Download - VisIt Update, DOE CGF 2012
VisIt TeamApril 24, 2012
VisIt Update, DOE CGF 2012
PySide GUI, H. Krishnan FTLE from tokamak, Childs, Krishnan, & Sugiyama (MIT)
Outline Features released in the last year Projects impacted (partial list) Upcoming features Publications & Outreach
Outline Features released in the last year Projects impacted (partial list) Upcoming features Publications & Outreach
Support for custom user interfaces written in Python via PySide.
PySide is a LGPL Python library that wraps Qt.
PySide is now distributed with VisIt and available from VisIt’s CLI.
Dynamically create and control Qt GUIs via Python.
Supports GUIs created with Qt’s Designer.
2D AMR based multi-resolution capability
Provide multi-resolution display of data from AMR meshes
Culling of data is at the patch level
Only data required for image is read
User specifies smallest cell size to display
Patches displayed are updated as the user pans and zooms the image
Un-zoomed viewcoarse patches
Highly zoomed viewvery fine patches
Example: 6 levels, 32819 patchesmesh refines as image zoomed
Level 5159
patches
Level 4140 patchesLevel 3
71 patches
Level 6121
patches
On Sequoia (and similar platforms) the available memory per core will constrain global data structures used for simulation restarts and graphics dumps.
Transition from global metadata to implicit, local, or distributed tree based data structures:
Support for Distributed Mesh Metadata
Current Global Constructs:• Multi-Domain Object Specification• Domain Boundary Information• AMR Nesting Hierarchies• Spatial Extents and Variable Extents
Particle Advection Particle advection: displacing a massless
particle tangent to the velocity field System: Parallel Integral Curve System
(PICS) See Hank’s talk on Thurs
Accomplishments: Continued work on hardening particle
advection infrastructure Including more robust pathlines and AMR
support Reverse pathlines Code sprint!
Finite-Time Lyapunov Exponents (FTLE)
Visualize manifolds of maximal stretching in a flow, as indicated by dense particles
Finite-Time Lyapunov Exponent (FTLE)
Courtesy Garth
FTLE in VisIt New FTLE operator available in V2.5
FTLE from tokamak, Childs, Krishnan, & Sugiyama
(MIT)FTLE from ocean modeling, Ozgokmen (Univ. of Miami)
VTK 5.8 Upgrade• VisIt updated to use new API
• Faster renderer• Allowed some code to be removed
• Restored mangled Mesa support in VTK• Performance improvements in VTK’s renderer
• Don’t check GL state during render • 5x faster when displaying back from remote
computer• Fixed VTK text rendering bugs• Fixed VTK’s specular highlights with color
texturing• Need to migrate fixes back to VTK main
Enhanced Support for Windows
• Visual Studio 2010• Build programs without console• SSH tunneling through gateway computer• Parallel engine using MSMPI• Launch VisIt on Windows HPC clusters
• Allow parallel compute engine to launch in batch and start mdserver
Windows HPC
schedulermdserverCompute
engine
Local computer Remote computer
launch launch
Submit job
Outline Features released in the last year Projects impacted (partial list) Upcoming features Publications & Outreach
Understanding laser beam interactions at the National Ignition Facility
The National Ignition Facility (NIF) is 3 football fields in size
192 lasers are focused on the target about a cm in size
The goal is to ignite the deuterium and tritium fuel in the target
The Nation Ignition Facility
A hohlraum
Simulated 2 beams to understand back scatter
Simulating 2 beams hitting the target to understand how much backscatter is present and if multiple beams impacts the results. Previous simulations could only simulate a single beam.
Simulation facts: Ran on 32k cores contained 220 billion zones
Visualization details: Interactively set up the movies Created the movies in batch Used either 1k or 2k cores 2 minutes to process a time state 5 hours to generate a movie
Effect of back scatter on input beamsReduced input beam corresponds to high back scatter
Input beam Back scatter
Were able to demonstrate an oscillatory behavior where the back scatter intensity would increase, leading to a decrease in the input intensity, which lead to a decrease in the back scatter intensity, which lead to an increase in the input intensity, etc.
Outline Features released in the last year Projects impacted (partial list) Upcoming features Publications & Outreach
Outline Features released in the last year Projects impacted (partial list) Upcoming features Publications & Outreach
Publications D. Camp, C. Garth, H. Childs, D. Pugmire, and K. I. Joy. Streamline
Integration Using MPI-Hybrid Parallelism on a Large Multicore Architecture. IEEE Transactions on Visualization and Computer Graphics, 17:1702–1713, 2011
D. Camp, H. Childs, A. Chousaria, C. Garth, and K. I. Joy. Evaluating the Benefits of An Extended Memory Hierarchy for Parallel Streamline Algorithms. In Proceedings of the IEEE Symposium on Large Data Visualization and Analysis (LDAV), pages 57–64, October 2011
H. Childs, E. Brugger, B. Whitlock, J. Meredith, S. Ahern, K. Bonnell, M. Miller, G. H. Weber, C. Harrison, D. Pugmire, T. Fogal, C. Garth, A. Sanderson, E. W. Bethel, M. Durant, D. Camp, J. M. Favre, O. Ruebel, P. Navratil, M. Wheeler, P. Selby, and F. Vivodtzev. VisIt: An End-User Tool For Visualizing and Analyzing Very Large Data. In Proceedings of SciDAC 2011, July 2011
C. Harrison, H. Childs, and K. P. Gaither. Data-Parallel Mesh Connected Components Labeling and Analysis. In Proceedings of EuroGraphics Symposium on Parallel Graphics and Visualization, pages 131–140, April 2011
A.R. Sanderson, G. Chen, X. Tricoche, E. Cohen. “Understanding Quasi-Periodic Fieldlines and Their Topology in Toroidal Magnetic Fields,” In Proceedings of TopoInVis 2011, pp. (to appear). 2011.
B. Whitlock, J. Favre, J. Meredith, Parallel In Situ Coupling with a fully featured Visualization System. In Proceedings of EuroGraphics Symposium on Parallel Graphics and Visualization, pages 101-109, April 2011
Documentation and Training• VisIt Tutorial:
• ISC11, DOE ACTS, SciDAC, Boise State, UCSC, HiPACC
• Visualization with VisIt Class• Materials updated• Materials created for 2nd day covering advanced
features• Taught at ARL in May 2011• Taught at LLNL in September 2011
• Python Interface Manual• Python doc strings updated & added for all
functions• Automatic generation from source code