CEDMAV Publications


H.T. Vo, D.K. Osmari, B. Summa, J.L.D. Comba, V. Pascucci, C.T. Silva. “Streaming-Enabled Parallel Dataflow Architecture for Multicore Systems,” In Computer Graphics Forum, Vol. 29, No. 3, Wiley-Blackwell, pp. 1073--1082. Aug, 2010.
DOI: 10.1111/j.1467-8659.2009.01704.x


We propose a new framework design for exploiting multi-core architectures in the context of visualization dataflow systems. Recent hardware advancements have greatly increased the levels of parallelism available with all indications showing this trend will continue in the future. Existing visualization dataflow systems have attempted to take advantage of these new resources, though they still have a number of limitations when deployed on shared memory multi-core architectures. Ideally, visualization systems should be built on top of a parallel dataflow scheme that can optimally utilize CPUs and assign resources adaptively to pipeline elements. We propose the design of a flexible dataflow architecture aimed at addressing many of the shortcomings of existing systems including a unified execution model for both demand-driven and event-driven models; a resource scheduler that can automatically make decisions on how to allocate computing resources; and support for more general streaming data structures which include unstructured elements. We have implemented our system on top of VTK with backward compatibility. In this paper, we provide evidence of performance improvements on a number of applications.


E.W. Bethel, C.R. Johnson, S. Ahern, J. Bell, P.-T. Bremer, H. Childs, E. Cormier-Michel, M. Day, E. Deines, P.T. Fogal, C. Garth, C.G.R. Geddes, H. Hagen, B. Hamann, C.D. Hansen, J. Jacobsen, K.I. Joy, J. Kr├╝ger, J. Meredith, P. Messmer, G. Ostrouchov, V. Pascucci, K. Potter, Prabhat, D. Pugmire, O. Rubel, A.R. Sanderson, C.T. Silva, D. Ushizima, G.H. Weber, B. Whitlock, K. Wu. “Occam's Razor and Petascale Visual Data Analysis,” In Journal of Physics: Conference Series, Journal of Physics: Conference Series, Vol. 180, No. 012084, pp. (published online). 2009.
DOI: 10.1088/1742-6596/180/1/012084


One of the central challenges facing visualization research is how to effectively enable knowledge discovery. An effective approach will likely combine application architectures that are capable of running on today's largest platforms to address the challenges posed by large data with visual data analysis techniques that help find, represent, and effectively convey scientifically interesting features and phenomena.

C.D. Hansen, C.R. Johnson, V. Pascucci, C.T. Silva. “Visualization for Data-Intensive Science,” In The Fourth Paradigm: Data-Intensive Science, Edited by S. Tansley and T. Hey and K. Tolle, Microsoft Research, pp. 153--164. 2009.

K. Potter, A. Wilson, P.-T. Bremer, D. Williams, C. Doutriaux, V. Pascucci, C.R. Johhson. “Visualization of Uncertainty and Ensemble Data: Exploration of Climate Modeling and Weather Forecast Data with Integrated ViSUS-CDAT Systems,” In J. Phys.: Conf. Ser., Vol. 180, No. 012089, IOP Publishing, pp. 012089. July, 2009.
DOI: 10.1088/1742-6596/180/1/012089

K. Potter, A. Wilson, P.-T. Bremer, D. Williams, C. Doutriaux, V. Pascucci, C.R. Johnson. “Ensemble-Vis: A Framework for the Statistical Visualization of Ensemble Data,” In Proceedings of the 2009 IEEE International Conference on Data Mining Workshops, pp. 233--240. 2009.

J. Tierny, A. Gyulassy, E. Simon, V. Pascucci. “Loop Surgery for Volumetric Meshes: Reeb Graphs Reduced to Contour Trees,” In IEEE Transactions on Visualization and Computer Graphics, Proceedings of the 2009 IEEE Visualization Conference, Vol. 15, No. 6, pp. 1177--1184. Sept/Oct, 2009.
DOI: 10.1109/TVCG.2009.163

H.T. Vo, D.K. Osmari, B. Summa, J.L.D. Comba, V. Pascucci, C.T. Silva. “Parallel Dataflow Scheme for Streaming (Un)Structured Data,” SCI Technical Report, No. UUSCI-2009-004, SCI Institute, University of Utah, 2009.


E.W. Bethel, H. Childs, A. Mascarenhas, V. Pascucci, Prabhat. “Scientific Data Management Challenges in High Performance Visual Data Analysis,” In Scientific Data Management: Challenges, Existing Technology, and Deployment, Chapman Hall/CRC Press, 2008.


J. Bennett, V. Pascucci, K.I. Joy. “Genus Oblivious Cross Parameterization: Robust Topological Management of Intersurface Maps,” In Proceedings of Pacific Graphics 2007, 2007.

E.W. Bethel, C.R. Johnson, K. Joy, S. Ahern, V. Pascucci, H. Childs, J. Cohen, M. Duchaineau, B. Hamann, C.D. Hansen, D. Laney, P. Lindstrom, J. Meredith, G. Ostrouchov, S.G. Parker, C.T. Silva, A.R. Sanderson, X. Tricoche. “SciDAC Visualization and Analytics Center for Enabling Technology,” In Journal of Physics, Conference Series, Vol. 78, No. 012032, pp. (published online). 2007.

E.W. Bethel, C.R. Johnson, C. Aragon, Prabhat, O. Rübel, G. Weber, V. Pascucci, H. Childs, P.-T. Bremer, B. Whitlock, S. Ahern, J. Meredith, G. Ostrouchov, K. Joy, B. Hamann, C. Garth, M. Cole, C.D. Hansen, S.G. Parker, A.R. Sanderson, C.T. Silva, X. Tricoche. “DOE's SciDAC Visualization and Analytics Center for Enabling Technologies - Strategy for Petascale Visual Data Analysis Success,” In CTWatch Quarterly, Vol. 3, No. 4, 2007.

P.-T. Bremer, E.M. Bringa, M.A. Duchaineau, A. Gyulassy, D. Laney, A. Mascarenhas, V. Pascucci. “Topological Feature Extraction and Tracking,” In Proceedings of SciDAC 2007 -- Scientific Discovery Through Advanced Computing, Boston, MA, USA, Vol. 78, Journal of Physics Conference Series, pp. 012032 (5pp). June, 2007.

P.-T. Bremer, V. Pascucci. “A Practical Approach to Two-Dimensional Scalar Topology,” In Mathematics and Visualization, Springer Verlag, pp. 151--169. 2007.
ISBN: Online ISBN 978-3-540-70823-0 Series Title Mathematics and Visualization Series ISSN 1
DOI: 10.1007/978-3-540-70823-0_11


Computing and analyzing the topology of scalar fields has proven to be a powerful tool in a wide variety of applications. In recent years the field has evolved from computing contour trees of two-dimensional functions to Reeb graphs of general two-manifolds, analyzing the topology of time-dependent volumes, and finally to creating Morse-Smale complexes of two and three dimensional functions. However, apart from theoretical advances practical applications depend on the development of robust and easy to implement algorithms. The progression from initial to practical algorithms is evident, for example, in the contour tree computation where the latest algorithms consist of no more than a couple of dozens lines of pseudo-code. In this paper we describe a similarly simple approach to compute progressive Morse-Smale complexes of functions over two-manifolds. We discuss compact and transparent data-structures used to compute and store Morse-Smale complexes and demonstrate how they can be used to implement interactive topology based simplification. In particular, we show how special cases arising, for example, from manifolds with boundaries or highly quantized functions are handled effectively. Overall the new algorithm is easier to implement and more efficient both run-time and storage wise than previous approaches by avoiding to refine a given triangulation.

S.P. Callahan, L. Bavoil, V. Pascucci, C.T. Silva. “Progressive Volume Rendering of Large Unstructured Grids,” In IEEE Transactions on Visualization and Computer Graphics, Vol. 13, No. 1, pp. 1307-1314. 2007.

A. Gyulassy, V. Natarajan, B. Hamann, V. Pascucci. “Efficient Computation of Morse-Smale Complexes for Three-dimensional Scalar Functions,” In IEEE Transactions on Visualization and Computer Graphics, Note: (presented at IEEE VIS 2007), 2007.

A. Gyulassy, V. Natarajan, B. Hamann, M. Duchaineau, V. Pascucci, E. Bringa, A. Higginbotham. “Topologically Clean Distance Fields,” In IEEE Transactions on Visualization and Computer Graphics, Note: (presented at IEEE VIS 2007), 2007.

D. Laney, P.-T. Bremer, A. Mascarenhas, P. Miller, V. Pascucci. “Understanding the Structure of the Turbulent Mixing Layer in Hydrodynamic Instabilities,” In IEEE Transactions on Visualization and Computer Graphics, Vol. 13, No. 1, pp. 1053--1060. January, 2007.

V. Pascucci, G. Scorzelli, P.-T. Bremer, A. Mascarenhas. “Robust On-line Computation of Reeb Graphs: Simplicity and Speed,” In ACM Transactions on Graphics: ACM SIGGRAPH 2007 Papers, ACM Press, New York, NY, USA pp. 1057--1066. 2007.

H.T. Vo, S.P. Callahan, P. Lindstrom, V. Pascucci, C.T. Silva. “Streaming Simplification of Tetrahedral Meshes,” In IEEE Transactions on Visualization and Computer Graphics, Vol. 13, No. 1, pp. 145--155. Jan/Feb, 2007.

G.H. Weber, P.-T. Bremer, V. Pascucci. “Topological Landscapes: A Terrain Metaphor for Scientific Data,” In IEEE Transactions on Visualization and Computer Graphics, Note: (presented at IEEE VIS 2007), 2007.