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.

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. / Project done at USC Institute for Creative Technologies, LA, USA. Presented at SIGGRAPH09.

In modern research and industrial applications, the importance of coatings can hardly be underestimated. Coatings are used extensively in optics, biomedical instruments, cutting tools, and solar panels to name a few. The primary purpose of any coating is to alter surface properties of the base material thus adding new functionality or improving the performance of the original product. A multitude of coating techniques has evolved over the years with spray coating being one of the more widely used. Some applications require deposition of materials that are either in the form of a solution or suspension. Therefore, before or during the deposition process small droplets of the said liquid are formed and transferred onto the substrate. Since differently sized droplets have different surface impact dynamics, droplet velocity at the impact plays an important role in the way it will adhere to the surface. Most spray coating techniques do not take into account the process of droplet-surface interaction which may result in overspray, poor coating thickness control, and material waste. The research presented in this dissertation outlines the supporting principles, design, fabrication and testing of an innovative spray coating system that provides the ability to fine tune coating parameters, including droplet impact velocities, to provide close to optimum deposition conditions. The core of the design consist of a dual velocity nozzle unit that ensures acceptable range of droplet velocities at the surface, while keeping droplets from accelerating excessively inside the system. Early experiments showed the system’s potential to produce nanoparticle coatings with particles uniformly distributed across the substrate. In addition, pigment coating for improved 3D scanning was also performed, thereby improving the surface definition and accuracy of the scanning results. Scalability of the system also led to experiments in applying this technology to microprinting. Preliminary microprinting results illustrated the system’s flexibility and opened new research avenues in micro-coating, microprinting, and, possibly rapid prototyping. Furthermore, thanks to the highly adaptable nature of the proposed design, seamless incorporation of a torch-like device into the nozzle unit was also possible. That provided the opportunity to perform in situ thermal processing or sintering of deposited material as well as production of a nanoparticle coating in a one-step process by thermally decomposing precursor solution. Technology developed during the research work presented in this dissertation demonstrated its ability to be adapted in a number of applications that can benefit both industry and engineering research alike. Large area coatings, nanoparticle production, micro-coating, and coatings for improved 3D scanning are just a few areas where the presented technique can already, or may, if developed further, outperform existing and widely accepted methods. Fine tuning of the system to a particular application, and tapping into its potential in other fields will be explored in future research. / Graduate

This diploma thesis deals with matte coatings for optical 3D scanning. The aim of this thesis is to find a method of spraying the mixture of TiO2 and ethanol that would provide layer thickness beyond the measurable range of the 3D scanner. A spray gun allowing deposition of atomized mixture was design. The coatings created by this gun and by airbrush gun, which is commonly used for this purpose, were compared. The matting effect, thickness and the influence of used TiO2 particles were investigated in the coatings. The paper shows method of applying coatings that ensure sufficient matting of the surface for scanning purposes, and simultaneously have thicknesses that should not affect scanning results.

This thesis focuses on comparison of the commonly used method of tactile measurement with 3D scanning methods for their introduction into engineering production. The first part summarizes the current state with the description of measurement technologies with emphasis on 3D technologies and their versatile use. The second part presents a practical comparison of three types of measuring devices on a selected component of a bicycle. After numerical and graphical evaluation of the measurement results, these values are further statistically processed and the measurement uncertainties are calculated. The final part of the work evaluates the whole process and presents practical suggestions, options and recommendations.

An experimental methodology for wear assessment of extracted polyethylene hip implants was designed in this diploma thesis. Methodology uses optical 3D scanner and optical profilometer for analysis of wear. Designed methodology for wear analysis was validated by gravimetric method. The results of validation were in good agreement with the increase of wear rate. Validation results show that the methodology is not suited for wear assessment of metal and ceramic implants which have small wear rates. On the other hand the methodology is more than useful for wear assessment of polyethylene implants. Designed methodology for wear assessment was applied on the set of thirteen extracted polyethylene hip implants. Results of the wear analysis were wear volumes and linear wear noted in the wear maps. Roughness of the surface was measured on explanted cups and results were noted in the roughness map. On articulating surface of the cups different areas were observed for measured roughness. Those areas were described as area with machining marks from manufacturing process, polished area from combination of abrasive and adhesive wear, polished area from micro-contact fatigue and area including plastic deformation.

The aim of this thesis was to produce a prototype casting of aluminum alloy with usage of reverse engineering technology. In a production process surface quality and dimensional accuracy was optimized. 3D scanning, FDM technology, ABSplus surface finishing possibilities and investment casting technology is introduced in theoretical part of this thesis. Practical part of the thesis includes description of original parts, their 3D scanning, usage of RE and RP, production of new castings and evaluation of their dimensional accuracy and surface roughness.

Mit Techniken der Computergraphik können bewegte drei-dimensionale Oberflächen mit höchsten visuellen Details generiert und dargestellt werden. Mittlerweile sind die Ergebnisse so gut, dass beispielsweise virtuelle menschliche Gesichter in Filmen und Videospielen kaum noch von realen zu unterscheiden sind. Auch in der Ergonomie werden immer genauere Mensch-Modelle und Simulationen verwendet, beispielsweise zur Validierung und Verbesserung von Textilien.

Footwear and tire impressions are critical evidence commonly found at a crime scene. However, they are often undervalued because they are hard to be captured and documented. Traditional 2D evidence quality photographs do not adequately provide metric depth information, and physical casts destroy the evidence afterward. Therefore, the forensic science community raised the need for improved evidence recognition, collection, and visualization analytical instrumentation for field and lab use. While the 3D optical techniques for imaging static objects have been extensively studied, there is still a major gap between current knowledge and collecting high-quality footwear and tire impressions evidence. Among optical means for 3D imaging, digital fringe projection (DFP) techniques reconstruct 3D shape from phase information, achieving camera-pixel spatial resolution. This paper presents a high-resolution 3D imaging technology using DFP techniques dedicated to footwear and tire impression capture. We developed fully automated software algorithms and a graphical user interface (GUI) that allow anyone without training to operate for high-quality 3D data capture. We performed accuracy evaluations and comparisons comparing with the commercial high-end 3D scanner and carried out qualitative tests for various impressions comparing with the current practices. Overall, our technology achieves similar levels of accuracy and resolution with a high-end commercially available 3D scanner, while having the merits of being 1) more affordable; 2) much easier to operate, and 3) more robust. Compared with the current practice of casting, our technology demonstrates its superiority because it 1) is non-destructive; 2) collects more evidence detail than casts, especially when an impression is fragile; 3) requires less time and money to collect each piece of evidence, and 4) results in a digital file that can easily be shared with other examiners.<br>

Welded structures susceptible to weld deformations require sequent processing to allow for mounting of precision components. This thesis includes a case study of the rear axle mount on a Volvo L220 wheel loader. A product development process was deployed in order to explore and evaluate alternative mounting methods such that manufacturing cost due to sequent processing could be decreased. Analysis of the frame variations showed any new concepts has to accommodate variations of up to $\delta z=-1.24\pm3.5$ mm. The product development process found two potential concept philosophies; transferring concepts which improves upon the current concept by transferring the processing away from the frame onto smaller components that are cheaper to process, and absorbing concepts that avoids sequent processing by absorbing the frame variations altogether. The transferring concept "Custom Plate" was selected for further development. The concept is based on the principals of reverse engineering by manufacturing a custom plate from a 3D surface map of the deformed mounting surface, placed between the frame and rear axle bridge, matching the surface geometry of both entities. The concept showed no apparent critical strength issues when simulated in CATIA V5. However, the economical gain of the concept is slim and depends heavily what spaces can be allocated for additional processing machinery. Suggestions for further development of the concept are given along with a discussion of improvements outside of the system boundary of the project, such as simulation of welds and welding sequence, and collection, storing, analysis, and visualisation of data.