Capstone provides a software platform with well-abstracted and compact interfaces to create, modify, and query geometry, mesh, and attribution information for a model. This forms a foundation for geometry-based design...
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Capstone provides a software platform with well-abstracted and compact interfaces to create, modify, and query geometry, mesh, and attribution information for a model. This forms a foundation for geometry-based design environments and solvers that can access geometry at runtime for scalable and accurate a-posteriori mesh adaptation.
Texture mapping is an important operation in high-quality computer graphics applications. The principles of image filtering are well established and understood and several high-quality texture filtering algorithms hav...
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Texture mapping is an important operation in high-quality computer graphics applications. The principles of image filtering are well established and understood and several high-quality texture filtering algorithms have been developed. However, these have tended to be either off-line software implementations or based on high-end computer graphics rendering systems. Current generation PC-based graphics acceleration utilises texture pre-filtering techniques based upon an isotropic filter kernel. The most common implementations are those based on MIP-map texture storage and bilinear or trilinear interpolation. Such filters give a reduction in image aliasing at the expense of introducing blurring. As acceleration hardware performance improves, tolerance of such compromises is falling leading to the adoption of "anisotropic" filtering solutions. In this paper we present a detailed description of a low-cost implementation of an anisotropic filtering unit for use within a contemporary graphics pipeline. The filter is shown to produce improved visible results for only a modest increase in hardware cost. (C) 2000 Elsevier Science Ltd. All rights reserved.
Computational photography refers broadly to sensing strategies and algorithmic techniques that enhance or extend the capabilities of digital photography. Although interest in computational photography has steadily inc...
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Computational photography refers broadly to sensing strategies and algorithmic techniques that enhance or extend the capabilities of digital photography. Although interest in computational photography has steadily increased among graphics and vision researchers, progress has been hampered by the lack of a portable, programmable camera platform with enough image quality and computing power to be used for everyday photography. To address this problem, the Stanford computer graphics Laboratory has designed an open architecture for programmable cameras. Our architecture (called Frankencamera) consists of a hardware specification, a software stack based on Linux, and an API (called FCam) with bindings for C++. To demonstrate the viability of this architecture, we've built two reference implementations: a Nokia N900 smartphone with a modified software stack and a custom camera called the Frankencamera F2. Our goal is to standardize the architecture and distribute Frankencameras to researchers and students worldwide, as a step towards creating a community of photographer-programmers who develop algorithms, applications, and hardware for computational cameras.
Several approaches to visualizing simulated data are described. It is noted that a centralized video animation facility represents the state of the art in scientific visualization, but is too expensive to replicate wi...
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Several approaches to visualizing simulated data are described. It is noted that a centralized video animation facility represents the state of the art in scientific visualization, but is too expensive to replicate widely. Methods used at LANL for connecting supercomputers with display units, ranging from dumb terminals to powerful workstations, are also described. Of particular interest is the Scientific Visualization Workbench, an inexpensive and effective way of using `televisualization' to move data from supercomputer to user and to modify the user's display. The implication of higher speed networks are discussed
Evacuation planning is an important and difficult task in building design. The proposed framework can identify optimal evacuation plans using decision points, which control the ratio of agents that select a particular...
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Evacuation planning is an important and difficult task in building design. The proposed framework can identify optimal evacuation plans using decision points, which control the ratio of agents that select a particular route at a specific spatial location. The authors optimize these ratios to achieve the best evacuation based on a quantitatively validated metric for evacuation performance. This metric captures many of the important aspects of an evacuation: total evacuation time, average evacuation time, agent speed, and local agent density. The proposed approach was validated using a night club model that incorporates real data from an actual evacuation. [ABSTRACT FROM AUTHOR]
Occlusion culling and level-of-detail rendering have become two powerful tools for accelerating the handling of very large models in real-time visualization applications. We present a framework that combines both tech...
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Occlusion culling and level-of-detail rendering have become two powerful tools for accelerating the handling of very large models in real-time visualization applications. We present a framework that combines both techniques to improve rendering times. Classical occlusion culling algorithms compute potentially visible sets (PVS), which are supersets of the sets of visible polygons. The novelty of our approach is to estimate the degree of visibility of each object Of the PVS using synthesized coarse occluders. This allows to arrange the objects of each PVS into several Hardly-Visible Sets (HVS) with similar occlusion degree. According to image accuracy and frame rare requirements, HVS provide a way to avoid sending to the graphics pipeline those objects whose pixel contribution is low due to partial occlusion. The image error can be bounded by the user at navigation time. On the other hand, as HVS offer a lighter estimation of the pixel contribution for each scene object, ii can be used for a more convenient selection of the level-of-detail at which objects are rendered. In this paper we describe the new framework technique, provide details of its implementation using a visibility octree as the chosen occlusion culling data structure and show some experimental results on the image quality.
The SurfCuit system integrates circuits into 3D prints by mounting them on the printed surface. SurfCuit does not require tedious circuit casing design or expensive setups, allowing users to build complex, highly cond...
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The SurfCuit system integrates circuits into 3D prints by mounting them on the printed surface. SurfCuit does not require tedious circuit casing design or expensive setups, allowing users to build complex, highly conductive circuit patterns for consumer-level desktop fused decomposition modeling (FDM) 3D printers and thus expediting the process of circuit construction for 3D ***://***/extra/***4 [ABSTRACT FROM AUTHOR]
Three-dimensional results from engineering and scientific computations often involve the display and interpretation of a large volume of complex data. A method is developed for color display of 3D data with several in...
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Three-dimensional results from engineering and scientific computations often involve the display and interpretation of a large volume of complex data. A method is developed for color display of 3D data with several interactive options to facilitate interpretation. The method is based on representing points whose values fall within a specified range as a single hue. An image is formed by overlaying successive 2D frames with increasing hue lightness towards the front. Interactive options to aid interpretations are viewpoint, contour lines, multiple range display, slicing, veiled surfaces, and stereo image pairs. The display method is successfully applied to several types of data. The overall structure and variations of the 3D data are observable, as well as transients which may be overlooked in a large input data set.
Background The FLS training tool box has now been adopted by the Society of Gastrointestinal Endoscopic Surgeons (SAGES) as an official training tool for minimally invasive procedures. Methods To overcome the limitati...
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Background The FLS training tool box has now been adopted by the Society of Gastrointestinal Endoscopic Surgeons (SAGES) as an official training tool for minimally invasive procedures. Methods To overcome the limitations of the physical FLS training tool box, we have developed a Virtual Basic Laparoscopic Skill Trainer (VBLaSTTM) system, which is a 3D simulator that will allow trainees to acquire basic laparoscopic skill. Results The outcome of this work is the development of an integrated visiohaptic workstation environment including force feedback devices and a stereo display interface whereby trainees can practice on virtual versions of the FLS. Realistic graphical rendering and high fidelity haptic interactions are achieved. Conclusions Surgical skill training is a long and tedious process of acquiring fine motor skills. It is expected that residents would start on trainers such as VBLaSTTM and after reaching a certain level of competence would progress to the more complex trainers for training on specific surgical procedures. Copyright (c) 2008 John Wiley & Sons, Ltd.
A three-dimensional scan-conversion algorithm , that scan-converts 3D planar polygons into their discrete voxel-map representation within a Cubic Frame Buffer ( CFB ), is presented. The algorithm, which is a variation...
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A three-dimensional scan-conversion algorithm , that scan-converts 3D planar polygons into their discrete voxel-map representation within a Cubic Frame Buffer ( CFB ), is presented. The algorithm, which is a variation of a conventional 2D scan-line filling algorithm, is incremental and uses only simple operations like additions and tests inside the inner loops. The algorithm performs scan-conversion with computational complexity which is linear in the number of voxels written to the CFB. Another algorithm that scan-converts polygons clipped to the CFB boundaries with no added time complexity is also presented. Furthermore, an all-integer decision mechanism which makes the inner-most loop of the algorithm more efficient is discussed too. All the algorithms guarantee lack of 6-connected “tunnels” in the converted polygons. The algorithms have been implemented as part of the 3D geometry processor of the CUBE Architecture , which is a voxel-based system for 3D graphics. These algorithms allow the CUBE system to generate a discrete voxel representation of the essential 3D polygon primitive, enabling CUBE to also cater to applications generating synthetic images.
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