Visualization of particle traces provides intuitive and efficient means for the exploration and analysis of complex vector fields. The paper presents a method suitable for the real-time visualization of arbitrarily la...
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ISBN:
(纸本)0780372239
Visualization of particle traces provides intuitive and efficient means for the exploration and analysis of complex vector fields. The paper presents a method suitable for the real-time visualization of arbitrarily large time-varying vector fields in virtual environments. We describe an out-of-core scheme in which two distinct pre-processing and rendering components enable real-time data streaming and visualization. The presented approach yields low-latency application start-up times and small memory footprints. The described system was used to implement a "volumetric fog lance," which can emit up to 60000 particles into a flow field while maintaining an interactive frame rate of 60 frames per second. All algorithms were specifically designed to support commodity hardware. The proof-of-concept system is running on a low-cost Linux workstation equipped with a 120 GB E-IDE RAID (redundant array of inexpensive disk) system.
Automatic character recognition and image understanding of a given paper document are the main objectives of the computer vision field. For these problems, a basic step is to isolate characters and group words from th...
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Existing methods of morphing 3D meshes are often limited to cases in which 3D input meshes to be morphed are topologically equivalent. The paper presents a new method for morphing 3D meshes having different surface to...
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Existing methods of morphing 3D meshes are often limited to cases in which 3D input meshes to be morphed are topologically equivalent. The paper presents a new method for morphing 3D meshes having different surface topological types. The most significant feature of the method is that it allows explicit control of topological transitions that occur during the morph. Transitions of topological types are specified by means of a compact formalism that resulted from a rigorous examination of singularities of 4D hypersurfaces and embeddings of meshes in 3D space. Using the formalism, every plausible path of topological transitions can be classified into a small set of cases. In order to guide a topological transition during the morph, our method employs a key frame that binds two distinct surface topological types. The key frame consists of a pair of "faces", each of which is homeomorphic to one of the source (input) 3D meshes. Interpolating the source meshes and the key frame by using a tetrahedral 4D mesh and then intersecting the interpolating mesh with another 4D hypersurface creates a morphed 3D mesh. We demonstrate the power of our methodology by using several examples of topology transcending morphing.
We propose a new routing graph, the Restricted Delaunay Graph (RDG), for ad hoc networks. Combined with a node clustering algorithm, RDG can be used as an underlying graph for geographic routing protocols. This graph ...
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ISBN:
(纸本)1581134282
We propose a new routing graph, the Restricted Delaunay Graph (RDG), for ad hoc networks. Combined with a node clustering algorithm, RDG can be used as an underlying graph for geographic routing protocols. This graph has the following attractive properties: (1) it is a planar graph;(2) between any two nodes there exists a path in the RDG whose length, whether measure in terms of topological or Euclidean distance, is only a constant times the optimum length possible;and (3) the graph can be maintained efficiently in a distributed manner when the nodes move around. Furthermore, each node only needs constant time to make routing decisions. We also show by simulation that the RDG outperforms the previously proposed routing graphs under the Greedy Perimeter Stateless Routing (GPSR) protocol. In addition, we investigate theoretical bounds on the quality of paths discovered using GPSR.
Professor John Belcher developed a series of short videos with animation and text of selected experiments to properly demonstrate the phenomena of electromagnetism. Such 3D animations are visually compelling, instilli...
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Professor John Belcher developed a series of short videos with animation and text of selected experiments to properly demonstrate the phenomena of electromagnetism. Such 3D animations are visually compelling, instilling in the student both a sense of wonder about the phenomena and a mental model of why and how it works. The products of these approach includes video clips of demonstrations, 3D animations of these demonstration which display time changing field-lines as a guide to understanding their dynamical effects and Java applets which allow the student to actively construct and animate 2D field lines for varying configurations of sources. These technologies are also implemented to develop animations for Faraday's insights, using video clips.
Most systems that support visual interaction with 3D models use shape representations based on triangle meshes. Thesize of these representations imposes limits on applications for which complex 3D models must be acces...
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Most systems that support visual interaction with 3D models use shape representations based on triangle meshes. The
size of these representations imposes limits on applications for which complex 3D models must be accessed remotely. Techniques for
simplifying and compressing 3D models reduce the transmission time. Multiresolution formats provide quick access to a crude model
and then refine it progressively. Unfortunately, compared to the best nonprogressive compression methods, previously proposed
progressive refinement techniques impose a significant overhead when the full resolution model must be downloaded. The CPM
(Compressed Progressive Meshes) approach proposed here eliminates this overhead. It uses a new technique, which refines the
topology of the mesh in batches, which each increase the number of vertices by up to 50 percent. Less than an amortized total of 4 bits
per triangle encode where and how the topological refinements should be applied. We estimate the position of new vertices from the
positions of their topological neighbors in the less refined mesh using a new estimator that leads to representations of vertex
coordinates that are 50 percent more compact than previously reported progressive geometry compression techniques.
Let A and B be two convex polytopes in R3 with m and n facets, respectively. The penetration depth of A and B, denoted as π(A, B), is the minimum distance by which A has to be translated so that A and B do not inters...
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Realistic animation of soft objects such as cloth is essential for plausible character animation. Many techniques have been proposed for the simulation of soft objects, and most of them are based on numerical integrat...
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Realistic animation of soft objects such as cloth is essential for plausible character animation. Many techniques have been proposed for the simulation of soft objects, and most of them are based on numerical integration. Among the techniques, the implicit integration method is the most likely technique for real time environments, since it allows large time steps for cloth simulation by ensuring the stability of systems. However the most critical flaw of the implicit method is that it involves a large linear system. The paper presents a fast animation technique for animating soft objects based on a mass-spring model with an approximated implicit method which does not involve linear system solving. The proposed technique stably updates the state of n mass-points in O(n) time when the number of total springs are O(n). Because the mass-spring model shows a superelastic effect, the excessively deformed springs (i.e., super-elongated springs) should be adjusted for reality. The paper presents an efficient inverse dynamics process to adjust the super-elongated springs.
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