Development Methods and a Scenegraph Animation API for Cluster Driven Immersive Applications

This paper presents a scenegraph animation application programming interface (API), known as the Animation Engine, which was constructed for software developers to easily perform smooth transitions and manipulations to scenegraph nodes. A developer can use one line of code to enter the property, end state and number of frames to describe the animation, then the Animation Engine handles the rest in the background. The goal of the Animation Engine is to provide a simple API that integrates into existing applications with minimal effort. Additionally, techniques to improve virtual reality (VR) application performance on a large computer cluster are presented. These techniques include maintaining high frame rates with 4096 × 4096 pixel textures, eliminating extraneous network traffic and reducing long model loading time. To demonstrate the Animation Engine and the development techniques, an application known as the Virtual Universe was created. The Virtual Universe, designed to run in a six walled CAVE, allows users to freely explore a set of space themed environments. The architecture and development techniques for writing a stable immersive VR application on a large computer cluster, in addition to the creation of the Animation Engine, is presented in this paper

3D mesh metamorphosis from spherical parameterization for conceptual design

Engineering product design is an information intensive decision-making process that consists of several phases including design specification definition, design concepts generation, detailed design and analysis, and manufacturing. Usually, generating geometry models for visualization is a big challenge for early stage conceptual design. Complexity of existing computer aided design packages constrains participation of people with various backgrounds in the design process. In addition, many design processes do not take advantage of the rich amount of legacy information available for new concepts creation. The research presented here explores the use of advanced graphical techniques to quickly and efficiently merge legacy information with new design concepts to rapidly create new conceptual product designs. 3D mesh metamorphosis framework 3DMeshMorpher was created to construct new models by navigating in a shape-space of registered design models. The framework is composed of: i) a fast spherical parameterization method to map a geometric model (genus-0) onto a unit sphere; ii) a geometric feature identification and picking technique based on 3D skeleton extraction; and iii) a LOD controllable 3D remeshing scheme with spherical mesh subdivision based on the developedspherical parameterization. This efficient software framework enables designers to create numerous geometric concepts in real time with a simple graphical user interface. The spherical parameterization method is focused on closed genus-zero meshes. It is based upon barycentric coordinates with convex boundary. Unlike most existing similar approaches which deal with each vertex in the mesh equally, the method developed in this research focuses primarily on resolving overlapping areas, which helps speed the parameterization process. The algorithm starts by normalizing the source mesh onto a unit sphere and followed by some initial relaxation via Gauss-Seidel iterations. Due to its emphasis on solving only challenging overlapping regions, this parameterization process is much faster than existing spherical mapping methods. To ensure the correspondence of features from different models, we introduce a skeleton based feature identification and picking method for features alignment. Unlike traditional methods that align single point for each feature, this method can provide alignments for complete feature areas. This could help users to create more reasonable intermediate morphing results with preserved topological features. This skeleton featuring framework could potentially be extended to automatic features alignment for geometries with similar topologies. The skeleton extracted could also be applied for other applications such as skeleton-based animations. The 3D remeshing algorithm with spherical mesh subdivision is developed to generate a common connectivity for different mesh models. This method is derived from the concept of spherical mesh subdivision. The local recursive subdivision can be set to match the desired LOD (level of details) for source spherical mesh. Such LOD is controllable and this allows various outputs with different resolutions. Such recursive subdivision then follows by a triangular correction process which ensures valid triangulations for the remeshing. And the final mesh merging and reconstruction process produces the remeshing model with desired LOD specified from user. Usually the final merged model contains all the geometric details from each model with reasonable amount of vertices, unlike other existing methods that result in big amount of vertices in the merged model. Such multi-resolution outputs with controllable LOD could also be applied in various other computer graphics applications such as computer games

The Application of Polynomial Response Surface and Polynomial Chaos Expansion Metamodels within an Augmented Reality Conceptual Design Environment

The engineering design process consists of many stages. In the conceptual phase, potential designs are generated and evaluated without considering specifics. Winning concepts then advance to the detail design and high fidelity simulation stages. At this point in the process, very accurate representations are made for each design and are then subjected to rigorous analysis. With the advancement of computer technology, these last two phases have been very well served by the software community. Engineering software such as computer-aided design (CAD), finite element analysis (FEA), and computational fluid dynamics (CFD) have become an inseparable part of the design process for many engineered products and processes. Conceptual design tools, on the other hand, have not undergone this type of advancement, where much of the work is still done with little to no digital technology. Detail oriented tools require a significant amount of time and training to use effectively. This investment is considered worthwhile when high fidelity models are needed. However, conceptual design has no need for this level of detail. Instead, rapid concept generation and evaluation are the primary goals. Considering the lack of adequate tools to suit these needs, new software was created. This thesis discusses the development of that conceptual design application. Traditional design tools rely on a two dimensional mouse to perform three dimensional actions. While many designers have become familiar with this approach, it is not intuitive to an inexperienced user. In order to enhance the usability of the developed application, a new interaction method was applied. Augmented reality (AR) is a developing research area that combines virtual elements with the real world. This capability was used to create a three dimensional interface for the engineering design application. Using specially tracked interface objects, the user\u27s hands become the primary method of interaction. Within this AR environment, users are able perform many of the basic actions available within a CAD system such as object manipulation, editing, and assembly. The same design environment also provides real time assessment data. Calculations for center of gravity and wheel loading can be done with the click of a few buttons. Results are displayed to the user in the AR scene. In order to support the quantitative analysis tools necessary for conceptual design, additional research was done in the area of metamodeling. Metamodels are capable of providing approximations for more complex analyses. In the case of the wheel loading calculation, the approximation takes the place of a time consuming FEA simulation. Two different metamodeling techniques were studied in this thesis: polynomial response surface (PRS) and polynomial chaos expansion (PCE). While only the wheel loading case study was included in the developed application, an additional design problem was analyzed to assess the capabilities of both methods for conceptual design. In the second study, the maximum stresses and displacements within the support frame of a bucket truck were modeled. The source data for building the approximations was generated via an FEA simulation of digital mockups, since no legacy data was available. With this information, experimental models were constructed by varying several factors, including: the distribution of source and test data, the number of input trials, the inclusion of interaction effects, and the addition of third order terms. Comparisons were also drawn between the two metamodeling techniques. For the wheel loading models, third order models with interaction effects provided a good fit of the data (root mean square error of less than 10%) with as few as thirty input data points. With minimal source data, however, second order models and those without interaction effects outperformed third order counterparts. The PRS and PCE methods performed almost equivalently with sufficient source data. Difference began to appear at the twenty trial case. PRS was more suited to wider distributions of data. The PCE technique better handled smaller distributions and extrapolation to larger test data. The support frame problem represented a more difficult analysis with non-linear responses. While initial third order results from the PCE models were better than those for PRS, both had significantly higher error than in the previous case study. However, with simpler second order models and sufficient input data (more than thirty trials) adequate approximation results were achieved. The less complex responses had error around 10%, and the model predictions for the non-linear response were reduced to around 20%. These results demonstrate that useful approximations can be constructed from minimal data. Such models, despite the uncertainty involved, will be able to provide designers with helpful information at the conceptual stage of a design process

Plataforma para a configuração de ambientes virtuais interativos

Mestrado em Sistemas de InformaçãoThis dissertation presents the creation of the Platform for Setting-up Interactive Virtual Environments (pSIVE). Bearing in mind the difficulty required to create virtual environments, the platform aims to allow non-specialists to benefit from virtual environments in applications such as virtual tours as marketing or training where one could interact with elements of the environment to extract contextual information. For this, several frameworks and technologies possible of been integrated into the platform are presented, as well as which ones are more suitable. The platform allows users, from a configuration tool, to create virtual environments and set up their aspects, modes of interaction and what hardware to use. The construction of the world is done by loading 3D models and associating multimedia information (videos, texts or PDF documents) to them. Alongside its development, a comparative study between two ray-tracing selection techniques was performed. Based on the results analysis, it is suggested which technique better fits the environments created with pSIVE. The study also demonstrates the flexibility of the platform, since it was adapted to serve as a test environment. A case of study is introduced where a step by step configuration of a virtual environment is shown, as well as its use within the PRODUTECH-PTI project. Finally, the conclusions are drawn, and suggestions for future work are presented.Este trabalho apresenta a criação da Plataforma para Configuração de Ambientes Virtuais Interativos (com o acrónimo em Inglês pSIVE). Tendo em mente a dificuldade necessária para a criação de ambientes virtuais, a plataforma tem como objectivo possibilitar a não especialistas tirarem proveito de ambientes virtuais, em aplicações genéricas, como por exemplo visitas virtuais que sirvam como publicidade ou treino onde seja possível interagir com elementos do ambiente para extrair informação contextualizada. Para isto apresenta-se um levantamento de tecnologias e frameworks passíveis de serem envolvidos no processo de criação e justifica-se a escolha dos mais adequados para integrar a plataforma. A plataforma permite que utilizadores, a partir de uma ferramenta de configuração, criem ambientes virtuais e seus aspectos, bem como modos de interação e indiquem o hardware a ser utilizado. Para a construção do mundo, é possível carregar modelos 3D associando-lhes informação multimédia (Vídeos, Textos ou Documentos PDF). Paralelamente ao desenvolvimento da plataforma, foi realizado um estudo comparativo entre duas técnicas de seleção por ray-tracing, que diferem quanto à origem do feixe. A análise dos resultados sugere qual técnica que melhor se adequa aos ambientes criados. O estudo também demonstra a flexibilidade da plataforma, uma vez que esta foi adaptada para servir como ambiente de teste. Apresenta-se ainda um caso de estudo, onde se mostra passo a passo a configuração de um ambiente virtual e a sua utilização no âmbito do projeto PRODUTECH-PTI. Por fim, são apresentadas conclusões e possíveis caminhos a serem seguidos para a evolução futura do trabalho

ASCR/HEP Exascale Requirements Review Report

This draft report summarizes and details the findings, results, and recommendations derived from the ASCR/HEP Exascale Requirements Review meeting held in June, 2015. The main conclusions are as follows. 1) Larger, more capable computing and data facilities are needed to support HEP science goals in all three frontiers: Energy, Intensity, and Cosmic. The expected scale of the demand at the 2025 timescale is at least two orders of magnitude -- and in some cases greater -- than that available currently. 2) The growth rate of data produced by simulations is overwhelming the current ability, of both facilities and researchers, to store and analyze it. Additional resources and new techniques for data analysis are urgently needed. 3) Data rates and volumes from HEP experimental facilities are also straining the ability to store and analyze large and complex data volumes. Appropriately configured leadership-class facilities can play a transformational role in enabling scientific discovery from these datasets. 4) A close integration of HPC simulation and data analysis will aid greatly in interpreting results from HEP experiments. Such an integration will minimize data movement and facilitate interdependent workflows. 5) Long-range planning between HEP and ASCR will be required to meet HEP's research needs. To best use ASCR HPC resources the experimental HEP program needs a) an established long-term plan for access to ASCR computational and data resources, b) an ability to map workflows onto HPC resources, c) the ability for ASCR facilities to accommodate workflows run by collaborations that can have thousands of individual members, d) to transition codes to the next-generation HPC platforms that will be available at ASCR facilities, e) to build up and train a workforce capable of developing and using simulations and analysis to support HEP scientific research on next-generation systems.Comment: 77 pages, 13 Figures; draft report, subject to further revisio

Real-Time Visualization for Prevention of Excavation Related Utility Strikes.

An excavator unintentionally hits a buried utility every 60 seconds in the United States, causing several fatalities and injuries, and billions of dollars in damage each year. Most of these accidents occur either because excavator operators do not know where utilities are buried, or because they cannot perceive where the utilities are relative to the digging excavator. In particular, an operator has no practical means of knowing the distance of an excavator’s digging implement (e.g. bucket) to the nearest buried obstructions until they are visually exposed, which means that the first estimate of proximity an operator receives is often after the digging implement has already struck the buried utility. The objective of this dissertation was to remedy this situation and explore new proximity monitoring methods for improving the spatial awareness and decision-making capabilities of excavator operators. The research pursued fundamental knowledge in equipment articulation monitoring, and geometric proximity interpretation, and their integration for improving spatial awareness and operator knowledge. A comprehensive computational framework was developed to monitor construction activities in real-time in a concurrent 3D virtual world. As an excavator works, a geometric representation of the real ongoing process is recreated in the virtual environment using 3D models of the excavator, buried utilities and jobsite terrain. Data from sensors installed on the excavator is used to update the position and orientation of the corresponding equipment in the virtual world. Finally, geometric proximity monitoring and collision detection computations are performed between the equipment end-effector and co-located buried utility models to provide distance and impending collision information to the operator, thereby realizing real time knowledge-based excavator operation and control. The outcome of this research has the potential to transform excavator operation from a primarily skill-based activity to a knowledge-based practice, leading to significant increases in construction productivity and safety. This is turn is expected to help realize tangible cost savings and reduction of potential hazards to citizens, improvement in competitiveness of U.S. industry, and reduction in life cycle costs of underground infrastructure.PHDCivil EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/96133/1/stalmaki_1.pd