Although surveys suggest positive student attitudes toward the use of algorithm animations, it is not clear that they improve learning outcomes. The Graph Algorithm Animation Tool, or Galant, challenges and motivates ...
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Although surveys suggest positive student attitudes toward the use of algorithm animations, it is not clear that they improve learning outcomes. The Graph Algorithm Animation Tool, or Galant, challenges and motivates students to engage more deeply with algorithm concepts, without distracting them with programming language details or GUIs. Even though Galant is specifically designed for graph algorithms, it has also been used to animate other algorithms, most notably sorting algorithms. [ABSTRACT FROM AUTHOR]
In this paper we present an image-based algorithm for surface reconstruction of moving garment from multiple calibrated video cameras. Using a color-coded cloth texture, we reliably match circular features between dif...
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In this paper we present an image-based algorithm for surface reconstruction of moving garment from multiple calibrated video cameras. Using a color-coded cloth texture, we reliably match circular features between different camera views. As surface model we use air a priori known triangle mesh. By identifying the mesh vertices with texture elements we obtain a consistent parameterization of the surface over time without further processing. Missing data points resulting from self-shadowing are plausibly interpolated by minimizing a thin-plate functional. The deforming geometry can be used for different graphics applications, e.g. for realistic retexturing. We show results for real garments demonstrating the accuracy of the recovered flexible shape.
Domain visualization is one of the new research fronts resulted from the proliferation of information visualization, aiming to reveal the essence of a knowledge domain. Information visualization plays an integral role...
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Domain visualization is one of the new research fronts resulted from the proliferation of information visualization, aiming to reveal the essence of a knowledge domain. Information visualization plays an integral role in modeling and representing intellectual structures associated with scientific disciplines. In this article, the domain of computer graphics is visualized based on author cocitation patterns derived from an 18-year span of the prestigious IEEE computer graphics and Applications (1982-1999), This domain visualization utilizes a series of visualization and animation techniques, including author cocitation maps, citation time lines, animation of a high-dimensional specialty space, and institutional profiles. This approach not only augments traditional domain analysis and the understanding of scientific disciplines, but also produces a persistent and shared knowledge space for researchers to keep track the development of knowledge more effectively. The results of the domain visualization are discussed and triangulated in a broader context of the computer graphics field.
We describe an approach to register and merge detailed facade models with a complementary airborne model. The airborne modeling process provides a half-meter resolution model with a bird's-eye view of the entire a...
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We describe an approach to register and merge detailed facade models with a complementary airborne model. The airborne modeling process provides a half-meter resolution model with a bird's-eye view of the entire area, containing terrain profile and building tops. The ground-based modeling process results in a detailed model of the building facades. Using the DSM obtained from airborne laser scans, we localize the acquisition vehicle and register the ground-based facades to the airborne model by means of Monte Carlo localization (MCL). We merge the two models with different resolutions to obtain a 3D model.
In this paper two subset line properties are introduced; the difference concerns the domain of the end points of the line segments under consideration, viz. Q 2 and Z 2 respectively. For both properties, a recursive a...
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In this paper two subset line properties are introduced; the difference concerns the domain of the end points of the line segments under consideration, viz. Q 2 and Z 2 respectively. For both properties, a recursive and a nonrecursive algorithm to generate raster line segments are derived. All algorithms use integer arithmetic only. The accuracy of the algorithms in representing lines will be discussed, as well as their time complexity.
Quartic Beta-splines have third-degree arc-length or geometric continuity at simple knots and are determined by three β or shape parameters. We present a general explicit formula for quartic Beta-splines, and determi...
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Quartic Beta-splines have third-degree arc-length or geometric continuity at simple knots and are determined by three β or shape parameters. We present a general explicit formula for quartic Beta-splines, and determine and illustrate the effects of varying the β parameters on the shape of a quartic Beta-spline curve. We show that quartic (and higher degree) rational Beta-splines with arc-length continuity satisfy the same continuity conditions as (nonrational) Beta-splines. We also show that the torsion continuous spline curves presented by Boehm ("Smooth Curves and Surfaces.” In Geometric Modeling: Algorithms and New Trends, G. E. Farin, Ed. SIAM, Philadelphia, Pa., 1987, pp. 175-184.) are equivalent to nonrational quartic Beta-spline curves, and determine the relationship between the shape parameters for the two types of curves. Finally, we present an algorithm for inserting a new knot and determining the refined control polygon.
This paper presents a software development for the obtaining in an automatic way of three-dimensional models of objects (e.g. sculptures, mechanical pieces). Nowadays, there is available software which is able to crea...
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This paper presents a software development for the obtaining in an automatic way of three-dimensional models of objects (e.g. sculptures, mechanical pieces). Nowadays, there is available software which is able to create three-dimensional models of objects using laser systems, but they are pretty expensive (up to 120,000 Euro) due to the high technology used for data capture (laser scanner). On the other hand, the software depicted in this paper develops a new process that captures the data with a simple digital video camera and a motorized pedestal (about 1200 Euro). This way, more than 1300 images of the object are obtained. The later analysis of the edges of all these images will completely define the geometry of the object. So, this software is able to create accurate digital models with a resolution that varies from hundreds to one million of points. In order to export these three-dimensional models the software generates VRML, or ASCII files. These models are very useful in sciences like computer graphics, architecture, mechanics, automated mapping/facilities management, etc. (c) 2005 Elsevier Ltd. All rights reserved.
New modifications of the Cohen-Sutherland algorithm for clipping lines and line segments in E-2 are presented. The suggested algorithms are based on a technique of coding the line direction together with the end point...
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New modifications of the Cohen-Sutherland algorithm for clipping lines and line segments in E-2 are presented. The suggested algorithms are based on a technique of coding the line direction together with the end points of the clipped line segment. They solve all cases more effectively. The algorithms are convenient for clippings lines or line segments by rectangle. Theoretical considerations and experimental results are also presented.
In the context of using virtual environments (VEs) in Internet-based teleoperation, this paper addresses the issue of parameter acquisition for single-image-based modeling of VEs. By studying the properties of basic t...
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In the context of using virtual environments (VEs) in Internet-based teleoperation, this paper addresses the issue of parameter acquisition for single-image-based modeling of VEs. By studying the properties of basic three-dimensional features such as point sets and edge corners, a parameter-searching method was developed that employs virtual objects as feature-matching templates. This approach is particularly valuable if the environment is subject to unpredictable change.
We present a new technique to display a scene of three-dimensional isothetic parallelepipeds (3D-rectangles), viewed from infinity along one of the coordinate axes (axial view). In this situation, there always exists ...
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We present a new technique to display a scene of three-dimensional isothetic parallelepipeds (3D-rectangles), viewed from infinity along one of the coordinate axes (axial view). In this situation, there always exists a topological sorting of the 3D-rectangles based on the relation of occlusion (a dominance relation). The arising total order is used to generate the axial view, where the two-dimensional view of each 3D-rectangle is incrementally added, starting from the closest 3D-rectangle. The proposed scene-sensitive algorithm runs in time O(N log2N + d log N), where N is the number of 3D-rectangles and d is the number of edges of the display. This improves over the previously best known technique based on the same approach.
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