Remote Execution for 3D Graphics

Mobile clients such as PDAs, laptops, wrist watches, smart phones are rapidly emerging in the consumer market and an increasing number of graphics applications are being developed for them. However, current hardware technology limits the processing power on these mobile devices and wireless network bandwidth can be scarce and unreliable. A modern photorealistic graphics application is resource-hungry, consumes large amounts of cpu cycles, memory and network bandwidth if distributed. Besides running them on mobile devices may also diminish their battery power in the process. Bulk of graphics computations involve floating point operations and the lack of hardware support for such on PDAs imposes further restrictions. Remote execution, wherein part or the entire rendering process is offloaded to a powerful surrogate server is an attractive solution. We propose pipeline-splitting, a paradigm whereby 15 sub-stages of the graphics pipeline are isolated and instrumented with networking code such that it can run on either a graphics client or a surrogate server. To validate our concepts, we instrument Mesa3D, a popular implementation of the OpenGL graphics to support pipeline-splitting, creating Remote Mesa (RMesa). We further extend the Remote Execution model to provide an analytical model for predicting the rendering time and memory consumption involved in Remote Execution. Mobile devices have limited battery power. Therefore, it is important to understand if during Remote Execution, communication is more power consuming than computation. In order to study the same, we develop PowerSpy, a Real Time Power Profiler for I/O devices and applications. Finally, we add Remote Execution to an existing Distributed Graphics Framework targeted for mobile devices, namely, MADGRAF. In addition to Remote Execution, MADGRAF has another policy known as the Transcoder Based Approach in which the original 3D graphics image is modified to suite the mobile devices\u27 rendering capacity. Though this speeds up the rendering process, it affects photorealism. We propose an intelligent runtime decision making engine, Intelligraph, which evaluates the runtime performance of the mobile client and decides between Remote Execution and the Transcoder Based Approach

Using GeoTools to Implement the Multi -Criteria Evaluation Analysis : Weighted Linear Combination Model

Multi-Criteria Evaluation Analysis (MCEA) is a decision making method employed to solve optimization problems that require the evaluation of a set of criteria to build an optimal decision. Where MCEA is integrated with GIS, optimization problems with spatial aspects, such as finding the best location of a facility across an area, could be solved. MCEA is implemented through different criteria decision rules among of which is the Weighted Linear Combination (WLC) which has five different phases: 1) criteria definition, 2) criteria normalization, 3) weights definition, 4) criteria weighting, and 5) weighted criteria sum-overlaying. Free and Open Source GIS Software (FOSS GIS) is getting more popular. Indicators on this popularity include: 1) the number of governmentally funded projects, 2) the number of downloads, 3) and the increasing number of use cases of open source GIS software. Some governments have even decided to replace their proprietary software with FOSS software. Implementation of MCEA models in GIS software varied among loose-coupling, tight-coupling, and full-integration. In loose-coupling, GIS and MCEA are coupled through a file exchange mechanism. In tight-coupling, both systems share a common interface. In full-integration, custom programming scripts could be written to implement different MCEA tasks and models. Previous studies showed that most GIS software have limited capabilities to perform MCEA except for IDRISI, Common GIS, ILWIS, and TNT-GIS. Among of them, only ILWIS is an open source software distributed under GPL license. In this thesis, a desktop computer application, MC-Analyst, has been developed using GeoTools, a Java open source GIS software library, Java SE 1.7, and NetBeans IDE 7.3 to implement MCEA-WLC model. The milestone works of the thesis included: 1) The feasibility of using FOSS in general and FOSS GIS in specific was researched, 2) A survey of the literature that researched previous efforts and implementations for integrating MCEA in GIS software was carried out, 3) Experiencing software development using a FOSS GIS library, GeoTools, in order to address strength and weakness points for development using GeoTools and FOSS GIS, and 4) Some recommendations concerning future development approaches to produce better integrated MCEA and FOSS GIS systems were addressed for future works. To test MC-Analyst, a previous case study that located best sites to build solar farms in Colorado was employed. The output of the case study application was examined by altering input criteria weights for the main layers of solar DNI, distance to transmission lines, and distance to primary roads in the GIS-MCEA/WLC model. Different outputs found as expected that when a higher weight had been given to one criterion, the final suitability result showed noticeable higher suitability in areas where that factor was considered optimal. Raster and vector data processing capabilities of GeoTools were explored to perform basic GIS functions and it showed strong support for such functions. It was also found that in order for MC-Analyst to work as a standalone fully integrated Multi-Criteria Spatial Decision Support System (MC-SDSS), it would require other tasks that are found in common desktop GIS applications such as re-projection, clipping, and resampling. Therefore, re-using the source code of an open source desktop GIS application such as uDig or gvSig and integrate the developed MCEA-WLC model with it to produce fully integrated MC-SDSS could be of great interest for future development for FOSS GIS community. This would create an effective product that might compete with effective proprietary GIS software that implements MCEA models. The study showed also that before choosing a software library to start with, the development team should be acquainted with other possible open source and free software applications and libraries in order for the development process to be smooth and to output a productive application.Optimization problems exist in many disciplines. Regardless of the field in which the optimal solution is sought, all optimization problems share a common nature; seeking the best possible solution that must meet a set of criteria which are defined by a group of experts or professional shareholders in the field of the optimization problem. Therefore, by combining an optimal solution seeking methodology (Evaluation Analysis) and the multiple criteria of the problem (Multi-Criteria), a new term emerged, Multi-Criteria Evaluation Analysis (MCEA). MCEA is used with Geographic Information Systems (GIS is an information system that stores, processes, analyzes, and presents geographic information) to solve optimization problems that have a spatial nature such as finding optimal locations for some kind of facility or activity. Some implementation of MCEA models have existed in some GIS packages. IDRISI, Common GIS, ILWIS, and TNT-GIS are major GIS software that provided some kind of implementation of MCEA models. Among the four GIS software, only ILWIS is a Free and Open Source Software (FOSS). FOSS GIS is getting more popular. Indicators on this popularity were listed in the thesis. As FOSS GIS is getting more popular, a great potential of MCEA implementation is found in FOSS GIS. In this thesis, a desktop computer application, MC-Analyst, has been developed using GeoTools, an open source GIS development kit, to implement a MCEA model. MC-Analyst benefited from GeoTools's strong support for basic GIS functions that made MCEA model implementation easier. To test MC-Analyst, a previous case study that investigated a spatial optimization problem to evaluate Colorado landscape to locate best sites for solar energy farms in Colorado was employed. The different outputs that resulted from different inputs to MC-Analyst were analyzed and found as expected. The study demonstrated FOSS integration and concluded that developing a fully-integrated and competent spatial decision support system could be of great interest for future development for FOSS GIS community. The study also concluded the necessity for a developer to be acquainted with other possible and different FOSS GIS software components in order for the development process to be smooth and to output productive applications

Improving Collaborative Drawing using HTML5

This research looks into improving online web-based collaborative drawing using HTML5. Although many systems have been developed over a number of years, none of the applications released have been satisfactory for many artists; the core drawing experience was too different from a stand-alone drawing applications. Stand-alone drawing applications have better freedom of control with functions like undo and allow artists to work efficiently with hotkeys. The advent of the HTML5 Canvas Element and Websockets in recent browsers has provided new opportunities for collaborative online interaction. This research used an incremental development approach to build a prototype HTML5 drawing application providing new functionality for online collaborative drawing. The project was supported by two experienced artists throughout investigation, design, implementation and testing. The project artists helped validate design decisions and evaluate the implementation. As a result, a robust HTML5 collaborative drawing application was built. The prototype contains core drawing functionality that existing applications did not. Features include: undo and redo, free canvas transformation, complex hotkey interaction, custom canvas size support, colour wheel, and layers. All these features work smoothly in a fully synchronized network environment under a client-server model. The collaboration system uses an authoritative server structure with local prediction and re-synchronization to hide latency. Although the result is only a prototype, the evaluations from the project artists were very positive. Once more functionality targeted towards social interaction is built, the prototype will be ready for mass public testing. Although there are some issues caused by the immaturity of HTML5 technology, this project affirms its capability for collaborative web applications

Distributed GIS for Monitoring and Modeling Urban Air Quality

The progress of technology has made the measurement of air quality and the simulation of complex air pollution models both feasible and cost-effective. However, there is a long way to go in terms of facilitating widespread access to the data and models, and linking the monitoring of trace gases with specific urban activities and land use that might be controllable. As part of a NASA-funded project, we are working with scientists and engineers to design and test a distributed GIS infrastructure for studying such "urban respiration" phenomena. Measurements of trace gases within a metropolitan area (from mobile and fixed instruments) are geo-referenced, time-stamped, and stored in a relational database server (Oracle). GIS services (using ArcInfo and ArcView) are connected to the database so that subsets of the trace gas measurements can be extracted and converted on-the-fly into GIS data layers. These subsets (by location, date, and time-of-day) can be displayed and cross-referenced with other layers such as weather conditions, land use and cover, topography, hydrography, demography, and congestion levels of road networks. A web-based interface (using ArcView Internet Map Server) allows research team members at different locations to query, visualize, and process the cross-referenced data layers in order to generate surface level estimates of initial conditions for use in the air quality models.NAS

Map Generation from Large Scale Incomplete and Inaccurate Data Labels

Accurately and globally mapping human infrastructure is an important and challenging task with applications in routing, regulation compliance monitoring, and natural disaster response management etc.. In this paper we present progress in developing an algorithmic pipeline and distributed compute system that automates the process of map creation using high resolution aerial images. Unlike previous studies, most of which use datasets that are available only in a few cities across the world, we utilizes publicly available imagery and map data, both of which cover the contiguous United States (CONUS). We approach the technical challenge of inaccurate and incomplete training data adopting state-of-the-art convolutional neural network architectures such as the U-Net and the CycleGAN to incrementally generate maps with increasingly more accurate and more complete labels of man-made infrastructure such as roads and houses. Since scaling the mapping task to CONUS calls for parallelization, we then adopted an asynchronous distributed stochastic parallel gradient descent training scheme to distribute the computational workload onto a cluster of GPUs with nearly linear speed-up.Comment: This paper is accepted by KDD 202

Visibility computation through image generalization

This dissertation introduces the image generalization paradigm for computing visibility. The paradigm is based on the observation that an image is a powerful tool for computing visibility. An image can be rendered efficiently with the support of graphics hardware and each of the millions of pixels in the image reports a visible geometric primitive. However, the visibility solution computed by a conventional image is far from complete. A conventional image has a uniform sampling rate which can miss visible geometric primitives with a small screen footprint. A conventional image can only find geometric primitives to which there is direct line of sight from the center of projection (i.e. the eye) of the image; therefore, a conventional image cannot compute the set of geometric primitives that become visible as the viewpoint translates, or as time changes in a dynamic dataset. Finally, like any sample-based representation, a conventional image can only confirm that a geometric primitive is visible, but it cannot confirm that a geometric primitive is hidden, as that would require an infinite number of samples to confirm that the primitive is hidden at all of its points. ^ The image generalization paradigm overcomes the visibility computation limitations of conventional images. The paradigm has three elements. (1) Sampling pattern generalization entails adding sampling locations to the image plane where needed to find visible geometric primitives with a small footprint. (2) Visibility sample generalization entails replacing the conventional scalar visibility sample with a higher dimensional sample that records all geometric primitives visible at a sampling location as the viewpoint translates or as time changes in a dynamic dataset; the higher-dimensional visibility sample is computed exactly, by solving visibility event equations, and not through sampling. Another form of visibility sample generalization is to enhance a sample with its trajectory as the geometric primitive it samples moves in a dynamic dataset. (3) Ray geometry generalization redefines a camera ray as the set of 3D points that project at a given image location; this generalization supports rays that are not straight lines, and enables designing cameras with non-linear rays that circumvent occluders to gather samples not visible from a reference viewpoint. ^ The image generalization paradigm has been used to develop visibility algorithms for a variety of datasets, of visibility parameter domains, and of performance-accuracy tradeoff requirements. These include an aggressive from-point visibility algorithm that guarantees finding all geometric primitives with a visible fragment, no matter how small primitive\u27s image footprint, an efficient and robust exact from-point visibility algorithm that iterates between a sample-based and a continuous visibility analysis of the image plane to quickly converge to the exact solution, a from-rectangle visibility algorithm that uses 2D visibility samples to compute a visible set that is exact under viewpoint translation, a flexible pinhole camera that enables local modulations of the sampling rate over the image plane according to an input importance map, an animated depth image that not only stores color and depth per pixel but also a compact representation of pixel sample trajectories, and a curved ray camera that integrates seamlessly multiple viewpoints into a multiperspective image without the viewpoint transition distortion artifacts of prior art methods

A WebGL application based on BIM IFC

Dissertação apresentada à Universidade Fernando Pessoa como partes dos requisitos para a obtenção do grau de Mestre em Engenharia Informática, ramo de Computação MóvelThe possibility of displaying high performance 3D accelerated graphics in the browser is seen as an obstacle to the conversion of applications to the web. The release of WebGL made Web3D gain new strength to overcome that obstacle. Architecture, Engineering and Construction (AEC) tools are a type of applications that could benefit with this advance. In the AEC industry, there is a standard candidate for Building Information Modelling (BIM), called Industry Foundation Classes (IFC). This data model promotes interoperability between AEC tools, giving a common format to the applications. This work comes from the need of redesigning a legacy application that allows the user to design, display and calculate building structures. Focusing on the displaying of building structures, this work merges IFC and WebGL into an application, to replicate in a modern way the legacy application capabilities. This is done by developing a server module that processes the IFC data model and a client module that displays that model in a WebGL environment. The result is a prototype web application capable of displaying 3D IFC building models in the browser without plug-ins. A possibilidade de visualização de gráficos acelerados 3D de alto desempenho no navegador ainda é visto como um obstáculo na migração de aplicações para a web. O lançamento do WebGL fez o Web3D ganhar uma nova força para superar esse obstáculo. As ferramentas de Arquitetura, Engenharia e Construção (AEC) são um tipo de aplicações que podem beneficiar com este avanço. Na indústria AEC, há um candidato a padrão para Building Information Modelling (BIM), chamado de Industry Foundation Classes (IFC). Este modelo de dados promove a interoperabilidade entre as ferramentas de AEC, fornecendo um formato comum às aplicações. Este trabalho surge da necessidade de redesenhar uma aplicação legada que permite ao o utilizador projetar, visualizar e calcular estruturas de edifícios. Focando na visualização de estruturas de edifícios, este trabalho funde o IFC e o WebGL numa aplicação, para replicar de forma moderna as capacidades da aplicação legada. Isto é feito através do desenvolvimento de um módulo de servidor que processa o modelo de dados IFC e um módulo de cliente que mostra esse modelo num ambiente WebGL. O resultado é um protótipo duma aplicação web capaz de visualizar modelos 3D de edifícios em formato IFC no browser sem plug-ins