method. In this way the systematization of the knowledge will allow the proposition of a parametric model based on the Bionics for the initial phase of inspiration and design of alternatives of the product design.