272 research outputs found

    SlicerAstro: a 3-D interactive visual analytics tool for HI data

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    SKA precursors are capable of detecting hundreds of galaxies in HI in a single 12 hours pointing. In deeper surveys one will probe more easily faint HI structures, typically located in the vicinity of galaxies, such as tails, filaments, and extraplanar gas. The importance of interactive visualization has proven to be fundamental for the exploration of such data as it helps users to receive immediate feedback when manipulating the data. We have developed SlicerAstro, a 3-D interactive viewer with new analysis capabilities, based on traditional 2-D input/output hardware. These capabilities enhance the data inspection, allowing faster analysis of complex sources than with traditional tools. SlicerAstro is an open-source extension of 3DSlicer, a multi-platform open source software package for visualization and medical image processing. We demonstrate the capabilities of the current stable binary release of SlicerAstro, which offers the following features: i) handling of FITS files and astronomical coordinate systems; ii) coupled 2-D/3-D visualization; iii) interactive filtering; iv) interactive 3-D masking; v) and interactive 3-D modeling. In addition, SlicerAstro has been designed with a strong, stable and modular C++ core, and its classes are also accessible via Python scripting, allowing great flexibility for user-customized visualization and analysis tasks.Comment: 18 pages, 11 figures, Accepted by Astronomy and Computing. SlicerAstro link: https://github.com/Punzo/SlicerAstro/wiki#get-slicerastr

    A 3D Pipeline for 2D Pixel Art Animation

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    Aquest document presenta un informe exhaustiu sobre un projecte destinat a desenvolupar un procés automatitzat per a la creació d'animacions 2D a partir de models 3D utilitzant Blender. L'objectiu principal del projecte és millorar les tècniques existents i reduir la necessitat que els artistes realitzin tasques repetitives en el procés de producció d'animació. El projecte implica el disseny i desenvolupament d'un complement per a Blender, programat en Python, que es va desenvolupar per ser eficient i reduir les tasques intensives en temps que solen caracteritzar algunes etapes en el procés d'animació. El complement suporta tres estils específics d'animació: l'art de píxel, "cel shader", i "cel shader" amb contorns, i es pot expandir per suportar una àmplia gamma d'estils. El complement també és de codi obert, permetent una major col·laboració i potencials contribucions per part de la comunitat. Malgrat els problemes trobats, el projecte ha estat exitós en aconseguir els seus objectius, i els resultats mostren que el complement pot aconseguir resultats similars als adquirits amb eines similars i animació tradicional. El treball futur inclou mantenir el complement actualitzat amb les últimes versions de Blender, publicar-lo a GitHub i mercats de complements de Blender, així com afegir nous estils d'art.This document presents a comprehensive report on a project aimed at developing an automated process for creating 2D animations from 3D models using Blender. The project's main goal is to improve upon existing techniques and reduce the need for artists to do clerical tasks in the animation production process. The project involves the design and development of a plugin for Blender, coded in Python, which was developed to be efficient and reduce time-intensive tasks that usually characterise some stages in the animation process. The plugin supports three specific styles of animation: pixel art, cel shading, and cel shading with outlines, and can be expanded to support a wider range of styles. The plugin is also open-source, allowing for greater collaboration and potential contributions from the community. Despite the challenges faced, the project was successful in achieving its goals, and the results show that the plugin could achieve results similar to those acquired with similar tools and traditional animation. The future work includes keeping the plugin up-to-date with the latest versions of Blender, publishing it on GitHub and Blender plugin markets, as well as adding new art styles

    A review of existing evaluation methods for point clouds quality

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    This paper analyzes the existing evaluation methods for the point cloud quality and a new discussion regarding their applicability to aerial photographs is opened. Some of these methods are chosen based on practical issues and applied to a pair of reconstructions. The principal conclusion is that objective methods are the most interesting in photogrammetry applications, particularly the comparison between two point clouds.CONACYT – Consejo Nacional de Ciencia y TecnologíaPROCIENCI

    Innovative Approaches to 3D GIS Modeling for Volumetric and Geoprocessing Applications in Subsurface Infrastructures in a Virtual Immersive Environment

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    As subsurface features remain largely ‘out of sight, out of mind’, this has led to challenges when dealing with underground space and infrastructures and especially so for those working in GIS. Since subsurface infrastructure plays a major role in supporting the needs of modern society, groups such as city planners and utility companies and decision makers are looking for an ‘holistic’ approach where the sustainable use of underground space is as important as above ground space. For such planning and management, it is crucial to examine subsurface data in a form that is amenable to 3D mapping and that can be used for increasingly sophisticated 3D modeling. The subsurface referred to in this study focuses particularly on examples of both shallow and deep underground infrastructures. In the case of shallow underground infrastructures mostly two-dimensional maps are used in the management and planning of these features. Depth is a very critical component of underground infrastructures that is difficult to represent in a 2D map and for this reason these are best studied in three-dimensional space. In this research, the capability of 3D GIS technology and immersive geography are explored for the storage, management, analysis, and visualization of shallow and deep subsurface features

    Interfaces for human-centered production and use of computer graphics assets

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    L'abstract è presente nell'allegato / the abstract is in the attachmen

    Spacesuit Hard Upper Torso Assembly: Development Of Fit Metrics And Customized Design Frameworks

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    The Hard Upper Torso (HUT) of the spacesuit pressure garment is a central component of a spacesuit, enclosing the upper body and connecting with the shoulder joints, bearings, helmet, hatch, and waist-brief-hip components. The shape and positioning of the HUT and its connected components are critical for ensuring comfort, range of motion, field of view, and minimizing astronaut injury risk.This dissertation aims to build upon previous work on spacesuit sizing and develop new spacesuit fit metrics. Motion-tracking technology has been utilized to define the reach envelope and range of motion for test subjects wearing a HUT. Subjective surveys have also been conducted to evaluate suit mobility, feature alignment, indexing, and discomfort. These tools can be adapted to investigate the effects of HUT sizing, leading to the proposal of new metrics ideal for the fit and mobility of HUT based on these technologies. Additive manufacturing can be employed to create custom spacesuit hardware with minimal additional manufacturing steps. This technique enables efficient testing and benchmarking of a wide variety of HUT prototypes. With the development of fit and performance metrics, it becomes logical to utilize these metrics to design optimally sized HUT geometry. The above goals were pursued through the following activities: 1. Define two separate HUT design frameworks: The first framework will result in an optimally distributed discreet HUT sizing system, while the second will establish a framework for the rapid prediction and design of customized HUTs. 2. Investigate the subjective effect of HUT customization on HUT fitment using a subjective fit survey, demonstrating the benefits of HUT customization. 3. Explore the effect of HUT customization using human in-the-loop testing, including range of motion and reach envelope analyses, highlighting the benefits of HUT customization on suited mobility. 4. Confirm the preliminary feasibility of 3D printed HUTs through stress analysis of virtual HUT prototypes using a range of pressures, shell thicknesses, and candidate materials

    Reducing the environmental impact of hydraulic fracturing pumps

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    This thesis was previously held under moratorium from 01/12/16 to 01/12/21The current approach to hydraulic fracturing requires large amounts of industrial hard-ware to be transported, installed and operated in temporary locations. Typically 70% of the mass of this equipment is comprised of the fleet of truck-mounted pumps required to provide the high pressures and flows necessary for well stimulation. The established design of these pumps were developed for the shale gas extraction industry in North America, where the environmental, geological, regulatory and social constraints are very different from Europe. Consequently the engineering choices made in the current pump designs did not focus on minimising the physical and environmental footprint of the operation. These aspects are of paramount importance for the emerging hydraulic fracturing industry in Europe, so it is timely to address these factors when considering the design of future high-pressure pumps for European shale resources. This thesis develops and applies a methodology for environmental optimisation of the key mechanical design parameters for the high-pressure pumps that are central to hydraulic fracturing operations. Before describing the optimisation methodology the thesis provides an overview of the industrial plant required to carry out a hydraulic fracturing operation, and an estimate of the functional requirements (i.e. pressure and flow) of the equipment. The computational model, central to the optimisation process, is validated by using field data from a hydraulic fracturing site in North America and an experimental test rig. The optimisation analysis concludes that reducing the plunger diameter and running the pump at higher angular velocity, with lower forces, can increase pump efficiency by up to 4.6%. Furthermore the modification of the pump’s parameters would result in several environmental benefits beyond the obvious economic gains of lower fuel con-sumption. Previous studies have shown that over 90% of the emissions of CO2 and other pollutants that occur during a hydraulic fracturing operation are associated with the pumps and their prime movers. Consequently, any increase in pumping efficiency will also reduce the greenhouse gas emissions and improve local air quality (CO2, NOx and other pollutants). Additionaly, the reduction in plunger diameter will reduce the amplitude of fatigue stresses and so increase the life of the units and allow their overall mass to be reduced. More reliable pumps could decrease the number of standby (i.e. backup) units necessary, and so reduce procurement costs and site traffic, including the overall site footprint. The concluding system optimisation study suggests that the highest level of direct on-site emission is due to the inefficient and asynchronous operation of multiple frac-truck assemblies. Reducing the number of frac-truck assemblies subsequently affects pump traffic lowering the nuisance effects to the local community such as noise, road damage and road traffic risk.The current approach to hydraulic fracturing requires large amounts of industrial hard-ware to be transported, installed and operated in temporary locations. Typically 70% of the mass of this equipment is comprised of the fleet of truck-mounted pumps required to provide the high pressures and flows necessary for well stimulation. The established design of these pumps were developed for the shale gas extraction industry in North America, where the environmental, geological, regulatory and social constraints are very different from Europe. Consequently the engineering choices made in the current pump designs did not focus on minimising the physical and environmental footprint of the operation. These aspects are of paramount importance for the emerging hydraulic fracturing industry in Europe, so it is timely to address these factors when considering the design of future high-pressure pumps for European shale resources. This thesis develops and applies a methodology for environmental optimisation of the key mechanical design parameters for the high-pressure pumps that are central to hydraulic fracturing operations. Before describing the optimisation methodology the thesis provides an overview of the industrial plant required to carry out a hydraulic fracturing operation, and an estimate of the functional requirements (i.e. pressure and flow) of the equipment. The computational model, central to the optimisation process, is validated by using field data from a hydraulic fracturing site in North America and an experimental test rig. The optimisation analysis concludes that reducing the plunger diameter and running the pump at higher angular velocity, with lower forces, can increase pump efficiency by up to 4.6%. Furthermore the modification of the pump’s parameters would result in several environmental benefits beyond the obvious economic gains of lower fuel con-sumption. Previous studies have shown that over 90% of the emissions of CO2 and other pollutants that occur during a hydraulic fracturing operation are associated with the pumps and their prime movers. Consequently, any increase in pumping efficiency will also reduce the greenhouse gas emissions and improve local air quality (CO2, NOx and other pollutants). Additionaly, the reduction in plunger diameter will reduce the amplitude of fatigue stresses and so increase the life of the units and allow their overall mass to be reduced. More reliable pumps could decrease the number of standby (i.e. backup) units necessary, and so reduce procurement costs and site traffic, including the overall site footprint. The concluding system optimisation study suggests that the highest level of direct on-site emission is due to the inefficient and asynchronous operation of multiple frac-truck assemblies. Reducing the number of frac-truck assemblies subsequently affects pump traffic lowering the nuisance effects to the local community such as noise, road damage and road traffic risk

    3D photogrammetric data modeling and optimization for multipurpose analysis and representation of Cultural Heritage assets

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    This research deals with the issues concerning the processing, managing, representation for further dissemination of the big amount of 3D data today achievable and storable with the modern geomatic techniques of 3D metric survey. In particular, this thesis is focused on the optimization process applied to 3D photogrammetric data of Cultural Heritage assets. Modern Geomatic techniques enable the acquisition and storage of a big amount of data, with high metric and radiometric accuracy and precision, also in the very close range field, and to process very detailed 3D textured models. Nowadays, the photogrammetric pipeline has well-established potentialities and it is considered one of the principal technique to produce, at low cost, detailed 3D textured models. The potentialities offered by high resolution and textured 3D models is today well-known and such representations are a powerful tool for many multidisciplinary purposes, at different scales and resolutions, from documentation, conservation and restoration to visualization and education. For example, their sub-millimetric precision makes them suitable for scientific studies applied to the geometry and materials (i.e. for structural and static tests, for planning restoration activities or for historical sources); their high fidelity to the real object and their navigability makes them optimal for web-based visualization and dissemination applications. Thanks to the improvement made in new visualization standard, they can be easily used as visualization interface linking different kinds of information in a highly intuitive way. Furthermore, many museums look today for more interactive exhibitions that may increase the visitors’ emotions and many recent applications make use of 3D contents (i.e. in virtual or augmented reality applications and through virtual museums). What all of these applications have to deal with concerns the issue deriving from the difficult of managing the big amount of data that have to be represented and navigated. Indeed, reality based models have very heavy file sizes (also tens of GB) that makes them difficult to be handled by common and portable devices, published on the internet or managed in real time applications. Even though recent advances produce more and more sophisticated and capable hardware and internet standards, empowering the ability to easily handle, visualize and share such contents, other researches aim at define a common pipeline for the generation and optimization of 3D models with a reduced number of polygons, however able to satisfy detailed radiometric and geometric requests. iii This thesis is inserted in this scenario and focuses on the 3D modeling process of photogrammetric data aimed at their easy sharing and visualization. In particular, this research tested a 3D models optimization, a process which aims at the generation of Low Polygons models, with very low byte file size, processed starting from the data of High Poly ones, that nevertheless offer a level of detail comparable to the original models. To do this, several tools borrowed from the game industry and game engine have been used. For this test, three case studies have been chosen, a modern sculpture of a contemporary Italian artist, a roman marble statue, preserved in the Civic Archaeological Museum of Torino, and the frieze of the Augustus arch preserved in the city of Susa (Piedmont- Italy). All the test cases have been surveyed by means of a close range photogrammetric acquisition and three high detailed 3D models have been generated by means of a Structure from Motion and image matching pipeline. On the final High Poly models generated, different optimization and decimation tools have been tested with the final aim to evaluate the quality of the information that can be extracted by the final optimized models, in comparison to those of the original High Polygon one. This study showed how tools borrowed from the Computer Graphic offer great potentialities also in the Cultural Heritage field. This application, in fact, may meet the needs of multipurpose and multiscale studies, using different levels of optimization, and this procedure could be applied to different kind of objects, with a variety of different sizes and shapes, also on multiscale and multisensor data, such as buildings, architectural complexes, data from UAV surveys and so on
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