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24
Interactive view-dependent rendering of large isosurfaces
- In: Proceedings of visualization ’02
, 2002
"... Figure 1: Closeup view of an isosurface feature in the mixing interface of two gases showing the texture mapped surface, underlying triangle mesh, and the adaptively refined tetrahedral mesh around the region of interest. Time step = 273, Isovalue = 206, Isosurface error = 1.5, 50K Triangles, render ..."
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Cited by 54 (10 self)
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Figure 1: Closeup view of an isosurface feature in the mixing interface of two gases showing the texture mapped surface, underlying triangle mesh, and the adaptively refined tetrahedral mesh around the region of interest. Time step = 273, Isovalue = 206, Isosurface error = 1.5, 50K Triangles, rendered at 7 frames per second. We present an algorithm for interactively extracting and rendering isosurfaces of large volume datasets in a view-dependent fashion. A recursive tetrahedral mesh refinement scheme, based on longest edge bisection, is used to hierarchically decompose the data into a multiresolution structure. This data structure allows fast extraction of arbitrary isosurfaces to within user specified view-dependent er-ror bounds. A data layout scheme based on hierarchical space fill-ing curves provides access to the data in a cache coherent manner that follows the data access pattern indicated by the mesh refine-ment.
Line drawings from volume data
- ACM Trans. Graph
, 2005
"... classroom use is granted without fee provided that copies are not made or distributed for commercial advantage and that copies bear this notice and the full citation on the first page. Copyrights for components of this work owned by others than ACM must be honored. Abstracting with credit is permitt ..."
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Cited by 41 (2 self)
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classroom use is granted without fee provided that copies are not made or distributed for commercial advantage and that copies bear this notice and the full citation on the first page. Copyrights for components of this work owned by others than ACM must be honored. Abstracting with credit is permitted. To copy otherwise, to republish, to post on servers, or to redistribute to lists, requires prior specific permission and/or a fee. Request permissions from Permissions
A.: Visibility Culling Using Plenoptic Opacity Functions for Large Data Visualization
- In Proceedings of IEEE Visualization ’03 (2003
, 2003
"... Visibility culling has the potential to accelerate large data visualization in significant ways. Unfortunately, existing algorithms do not scale well when parallelized, and require full re-computation whenever the opacity transfer function is modified. To address these issues, we have designed a Ple ..."
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Cited by 25 (11 self)
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Visibility culling has the potential to accelerate large data visualization in significant ways. Unfortunately, existing algorithms do not scale well when parallelized, and require full re-computation whenever the opacity transfer function is modified. To address these issues, we have designed a Plenoptic Opacity Function (POF) scheme to encode the view-dependent opacity of a volume block. POFs are computed off-line during a pre-processing stage, only once for each block. We show that using POFs is (i) an efficient, conservative and effective way to encode the opacity variations of a volume block for a range of views, (ii) flexible for re-use by a family of opacity transfer functions without the need for additional off-line processing, and (iii) highly scalable for use in massively parallel implementations. Our results confirm the efficacy of POFs for visibility culling in large-scale parallel volume rendering; we can interactively render the Visible Woman dataset using software ray-casting on 32 processors, with interactive modification of the opacity transfer function on-the-fly.
Distributed Data Management for Large Volume Visualization
- In Proceedings of IEEE Visualization 2005
, 2005
"... We propose a distributed data management scheme for large data visualization that emphasizes efcient data sharing and access. To minimize data access time and support users with a variety of lo-cal computing capabilities, we introduce an adaptive data selection method based on an Enhanced Time-Space ..."
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Cited by 21 (3 self)
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We propose a distributed data management scheme for large data visualization that emphasizes efcient data sharing and access. To minimize data access time and support users with a variety of lo-cal computing capabilities, we introduce an adaptive data selection method based on an Enhanced Time-Space Partitioning (ETSP) tree that assists with effective visibility culling, as well as multires-olution data selection. By traversing the tree, our data management algorithm can quickly identify the visible regions of data, and, for each region, adaptively choose the lowest resolution satisfying user-specied error tolerances. Only necessary data elements are ac-cessed and sent to the visualization pipeline. To further address the issue of sharing large-scale data among geographically distributed collaborative teams, we have designed an infrastructure for integrat-ing our data management technique with a distributed data storage system provided by Logistical Networking (LoN). Data sets at dif-ferent resolutions are generated and uploaded to LoN for wide-area access. We describe a parallel volume rendering system that veries the effectiveness of our data storage, selection and access scheme.
Interactive Isosurface Ray Tracing of Large Octree Volumes
- In Proceedings of the 2006 IEEE Symposium on Interactive Ray Tracing
, 2006
"... Figure 1: Large volume data ray-traced at 512 2 using octrees for compression and acceleration. From left to right: (1) LLNL Richtmyer-Meshkov instability field (shown at timestep 270, with an isovalue of 100). (2) Closer view of the previous scene. (3) Utah CSAFE heptane simulation (timestep 152, i ..."
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Cited by 18 (9 self)
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Figure 1: Large volume data ray-traced at 512 2 using octrees for compression and acceleration. From left to right: (1) LLNL Richtmyer-Meshkov instability field (shown at timestep 270, with an isovalue of 100). (2) Closer view of the previous scene. (3) Utah CSAFE heptane simulation (timestep 152, isovalue 42). Data is losslessly compressed into an octree volume to occupy less than one quarter the size of the original 3D array. Our approach permits storage of large data such as the LLNL simulation, and full sequences of medium-size data such as the heptane, in main memory of consumer machines. Frame rates on an Intel Core Duo 2.16 GHz laptop with 2 GB RAM are 2.4, 1.3, and 3.3 fps respectively. On a 16-node NUMA 2.4 GHz Opteron workstation, these images render at 17.9, 9.8, and 22.0 fps. We present a technique for ray tracing isosurfaces of large compressed structured volumes. Data is first converted into a losslesscompression octree representation that occupies a fraction of the original memory footprint. An isosurface is then dynamically rendered by tracing rays through a min/max hierarchy inside interior octree nodes. By embedding the acceleration tree and scalar data in a single structure and employing optimized octree hash schemes, we achieve competitive frame rates on common multicore architectures, and render large time-variant data that could not otherwise be accomodated.
Coherent Multiresolution Isosurface Ray Tracing
, 2007
"... We implement and evaluate a fast ray tracing method for rendering large structured volumes. Input data is compressed into an octree, enabling residency in CPU main memory. We cast packets of coherent rays through a min/max acceleration structure within the octree, employing a slice-based technique ..."
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Cited by 16 (8 self)
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We implement and evaluate a fast ray tracing method for rendering large structured volumes. Input data is compressed into an octree, enabling residency in CPU main memory. We cast packets of coherent rays through a min/max acceleration structure within the octree, employing a slice-based technique to amortize the higher cost of compressed data access. By employing a multiresolution level of detail scheme in conjunction with packets, coherent ray tracing can efficiently render inherently incoherent scenes of complex data. We achieve higher performance with lesser footprint than previous isosurface ray tracers, and deliver large frame buffers, smooth gradient normals and shadows at relatively lesser cost. In this context, we weigh the strengths of coherent ray tracing against those of the conventional single-ray approach.
SOLTESZ S.: Remote visualization by browsing image based databases with logistical networking
- In ProceedingsofSupercomputing
, 2003
"... The need to provide remote visualization of large datasets with adequate levels of quality and interactivity has become a major impediment to distributed collaboration in Computational Science. Although Image Based Rendering (IBR) techniques based on plenoptic functions have some important advantage ..."
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Cited by 16 (9 self)
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The need to provide remote visualization of large datasets with adequate levels of quality and interactivity has become a major impediment to distributed collaboration in Computational Science. Although Image Based Rendering (IBR) techniques based on plenoptic functions have some important advantages over other approaches to this problem, they suffer from an inability to deal with issues of network latency and server load, due to the large size of the IBR databases they generate. Consequently, IBR techniques have been left largely unexplored for this purpose. In this paper we describe strategies for addressing these obstacles using Logistical Networking (LoN), which is a new and highly scalable approach to deploying storage as a shared communication resource. Leveraging LoN technology and infrastructure, we developed a remote visualization system based on concepts of light field rendering, an IBR method using a 4-D plenoptic function. Our system extends existing work on light fields by employing a modified method of parameterization and data organization that supports more efficient prefetching, caching and loss-less compression. Using this approach, we have been able to interactively browse multi-gigabyte, high-resolution light field databases across the wide area network at 30 frames per second. 1.
Visibility culling for timevarying volume rendering using temporal occlusion coherence
- In VIS ’04: Proceedings of the conference on Visualization ’04
, 2004
"... Typically there is a high coherence in data values between neighboring time steps in an iterative scientific software simulation; this characteristic similarly contributes to a corresponding coherence in the visibility of volume blocks when these consecutive time steps are rendered. Yet traditional ..."
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Cited by 10 (2 self)
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Typically there is a high coherence in data values between neighboring time steps in an iterative scientific software simulation; this characteristic similarly contributes to a corresponding coherence in the visibility of volume blocks when these consecutive time steps are rendered. Yet traditional visibility culling algorithms were mainly designed for static data, without consideration of such potential temporal coherency. In this paper, we explore the use of Temporal Occlusion Coherence (TOC) to accelerate visibility culling for time-varying volume rendering. In our algorithm, the opacity of volume blocks is encoded by means of Plenoptic Opacity Functions (POFs). A coherence-based block fusion technique is employed to coalesce time-coherent data blocks over a span of time steps into a single, representative block. Then POFs need only be computed for these representative blocks. To quickly determine the subvolumes that do not require updates in their visibility status for each subsequent time step, a hierarchical “TOC tree ” data structure is constructed to store the spans of coherent time steps. To achieve maximal culling potential, while remaining conservative, we have extended our previous POF into an Optimized POF (OPOF) encoding scheme for this specific scenario. To test our general TOC and OPOF approach, we have designed a parallel time-varying volume rendering algorithm accelerated by visibility culling. Results from experimental runs on a 32-processor cluster confirm both the effectiveness and scalability of our approach.
Adaptive Multi-valued Volume Data Visualization Using Data-dependent Error Metrics
- in Proceedings of the Third IASTED International Conference on Visualization, Imaging, and Image Processing (VIIP 2003), The International Association of Science and Technology for Development (IASTED
, 2003
"... Adaptive, and especially view-dependent, volume visualization is used to display large volume data at interactive frame rates preserving high visual quality in specified or implied regions of importance. In typical approaches, the error metrics and refinement oracles used for viewdependent rendering ..."
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Cited by 3 (2 self)
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Adaptive, and especially view-dependent, volume visualization is used to display large volume data at interactive frame rates preserving high visual quality in specified or implied regions of importance. In typical approaches, the error metrics and refinement oracles used for viewdependent rendering are based on viewing parameters only. The approach presented in this paper considers viewing parameters and parameters for data exploration such as isovalues, velocity field magnitude, gradient magnitude, curl, or divergence. Error metrics are described for scalar fields, vector fields, and more general multi-valued combinations of scalar and vector field data. The number of data being considered in these combinations is not limited by the error metric but the ability to use them to create meaningful visualizations. Our framework supports the application of visualization methods such as isosurface extraction to adaptively refined meshes. For multi-valued data exploration purposes, we combine extracted mapping with color information and/or streamlines mapped onto an isosurface. Such a combined visualization seems advantageous, as scalar and vector field quantities can be combined visually in a highly expressive manner.
VISUALISATION OF THE NUMERICAL SOLUTION OF PARTIAL DIFFERENTIAL EQUATION SYSTEMS IN THREE SPACE DIMENSIONS AND ITS IMPORTANCE FOR MATHEMATICAL MODELS IN BIOLOGY
"... (Communicated by Qing Nie) Abstract. Numerical analysis and computational simulation of partial differential equation models in mathematical biology are now an integral part of the research in this field. Increasingly we are seeing the development of partial differential equation models in more than ..."
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Cited by 2 (0 self)
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(Communicated by Qing Nie) Abstract. Numerical analysis and computational simulation of partial differential equation models in mathematical biology are now an integral part of the research in this field. Increasingly we are seeing the development of partial differential equation models in more than one space dimension, and it is therefore necessary to generate a clear and effective visualisation platform between the mathematicians and biologists to communicate the results. The mathematical extension of models to three spatial dimensions from one or two is often a trivial task, whereas the visualisation of the results is more complicated. The scope of this paper is to apply the established marching cubes volume rendering technique to the study of solid tumour growth and invasion, and present an adaptation of the algorithm to speed up the surface rendering from numerical simulation data. As a specific example, in this paper we examine the computational solutions arising from numerical simulation results of a mathematical model of malignant solid tumour growth and invasion in an irregular heterogeneous three-dimensional domain, i.e., the female breast. Due to the different variables that interact with each other, more than one data set may have to be displayed simultaneously, which can be realized through transparency blending. The usefulness of the proposed method for visualisation in a more general context will also be discussed. 1. Introduction. Mathematical
