Image-space decomposition algorithms for sort-first parallel volume rendering of unstructured grids
Author
Kutluca, H.
Kurç, T. M.
Aykanat, Cevdet
Date
2000Source Title
Journal of Supercomputing
Print ISSN
0920-8542
Electronic ISSN
1573-0484
Publisher
Springer
Volume
15
Issue
1
Pages
51 - 93
Language
English
Type
ArticleItem Usage Stats
132
views
views
84
downloads
downloads
Abstract
Twelve adaptive image-space decomposition algorithms are presented for sort-first parallel direct volume rendering (DVR) of unstructured grids on distributed-memory architectures. The algorithms are presented under a novel taxonomy based on the dimension of the screen decomposition, the dimension of the workload arrays used in the decomposition, and the scheme used for workload-array creation and querying the workload of a region. For the 2D decomposition schemes using 2D workload arrays, a novel scheme is proposed to query the exact number of screen-space bounding boxes of the primitives in a screen region in constant time. A probe-based chains-on-chains partitioning algorithm is exploited for load balancing in optimal 1D decomposition and iterative 2D rectilinear decomposition (RD). A new probe-based optimal 2D jagged decomposition (OJD) is proposed which is much faster than the dynamic-programming based OJD scheme proposed in the literature. The summed-area table is successfully exploited to query the workload of a rectangular region in constant time in both OJD and RD schemes for the subdivision of general 2D workload arrays. Two orthogonal recursive bisection (ORB) variants are adapted to relax the straight-line division restriction in conventional ORB through using the medians-of-medians approach on regular mesh and quadtree superimposed on the screen. Two approaches based on the Hilbert space-filling curve and graph-partitioning are also proposed. An efficient primitive classification scheme is proposed for redistribution in 1D, and 2D rectilinear and jagged decompositions. The performance comparison of the decomposition algorithms is modeled by establishing appropriate quality measures for load-balancing, amount of primitive replication and parallel execution time. The experimental results on a Parsytec CC system using a set of benchmark volumetric datasets verify the validity of the proposed performance models. The performance evaluation of the decomposition algorithms is also carried out through the sort-first parallelization of an efficient DVR algorithm.
Keywords
AlgorithmsAnti-Aliasing
Computer Architecture
Computer Systems Programming
Data Storage Equipment
Graph Theory
Image Analysis
Image Quality
Response Time (Computer Systems)
Sorting
Chains-on-Chains Partitioning
Direct Volume Rendering (DVR)
Graph Partitioning
Hilbert Space-Filling Curve
Image-Space Decomposition Algorithms
Jagged Decomposition
Orthogonal Recursive Bisection (ORB)
Rectilinear Decomposition (RD)
Sort-First Parallelism
Parallel Processing Systems