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220
Edgebreaker: Connectivity compression for triangle meshes
 IEEE Transactions on Visualization and Computer Graphics
, 1999
"... Edgebreaker is a simple scheme for compressing the triangle/vertex incidence graphs (sometimes called connectivity or topology) of threedimensional triangle meshes. Edgebreaker improves upon the worst case storage required by previously reported schemes, most of which require O(nlogn) bits to store ..."
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Cited by 277 (24 self)
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Edgebreaker is a simple scheme for compressing the triangle/vertex incidence graphs (sometimes called connectivity or topology) of threedimensional triangle meshes. Edgebreaker improves upon the worst case storage required by previously reported schemes, most of which require O(nlogn) bits to store the incidence graph of a mesh of n triangles. Edgebreaker requires only 2n bits or less for simple meshes and can also support fully general meshes by using additional storage per handle and hole. Edgebreaker’s compression and decompression processes perform the same traversal of the mesh from one triangle to an adjacent one. At each stage, compression produces an opcode describing the topological relation between the current triangle and the boundary of the remaining part of the mesh. Decompression uses these opcodes to reconstruct the entire incidence graph. Because Edgebreaker’s compression and decompression are independent of the vertex locations, they may be combined with a variety of vertexcompressing techniques that exploit topological information about the mesh to better estimate vertex locations. Edgebreaker may be used to compress the connectivity of an entire mesh bounding a 3D polyhedron or the connectivity of a triangulated surface patch whose boundary needs not be encoded. Its superior compression capabilities, the simplicity of its implementation, and its versatility make Edgebreaker particularly suitable for the emerging 3D data exchange standards for interactive graphic applications. The paper also offers a comparative survey of the rapidly growing field of geometric compression.
Geometric Compression through Topological Surgery
 ACM TRANSACTIONS ON GRAPHICS
, 1998
"... ... this article introduces a new compressed representation for complex triangulated models and simple, yet efficient, compression and decompression algorithms. In this scheme, vertex positions are quantized within the desired accuracy, a vertex spanning tree is used to predict the position of each ..."
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Cited by 258 (28 self)
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... this article introduces a new compressed representation for complex triangulated models and simple, yet efficient, compression and decompression algorithms. In this scheme, vertex positions are quantized within the desired accuracy, a vertex spanning tree is used to predict the position of each vertex from 2, 3, or 4 of its ancestors in the tree, and the correction vectors are entropy encoded. Properties, such as normals, colors, and texture coordinates, are compressed in a similar manner. The connectivity is encoded with no loss of information to an average of less than two bits per triangle. The vertex spanning tree and a small set of jump edges are used to split the model into a simple polygon. A triangle spanning tree and a sequence of marching bits are used to encode the triangulation of the polygon. Our approach improves on Michael Deering's pioneering results by exploiting the geometric coherence of several ancestors in the vertex spanning tree, preserving the connectivity with no loss of information, avoiding vertex repetitions, and using about three times fewer bits for the connectivity. However, since decompression requires random access to all vertices, this method must be modified for hardware rendering with limited onboard memory. Finally, we demonstrate implementation results for a variety of VRML models with up to two orders of magnitude compression
Hierarchical Image Caching for Accelerated Walkthroughs of Complex Environments
, 1996
"... We present a new method that utilizes path coherence to accelerate walkthroughs of geometrically complex static scenes. As a preprocessing step, our method constructs a BSPtree that hierarchically partitions the geometric primitives in the scene. In the course of a walkthrough, images of nodes at v ..."
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Cited by 169 (10 self)
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We present a new method that utilizes path coherence to accelerate walkthroughs of geometrically complex static scenes. As a preprocessing step, our method constructs a BSPtree that hierarchically partitions the geometric primitives in the scene. In the course of a walkthrough, images of nodes at various levels of the hierarchy are cached for reuse in subsequent frames. A cached image is reused by texturemapping it onto a single quadrilateral that is drawn instead of the geometry contained in the corresponding node. Visual artifacts are kept under control by using an error metric that quantifies the discrepancy between the appearance of the geometry contained in a node and the cached image. The new method is shown to achieve speedups of an order of magnitude for walkthroughs of a complex outdoor scene, with little or no loss in rendering quality. CR Categories and Subject Descriptors: I.3.3 [Computer Graphics ]: Picture/Image Generation  Display algorithms; I.3.7 [Computer Graphi...
Fast Calculation of Soft Shadow Textures Using Convolution
, 1998
"... The calculation of detailed shadows remains one of the most difficult challenges in computer graphics, especially in the case of extended (linear or area) light sources. This paper introduces a new tool for the calculation of shadows cast by extended light sources. Exact shadows are computed in some ..."
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Cited by 109 (6 self)
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The calculation of detailed shadows remains one of the most difficult challenges in computer graphics, especially in the case of extended (linear or area) light sources. This paper introduces a new tool for the calculation of shadows cast by extended light sources. Exact shadows are computed in some constrained configurations by using a convolution technique, yielding a fast and accurate solution. Approximate shadows can be computed for general configurations by applying the convolution to a representative "ideal" configuration. We analyze the various sources of approximation in the process and derive a hierarchical, errordriven algorithm for fast shadow calculation in arbitrary configurations using a hierarchy of object clusters. The convolution is performed on images rendered in an offscreen buffer and produces a shadow map used as a texture to modulate the unoccluded illumination. Light sources can have any 3D shape as well as arbitrary emission characteristics, while shadow maps can be applied to groups of objects at once. The method can be employed in a hierarchical radiosity system, or directly as a shadowing technique. We demonstrate results for various scenes, showing that soft shadows can be generated at interactive rates for dynamic environments.
Interactive technical illustration
 In Proceedings of the 1999 symposium on Interactive 3D graphics
, 1999
"... A rendering is an abstraction that favors, preserves, or even emphasizes some qualities while sacrificing, suppressing, or omitting other characteristics that are not the focus of attention. Most computer graphics rendering activities have been concerned with photorealism, i.e., trying to emulate an ..."
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Cited by 107 (8 self)
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A rendering is an abstraction that favors, preserves, or even emphasizes some qualities while sacrificing, suppressing, or omitting other characteristics that are not the focus of attention. Most computer graphics rendering activities have been concerned with photorealism, i.e., trying to emulate an image that looks like a highquality photograph. This laudable goal is useful and appropriate in many applications, but not in technical illustration where elucidation of structure and technical information is the preeminent motivation. This calls for a different kind of abstraction in which technical communication is central, but art and appearance are still essential instruments toward this end. Work that has been done on computer generated technical illustrations has focused on static images, and has not included all of the techniques used to hand draw technical illustrations. A paradigm for the display of technical illustrations in a dynamic environment is presented. This display environment includes all of the benefits of computer generated technical illustrations, such as a clearer picture of shape, structure, and material composition than traditional computer graphics methods. It also includes the threedimensional interactive strength of modem display systems. This is accomplished by using new algorithms for real time drawing of silhouette curves, algorithms which solve a number of the problems inherent in previous methods. We incorporate current nonphotorealistic lighting methods, and augment them with new shadowing algorithms based on accepted techniques used by artists and studies carried out in human perception. This paper, all of the images, and a mpeg video clip are available at
Fast matrix multiplies using graphics hardware
, 2001
"... We present a technique for large matrixmatrix multiplies using low cost graphics hardware. The result is computed by literally visualizing the computations of a simple parallel processing algorithm. Current graphics hardware technology has limited precision and thus limits immediate applicability o ..."
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Cited by 105 (0 self)
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We present a technique for large matrixmatrix multiplies using low cost graphics hardware. The result is computed by literally visualizing the computations of a simple parallel processing algorithm. Current graphics hardware technology has limited precision and thus limits immediate applicability of our algorithm. We include results demonstrating proof of concept, correctness, speedup, and a simple application. This is therefore forward looking research: a technique ready for technology on the horizon.
An annotation language for optimizing software libraries
 In Second Conference on Domain Specific Languages
, 1999
"... Rights to individual papers remain with the author or the author's employer. Permission is granted for noncommercial reproduction of the work for educational or research purposes. This copyright notice must be included in the reproduced paper. USENIX acknowledges all trademarks herein. ..."
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Cited by 93 (15 self)
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Rights to individual papers remain with the author or the author's employer. Permission is granted for noncommercial reproduction of the work for educational or research purposes. This copyright notice must be included in the reproduced paper. USENIX acknowledges all trademarks herein.
The design and implementation of an objectoriented toolkit for 3d graphics and visualization
 IEEE Visualization
, 1996
"... The Visualization Toolkit (vtk) is a freely available C++ class library for 3D graphics and visualization. In this paper we describe core characteristics of the toolkit. This includes a description of objectoriented models for graphics and visualization; methods for synchronizing system execution; ..."
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Cited by 85 (0 self)
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The Visualization Toolkit (vtk) is a freely available C++ class library for 3D graphics and visualization. In this paper we describe core characteristics of the toolkit. This includes a description of objectoriented models for graphics and visualization; methods for synchronizing system execution; a summary of data representation schemes; the role of C++; issues in portability across PC and Unix systems; and how we automatically wrap the C++ class library with interpreted languages such as Java and Tcl. We also demonstrate the capabilities of the system for scalar, vector, tensor, and other visualization
Optimization of Mesh Locality for Transparent Vertex Caching
"... Bus traffic between the graphics subsystem and memory can become a bottleneck when rendering geometrically complex meshes. In this paper, we investigate the use of vertex caching to transparently reduce geometry bandwidth. Use of an indexed triangle strip representation permits application programs ..."
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Cited by 74 (0 self)
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Bus traffic between the graphics subsystem and memory can become a bottleneck when rendering geometrically complex meshes. In this paper, we investigate the use of vertex caching to transparently reduce geometry bandwidth. Use of an indexed triangle strip representation permits application programs to animate the meshes at video rates, and provides backward compatibility on legacy hardware. The efficiency of vertex caching is maximized by reordering the faces in the mesh during a preprocess. We present two reordering techniques, a fast greedy stripgrowing algorithm and a local optimization algorithm. The stripgrowing algorithm performs lookahead simulations of the cache to adapt strip lengths to the cache capacity. The local optimization algorithm improves this initial result by exploring a set of perturbations to the face ordering. The resulting cache miss rates are comparable to the efficiency of the earlier mesh buffer scheme described by Deering and Chow, even though the vertex cache is not actively managed.