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94
G.: The ball-pivoting algorithm for surface reconstruction
- IEEE Transactions on Visualization and Computer Graphics
, 1999
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Computing Contour Trees in All Dimensions
, 1999
"... We show that contour trees can be computed in all dimensions by a simple algorithm that merges two trees. Our algorithm extends, simplifies, and improves work of Tarasov and Vyalyi and of van Kreveld et al. ..."
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Cited by 159 (11 self)
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We show that contour trees can be computed in all dimensions by a simple algorithm that merges two trees. Our algorithm extends, simplifies, and improves work of Tarasov and Vyalyi and of van Kreveld et al.
Out-of-Core Simplification of Large Polygonal Models
, 2000
"... We present an algorithm for out-of-core simplification of large polygonal datasets that are too complex to fit in main memory. The algorithm extends the vertex clustering scheme of Rossignac and Borrel [13] by using error quadric information for the placement of each cluster's representative ve ..."
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Cited by 159 (10 self)
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We present an algorithm for out-of-core simplification of large polygonal datasets that are too complex to fit in main memory. The algorithm extends the vertex clustering scheme of Rossignac and Borrel [13] by using error quadric information for the placement of each cluster's representative vertex, which better preserves fine details and results in a low mean geometric error. The use of quadrics instead of the vertex grading approach in [13] has the additional benefits of requiring less disk space and only a single pass over the model rather than two. The resulting linear time algorithm allows simplification of datasets of arbitrary complexity. In order
VisTrails: Enabling interactive multiple-view visualizations
- In IEEE Visualization 2005
, 2005
"... Figure 1: VisTrails Visualization Spreadsheet. This ensemble shows the surface salinity variation at the mouth of the Columbia River over the period of a day. The green regions represent the fresh-water discharge of the river into the ocean. A single vistrail specification is used to construct this ..."
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Cited by 111 (28 self)
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Figure 1: VisTrails Visualization Spreadsheet. This ensemble shows the surface salinity variation at the mouth of the Columbia River over the period of a day. The green regions represent the fresh-water discharge of the river into the ocean. A single vistrail specification is used to construct this ensemble. Each cell corresponds to an instance of this specification executed using a different timestamp value. VisTrails is a new system that enables interactive multiple-view visualizations by simplifying the creation and maintenance of visualization pipelines, and by optimizing their execution. It provides a general infrastructure that can be combined with existing visualization systems and libraries. A key component of VisTrails is the visualization trail (vistrail), a formal specification of a pipeline. Unlike existing dataflow-based systems, in VisTrails there is a clear separation between the specification of a pipeline and its execution instances. This separation enables powerful scripting capabilities and provides a scalable mechanism for generating a large number of visualizations. VisTrails also leverages the vistrail specification to identify and avoid redundant operations. This optimization is especially useful while exploring multiple visualizations. When variations of the same pipeline need to be executed, substantial speedups can be obtained by caching the results of overlapping subsequences of the pipelines. In this paper, we describe the design and implementation of VisTrails, and show its effectiveness in different application scenarios.
M.: Real-time ray-casting and advanced shading of discrete isosurfaces
- Computer Graphics Forum
"... Figure 1: We render high-quality implicit surfaces on regular grids, e.g., distance fields or medical CT scans, in real-time without pre-computing additional per-voxel information. Gradients with C1 continuity, second-order derivatives, and surface curvature are computed exactly for each output pixe ..."
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Cited by 84 (12 self)
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Figure 1: We render high-quality implicit surfaces on regular grids, e.g., distance fields or medical CT scans, in real-time without pre-computing additional per-voxel information. Gradients with C1 continuity, second-order derivatives, and surface curvature are computed exactly for each output pixel using tri-cubic filtering. Applications include surface interrogation and visualizing levelset computations by color mapping curvature measures (center), and ridge and valley lines (left and right). This paper presents a real-time rendering pipeline for implicit surfaces defined by a regular volumetric grid of samples. We use a ray-casting approach on current graphics hardware to perform a direct rendering of the isosurface. A two-level hierarchical representation of the regular grid is employed to allow object-order and image-order empty space skipping and circumvent memory limitations of graphics hardware. Adaptive sampling and iterative refinement lead to high-quality ray/surface intersections. All shading operations are deferred to image space, making their computational effort independent of the size of the input data. A continuous third-order reconstruction filter allows on-the-fly evaluation of smooth normals and extrinsic curvatures at any point on the surface without interpolating data computed at grid points. With these local shape descriptors, it is possible to perform advanced shading using high-quality lighting and non-photorealistic effects in real-time.
External Memory Data Structures
, 2001
"... In many massive dataset applications the data must be stored in space and query efficient data structures on external storage devices. Often the data needs to be changed dynamically. In this chapter we discuss recent advances in the development of provably worst-case efficient external memory dynami ..."
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Cited by 76 (32 self)
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In many massive dataset applications the data must be stored in space and query efficient data structures on external storage devices. Often the data needs to be changed dynamically. In this chapter we discuss recent advances in the development of provably worst-case efficient external memory dynamic data structures. We also briefly discuss some of the most popular external data structures used in practice.
Out-of-core algorithms for scientific visualization and computer graphics
- In Visualization’02 Course Notes
, 2002
"... Recently, several external memory techniques have been developed for a wide variety of graphics and visualization problems, including surface simplification, volume rendering, isosurface generation, ray tracing, surface reconstruction, and so on. This work has had significant impact given that in re ..."
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Cited by 59 (11 self)
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Recently, several external memory techniques have been developed for a wide variety of graphics and visualization problems, including surface simplification, volume rendering, isosurface generation, ray tracing, surface reconstruction, and so on. This work has had significant impact given that in recent years there has been a rapid increase in the raw size of datasets. Several technological trends are contributing to this, such as the development of high-resolution 3D scanners, and the need to visualize ASCI-size (Accelerated Strategic Computing Initiative) datasets. Another important push for this kind of technology is the growing speed gap between main memory and caches, which penalizes algorithms that do not optimize for coherence of access. Because of these reasons, much research in computer graphics focuses on developing out-of-core (and often cache-friendly) techniques. This paper surveys fundamental issues, current problems, and unresolved questions, and aims to provide graphics researchers and professionals with an effective knowledge of current techniques, as well as the foundation to develop novel techniques on their own. Keywords: Out-of-core algorithms, scientific visualization, computer graphics, interactive rendering, vol-ume rendering, surface simplification.
A Memory Insensitive Technique for Large Model Simplification
"... In this paper we propose three simple, but significant improvements to the OoCS (Out-of-Core Simplification) algorithm of Lindstrom [20] which increase the quality of approximations and extend the applicability of the algorithm to an even larger class of compute systems. The original OoCS algorithm ..."
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Cited by 55 (11 self)
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In this paper we propose three simple, but significant improvements to the OoCS (Out-of-Core Simplification) algorithm of Lindstrom [20] which increase the quality of approximations and extend the applicability of the algorithm to an even larger class of compute systems. The original OoCS algorithm has memory complexity that depends on the size of the output mesh, but no dependency on the size of the input mesh. That is, it can be used to simplify meshes of arbitrarily large size, but the complexity of the output mesh is limited by the amount of memory available. Our first contribution is a version of OoCS that removes the dependency of having enough memory to hold (even) the simplified mesh. With our new algorithm, the whole process is made essentially independent of the available memory on the host computer. Our new technique uses disk instead of main memory, but it is carefully designed to avoid costly random accesses. Our two other contributions improve the quality of the approximations generated by OoCS. We propose a scheme for preserving surface boundaries which does not use connectivity information, and a scheme for constraining the position of the “representative vertex” of a grid cell to an optimal position inside the cell.
Isosurface Extraction in Time-varying Fields Using a Temporal Branch-on-Need Tree (T-BON)
- IEEE Transactions on Visualization and Computer Graphics
, 1999
"... The Temporal Branch-on-Need Tree (T-BON) extends the threedimensional branch-on-need octree for time-varying isosurface extraction. At each time step, only those portions of the tree and data necessary to construct the current isosurface are read from disk. This algorithm can thus exploit the tempor ..."
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Cited by 54 (1 self)
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The Temporal Branch-on-Need Tree (T-BON) extends the threedimensional branch-on-need octree for time-varying isosurface extraction. At each time step, only those portions of the tree and data necessary to construct the current isosurface are read from disk. This algorithm can thus exploit the temporal locality of the isosurface and, as a geometric technique, spatial locality between cells in order to improve performance. Experimental results demonstrate the performance gained and memory overhead saved using this technique. Keywords: isosurface, time-dependent scalar field visualization, multiresolution methods, octree 1 Introduction Isosurface extraction is an important technique for visualizing volumetric data. By exposing contours of constant value, isosurfaces provide a mechanism for understanding the structure of a scalar field. This method has been used effectively in several disciplines, including medicine [12, 18], computational fluid dynamics (CFD) [6, 7], and molecular dynam...
External memory view-dependent simplification
- IN PROCEEDINGS EUROGRAPHICS (2000
, 2004
"... In this paper, we propose a novel external-memory algorithm to support view-dependent simplification for datasets much larger than main memory. In the preprocessing phase, we use a new spanned sub-meshes simplification technique to build view-dependence trees I/O-efficiently, which preserves the cor ..."
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Cited by 52 (5 self)
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In this paper, we propose a novel external-memory algorithm to support view-dependent simplification for datasets much larger than main memory. In the preprocessing phase, we use a new spanned sub-meshes simplification technique to build view-dependence trees I/O-efficiently, which preserves the correct edge collapsing order and thus assures the run-time image quality. We further process the resulting view-dependence trees to build the meta-node trees, which can facilitate the run-time level-of-detail rendering and is kept in disk. During run-time navigation, we keep in main memory only the portions of the meta-node trees that are necessary to render the current level of details, plus some prefetched portions that are likely to be needed in the near future. The prefetching prediction takes advantage of the nature of the run-time traversal of the meta-node trees, and is both simple and accurate. We also employ the implicit dependencies for preventing incorrect foldovers, as well as main-memory buffer management and parallel processes scheme to separate the disk accesses from the navigation operations, all in an integrated manner. The experiments show that our approach scales well with respect to the main memory size available, with encouraging preprocessing and run-time rendering speeds and without sacrificing the image quality.
