Browsing by Subject "3D"
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Item 3D interactive pictorial maps(Texas A&M University, 2005-02-17) Naz, AsmaThe objective of my research is to revive and practice the art of traditional pictorial maps in 3D cartographic visualization. I have chosen to create both graphical and statistical pictorial maps which can be used for the purpose of tourism and data representation respectively. Some traditional hand-drawn and sculptural pictorial maps of famous artists have been picked out to start as a base for my work. The goal was to recreate or imitate the style, character and features of these traditional hand-drawn and sculptural maps with 3D computer graphics and to analyze how effectively 3D tools can be used to communicate map information. I also wanted to explore ways to make these maps interactive on the Web and have them accessible to a large number of viewers. The results show a number of interactive 3D pictorial maps of different countries and continents. These maps are initially built with Maya, a 3D modeling software, and converted into web pages using the Viewpoint Technology. For statistical maps, Mel scripts have been used in Maya to take input from the user and change the shape of models accordingly to represent data. These maps are interactive and navigable and are designed to be easily accessible on the Web.Item A new graphical user interface for a 3D topological mesh modeler(Texas A&M University, 2008-10-10) Morris, David VictorIn this thesis, I present a new platform-independent, open source, intuitive graphical user interface for TopMod, an application designed for interacting with 3-dimensional manifold meshes represented by a Doubly Linked Face List (DLFL). This new interface, created using the Trolltech Qt user interface library, enables users to construct and interact with complex manifold meshes much faster and more easily than was previously possible. I also present a method for the rapid creation of a successful online community of users and developers, by integrating a variety of open source web-based software packages. The new website, which includes a discussion forum, a news blog, a collaborative user and developer wiki, and a source code repository and release manager, received an average of 250 unique visits per day during the first two months of its existence, and it continues to be utilized by a variety of users and developers worldwide.Item Acquisition and reconstruction of brain tissue using knife-edge scanning microscopy(Texas A&M University, 2004-09-30) Mayerich, David MatthewA fast method for gathering large-scale data sets through the serial sectioning of brain tissue is described. These data sets are retrieved using knife-edge scanning microscopy, a new technique developed in the Brain Networks Laboratory at Texas A&M University. This technique allows the imaging of tissue as it is cut by an ultramicrotome. In this thesis the development of a knife-edge scanner is discussed as well as the scanning techniques used to retrieve high-resolution data sets. Problems in knife-edge scanning microscopy, such as illumination, knife chatter, and focusing are discussed. Techniques are also shown to reduce these problems so that serial sections of tissue can be sampled at resolutions that are high enough to allow reconstruction of neurons at the cellular level.Item An Automated System for the Creation of Articulated Mechanical Parts(2010-07-14) Wheeler, Christopher R.Proposes a new method to model the geometric form of articulated mechanical parts while simultaneously testing their range of motion in relation to other nearby parts. Utilizing a database of mechanical parts in virtual three-dimensional form, a software tool assists users in quickly building a complex high-level mechanical object which can be placed directly into a visual effects production pipeline. The tool creates a workflow that allows modeling and rigging problems to be solved concurrently within the same interface. Optimized animation controls are generated automatically to expedite the rigging process. A system of standardization provides a framework for each part?s functionality within the hierarchy of each new assembly, while also guaranteeing reusability and backwards compatibility with all other assemblies created with this tool. A prototype has been developed as a plug-in to existing commercial software to showcase the described methodology. This prototype provides a unique solution to common modeling and rigging problems in the field of visual effects and animation.Item Automated Vehicle Articulation and Animation: A Maxscript Approach(2011-02-22) Griffin, Christopher CoreyThis thesis presents an efficient, animation production-centric solution to the articulation and animation of computer generated automobiles for creating animations with a high degree of believability. The thesis has two main foci which include an automated and customizable articulation system for automobile models and a vehicle animation system that utilizes minimal simulation techniques. The primary contribution of this thesis is the definition of a computer graphics animation software program that utilizes simulation and key-frame methods for defining vehicle motion. There is an emphasis on maintaining efficiency to prevent long wait times during the animation process and allow for immediate interactivity. The program, when implemented, allows for animation of a vehicle with minimal input and setup. These automated tools could make animating an automobile, or multiple automobiles of varying form and dimensions much more efficient and believable in a film, animation, or game production environment.Item Creation of Chimera Through the Usage of an Inspirational System(2013-04-23) Parish, Brandi NicoleMy thesis involves studying the nature of chimera through history and how certain aspects of chimeras represent specific features of dualities in human nature. The research was reflected in a series of sketches, where one sketch was finalized into a fully realized 3D model. To aid in this goal, I created a system that will randomly generate chimera based on different characteristics. This system was created using Max 5, and was programmed to place images with alphas on top of each other to create unique chimeras. The variables within this system are derived from the research on chimeras depicted in art and mythology throughout history, and will be used as an inspirational tool to help generate unique combinations of chimeras that may not otherwise have been imagined.Item Creative Character Design Based on Combination of 2D and 3D Characteristics(2014-12-09) Salimi Beni, AnahitaThis research combines the need for innovation in character design with the idea of combining 2D and 3D characteristics to create an original and appealing character style. The goal has been to benefit from the capabilities of 3D animation while implementing the simplicity of 2D designs. I studied character design and analyzed examples of existing animated characters followed by experiments with different approaches to combining 2D and 3D character elements. Based on the results of these experiments, I designed a set of characters that combine both 2D and 3D components. These characters have been rigged, animated and rendered to demonstrate their functionality.Item Efficient Smoothing and Interpolation of Velocity Models for Seismic Wavefront Construction Algorithms(2012-10-19) Chen, BoThe wavefront construction (WFC) method is an effective tool to compute seismic ray fields and has wide applications. This paper applies the WFC method to a heterogeneous earth model represented as a 3-D grid instead of a sequence of smooth layers, as the layered model is insufficient for the regions with complex geological structures. In order to utilize gridded models, highly heterogeneous models must be smoothed for reliable numerical results. A new velocity gradient smoothing method is proposed that is able to control quantitatively the smoothness of the velocity model while preserving the main structural characteristics of the original model. A modified inverse distance weighting method is applied to obtain velocities or densities at an arbitrary point in the model for successive wavefront propagation. A very complex 3-D grid model based on the standard Marmousi reference model is tested to compare the new approach to alternative smoothing schemes, and the first arrival travel times from the WFC method are compared with results from an eikonal solver. These results are obtained more quickly, but the algorithm is restricted to computing only first arrivals. However, comparison helps to establish the accuracy of the WFC solutions and assess the influence of the smoothing schemes. The modeling comparisons verify the effectiveness of the proposed smoothing methods and the enhanced performance of the WFC algorithm with the 3-D grid model.Item Human detection and action recognition using depth information by Kinect(2012-05) Xia, Lu, active 21st century; Grauman, Kristen Lorraine, 1979-Traditional computer vision algorithms depend on information taken by visible-light cameras. But there are inherent limitations of this data source, e.g. they are sensitive to illumination changes, occlusions and background clutter. Range sensors give us 3D structural information of the scene and it’s robust to the change of color and illumination. In this thesis, we present a series of approaches which are developed using the depth information by Kinect to address the issues regarding human detection and action recognition. Taking the depth information, the basic problem we consider is to detect humans in the scene. We propose a model based approach, which is comprised of a 2D head contour detector and a 3D head surface detector. We propose a segmentation scheme to segment the human from the surroundings based on the detection point and extract the whole body of the subject. We also explore the tracking algorithm based on our detection result. The methods are tested on a dataset we collected and present superior results over the existing algorithms. With the detection result, we further studied on recognizing their actions. We present a novel approach for human action recognition with histograms of 3D joint locations (HOJ3D) as a compact representation of postures. We extract the 3D skeletal joint locations from Kinect depth maps using Shotton et al.’s method. The HOJ3D computed from the action depth sequences are reprojected using LDA and then clustered into k posture visual words, which represent the prototypical poses of actions. The temporal evolutions of those visual words are modeled by discrete hidden Markov models (HMMs). In addition, due to the design of our spherical coordinate system and the robust 3D skeleton estimation from Kinect, our method demonstrates significant view invariance on our 3D action dataset. Our dataset is composed of 200 3D sequences of 10 indoor activities performed by 10 individuals in varied views. Our method is real-time and achieves superior results on the challenging 3D action dataset. We also tested our algorithm on the MSR Action3D dataset and our algorithm outperforms existing algorithm on most of the cases.Item Integrating 3D and 2D computer generated imagery for the comics medium(Texas A&M University, 2005-02-17) DeLuna, RubenAdvances in 3D computer technology have led to aesthetic experimentation within the comics medium. Comic creators have produced comic books done entirely with 3D models that are then assembled digitally for the printed page. However, in using these 3D objects in a comic format, the creators have developed art styles that do not adhere to the paradigms established by this traditionally 2D medium. More successful results can be achieved by integrating 3D computer generated imagery with traditional 2D imagery, rather than replacing it. This thesis develops a method of combining rendered 3D models with 2D vector graphics to create a comic book art style that is consistent with the traditional medium, while still taking advantage of the new technology.Item Multiazimuth velocity analysis using velocity-independent seismic imaging(2011-05) Burnett, William Andrew, 1983-; Fomel, Sergey B.; Stoffa, Paul L., 1948-Multiazimuth seismic data contains information about how the Earth’s seismic response changes with azimuthal direction. Directional-dependence of the seismic response can be caused by anisotropy or heterogeneity, associated with subsurface features such as fractures, stresses, or structure. Characterizing azimuthal variations is done through velocity analysis, which provides a link between an acquired data set and its image, as well as between the image and subsurface geology. At the stage which conventional velocity analysis is applied, it is difficult to distinguish the geologic cause of observed azimuthal velocity variations. The inability to distinguish the similar effects of anisotropy and heterogeneity leads to positioning errors in the final image and velocity estimates. Regardless of the cause, azimuthally variable velocities require at least three parameters to characterize, as opposed to the conventional single-parameter isotropic velocity. The semblance scan is the conventional tool for seismic velocity analysis, but it was designed for the isotropic case. For multiple parameters, the semblance scan becomes computationally impractical. In order to help address the xiissues of geologic ambiguity and computational efficiency, I develop three methods for multiazimuth seismic velocity analysis based on “velocity-independent” imaging techniques. I call this approach, velocity analysis by velocity-independent imaging, where I reverse the conventional order of velocity estimation followed by image estimation. All three methods measure time-domain effective-velocity parameters. The first method, 3D azimuthally anisotropic velocity-independent NMO, replaces the explicit measurement of velocity with local slope detection. The second method, time-warping, uses local slope information to predict traveltime surfaces without any moveout assumption beforehand, and then fit them with a multiparameter velocity model. The third method, azimuthal velocity continuation, uses diffraction image focusing as a velocity analysis criterion, thereby performing imaging and velocity analysis simultaneously. The first two methods are superior to the semblance scan in terms of computational efficiency and their ability to handle multi-parameter models. The third method is similar to a single multi-parameter semblance scan in computational cost, but it helps handle the ambiguity between structural heterogeneity and anisotropy, which leads to better positioned images and velocity estimates.Item Physics-Based 3D Multi-Directional Reloading Algorithm for Deep Burn HTR Prismatic Block Systems(2011-10-21) Lewis, Tom Goslee, IIITo assure nuclear power sustainability, ongoing efforts on advanced closed-fuel cycle options and adapted open cycles have led to investigations of various strategies involving utilization of Transuranic (TRU) nuclides in nuclear reactors. Due to favorable performance characteristics, multiple studies are focused on transmutation options using High Temperature Gas-cooled Reactors (HTGRs). Prismatic HTGRs allow for 3-Dimensional (3D) fuel shuffling and prior shuffling algorithms were based on experimental block movement and/or manual block shuffle patterns. In this dissertation, a physics based 3D multi-directional reloading algorithm for prismatic deep burn very high temperature reactors (DB-VHTRs) was developed and tested to meet DB-VHTR operation constraints utilizing a high fidelity neutronics model developed for this dissertation. The high fidelity automated neutronics model allows design flexibility and metric tracking in spatial and temporal dimensions. Reduction of TRUs in DB-VHTRs utilizing full vectors of TRUs from light water reactor spent nuclear fuel has been demonstrated for both a single and two-fuel composition cores. Performance of the beginning-of-life and end-of-life (EOL) domains for multi-dimensional permutations were evaluated. Utilizing a two-fuel assembly permutation within the two-fuel system domain for a Single-Fuel vector, the developed shuffling algorithm for this dissertation has successfully been tested to meet performance objectives and operation constraints.Item Pixel Noir: a style for cinematic computer-generated lighting(Texas A&M University, 2006-04-12) Han, LeiThis thesis provides an example of creating a special cinematic style of Film Noir in computer-generated animation. The thesis is designed as a discussion of how a unique lighting style in computer graphics can be used to enhance visual storytelling for cinematic purposes. It provides digital filmmakers a beginning guide to deal with various lighting situations, and with cinematic lighting in 3D production.Item Recognizing human activity using RGBD data(2014-05) Xia, Lu, active 21st century; Aggarwal, J. K. (Jagdishkumar Keshoram), 1936-Traditional computer vision algorithms try to understand the world using visible light cameras. However, there are inherent limitations of this type of data source. First, visible light images are sensitive to illumination changes and background clutter. Second, the 3D structural information of the scene is lost when projecting the 3D world to 2D images. Recovering the 3D information from 2D images is a challenging problem. Range sensors have existed for over thirty years, which capture 3D characteristics of the scene. However, earlier range sensors were either too expensive, difficult to use in human environments, slow at acquiring data, or provided a poor estimation of distance. Recently, the easy access to the RGBD data at real-time frame rate is leading to a revolution in perception and inspired many new research using RGBD data. I propose algorithms to detect persons and understand the activities using RGBD data. I demonstrate the solutions to many computer vision problems may be improved with the added depth channel. The 3D structural information may give rise to algorithms with real-time and view-invariant properties in a faster and easier fashion. When both data sources are available, the features extracted from the depth channel may be combined with traditional features computed from RGB channels to generate more robust systems with enhanced recognition abilities, which may be able to deal with more challenging scenarios. As a starting point, the first problem is to find the persons of various poses in the scene, including moving or static persons. Localizing humans from RGB images is limited by the lighting conditions and background clutter. Depth image gives alternative ways to find the humans in the scene. In the past, detection of humans from range data is usually achieved by tracking, which does not work for indoor person detection. In this thesis, I propose a model based approach to detect the persons using the structural information embedded in the depth image. I propose a 2D head contour model and a 3D head surface model to look for the head-shoulder part of the person. Then, a segmentation scheme is proposed to segment the full human body from the background and extract the contour. I also give a tracking algorithm based on the detection result. I further research on recognizing human actions and activities. I propose two features for recognizing human activities. The first feature is drawn from the skeletal joint locations estimated from a depth image. It is a compact representation of the human posture called histograms of 3D joint locations (HOJ3D). This representation is view-invariant and the whole algorithm runs at real-time. This feature may benefit many applications to get a fast estimation of the posture and action of the human subject. The second feature is a spatio-temporal feature for depth video, which is called Depth Cuboid Similarity Feature (DCSF). The interest points are extracted using an algorithm that effectively suppresses the noise and finds salient human motions. DCSF is extracted centered on each interest point, which forms the description of the video contents. This descriptor can be used to recognize the activities with no dependence on skeleton information or pre-processing steps such as motion segmentation, tracking, or even image de-noising or hole-filling. It is more flexible and widely applicable to many scenarios. Finally, all the features herein developed are combined to solve a novel problem: first-person human activity recognition using RGBD data. Traditional activity recognition algorithms focus on recognizing activities from a third-person perspective. I propose to recognize activities from a first-person perspective with RGBD data. This task is very novel and extremely challenging due to the large amount of camera motion either due to self exploration or the response of the interaction. I extracted 3D optical flow features as the motion descriptor, 3D skeletal joints features as posture descriptors, spatio-temporal features as local appearance descriptors to describe the first-person videos. To address the ego-motion of the camera, I propose an attention mask to guide the recognition procedures and separate the features on the ego-motion region and independent-motion region. The 3D features are very useful at summarizing the discerning information of the activities. In addition, the combination of the 3D features with existing 2D features brings more robust recognition results and make the algorithm capable of dealing with more challenging cases.Item Style Transfer For Visual Storytelling A Case Study: The Hindu Mythological Character, Yamah, in the Style of the American Film Director, Tim Burton(2012-07-16) Perumalil, Ranjith ChandyIn this thesis, the concept of style transfer for visual storytelling is introduced. Style transfer for visual storytelling is the process of identifying a definitive style of a source, such as an artist or culture, and applying the features of that style to a target, such as a character which has a different style. As a proof of concept, the style of the American film director Tim Burton is transferred to a character from Hindu mythology, Yamah. The style transfer is done based on the concept of 'Pattern Language' introduced by Christopher Alexander et al., in his book, 'A Pattern Language'. A set of patterns is developed based on the source and target. The target is then designed based on the patterns. The design is then visualized in a suitable medium.Item The Impact of Extracellular Matrix Stiffness on Angiogensis(2012-12-06) Lee, Po-Feng 1976-Sprouting endothelial cells (ECs) use soluble and insoluble cues to guide migration and expand the existing vascular network to meet changing trophic needs of the tissue during angiogenesis. A noninvasive and non-destructive nonlinear optical microscopy (NLOM) technique was used to optically image endothelial sprouting morphogenesis in three dimensional (3D) collagen matrices with simultaneously captured signals from collagen fibers and endothelial cells using second harmonic generation (SHG) and two-photon excited fluorescence (TPF), respectively. Sprout advancement and lumen expansion companying with ECM alteration were the synergistic results of membrane-associated matrix metalloproteinase and cell traction evidenced by proteinase inhibition and Rho-associated kinase (p160ROCK) inhibition experiments. These physical EC-ECM interactions suggest that ECM mechanical properties may influence angiogenic responses. In a 3D angiogenesis model, we measure angiogenic responses as a function of collagen matrix stiffness by inducing collagen cross-linking with microbial transglutaminase (mTG). Collagen matrices stiffen with both mTG treatment and incubation time as evidenced with biaxial mechanical test results and collagen TPF intensity increases with mTG treatment and that the ratio of TPF/SHG correlates with biaxial tested mechanical stiffness. SHG and optical coherence microscopy (OCM) are further used to show that other physical properties of the matrix do not change with mTG treatment, thus providing the same density but different stiffness with which to measure angiogenic responses. Stiffer matrices promote angiogenesis with more invading sprouts that invade deeper. No differences in lumen size were observed between control and mTG stiffened 3D cultures, but there was evidence of greater matrix remodeling in stiffer gels using NLOM. Results of this study show angiogenic responses are enhanced with increasing stiffness and suggest that these properties may be used in tissue engineering and regenerative medicine applications to engineer angiogenesis.Item Three transdimensional factors for the conversion of 2D acoustic rough surface scattering model results for comparison with 3D scattering(2013-12) Tran, Bryant Minh; Wilson, Preston S.; Isakson, Marcia J.Rough surface scattering is a problem of interest in underwater acoustic remote sensing applications. To model this problem, a fully three-dimensional (3D) finite element model has been developed, but it requires an abundance of time and computational resources. Two-dimensional (2D) models that are much easier to compute are often employed though they don’t natively represent the physical environment. Three quantities have been developed that, when applied, allow 2D rough surface scattering models to be used to predict 3D scattering. The first factor, referred to as the spreading factor, adopted from the work of Sumedh Joshi [1], accounts for geometrical differences between equivalent 2D and 3D model environments. A second factor, referred to as the perturbative factor, is developed through the use of small perturbation theory. This factor is well-suited to account for differences in the scattered field between a 2D model and scattering from an isotropically rough 2D surface in 3D. Lastly, a third composite factor, referred to as the combined factor, of the previous two is developed by taking their minimum. This work deals only with scattering within the plane of the incident wave perpendicular to the scatterer. The applicability of these factors are tested by comparing a 2D scattering model with a fully three-dimensional Monte Carlo finite element method model for a variety of von Karman and Gaussian power spectra. The combined factor shows promise towards a robust method to adequately characterize isotropic 3D rough surfaces using 2D numerical simulations.Item Three-dimensional geoacoustic perturbative inverse technique for the shallow ocean water column(2012-12) Bender, Christopher Matthew; Wilson, Preston S.; Ballard, Megan S.This work focuses on developing an inversion scheme to estimate water-column sound-speed fields in three dimensions. The inversion scheme is based on a linearized perturbative technique which utilizes estimates of modal travel times. The technique is appropriate in the littoral ocean where measurements are made across range and cross-range distances greater than 10 km to ensure sufficient modal dispersion. Previous applications of then inversion technique has been limited to one or two dimensions and/or focused primarily on the seabed. Compared to past applications, the accuracy and uncertainty of the solution is improved by employing approximate equality constraints within the context of \textit{a priori} estimates of model and data covariances. The effectiveness of the constrained technique is explored through a one-dimensional example. The robustness of the technique is illustrated by introducing different types of errors into the inversion and considering the accuracy. A further examination of the technique is given by exploring a three-dimensional example. Several case studies are presented to investigate the effects of different levels of environmental variability and spatial sampling.Item Using 3D/4D CAD modeling for traffic management : development, review, and communication(2012-05) Goyat, Jean; O'Brien, William J.; Machemehl, Randy B.Developing a traffic management plan for a transportation infrastructure project is a complex activity which requires input from many different fields. Ideally, design, construction and traffic engineers all work towards devising an integrated traffic management plan that would consider a variety of aspects. Current literature about traffic management modeling mostly focuses either on high-level tools not adequate to perform required phasing and constructability analysis of construction activities, or study pre- and post-construction conditions. On the other hand, computer aided design (CAD) modeling of infrastructure projects mentions potential benefits for traffic management plan reviewing. However, it does not delve into using 3 dimensional (3D) and 4 dimensional (3D and time) CAD to study (1) the impact of construction activities on traffic, (2) during construction, (3) at a level that allows detailed phasing and constructability reviews for traffic management plan elaboration and communication. Using 3D and 4D CAD modeling can alleviate the complexity of devising traffic management plans for transportation projects by providing an integrated framework from which developers can elaborate, review and communicate their strategies. The many visualization benefits of 3D/4D modeling used in conjunction with their advanced analysis capabilities can tremendously aid compared to more traditional 2D methods. The three transportation projects described in this study aim at illustrating the benefits and added value these models provide to more efficiently and rapidly visualize and analyze intended traffic management strategies, at different stages of the construction process.