1. VisIt Team April 24, 2012 VisIt Update, DOE CGF 2012 PySide GUI, H. Krishnan FTLE from tokamak, Childs, Krishnan, & Sugiyama (MIT)

2. Outline  Features released in the last year  Projects impacted (partial list)  Upcoming features  Publications & Outreach

3. Outline  Features released in the last year  Projects impacted (partial list)  Upcoming features  Publications & Outreach

4. 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.

5. 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 view coarse patches Highly zoomed view very fine patches

6. Example: 6 levels, 32819 patches mesh refines as image zoomed Level 5 159 patches Level 4 140 patches Level 3 71 patches Level 6 121 patches

7. Multi-resolution demo

8.  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

9. 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!

10. Particle Advection Streamlines seeded by a separate plot, via VisIt’s named selection mechanism.

11. 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

12. FTLE in VisIt  New FTLE operator available in V2.5 FTLE from tokamak, Childs, Krishnan, & Sugiyama (MIT) FTLE from tokamak, Childs, Krishnan, & Sugiyama (MIT) FTLE from ocean modeling, Ozgokmen (Univ. of Miami) FTLE from ocean modeling, Ozgokmen (Univ. of Miami)

13. 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

14. 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 scheduler mdserver Compute engine Local computerRemote computer Submit job

15. Outline  Features released in the last year  Projects impacted (partial list)  Upcoming features  Publications & Outreach

16. 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

17. 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

18. Effect of back scatter on input beams Reduced input beam corresponds to high back scatter Input beamBack 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.

19. Outline  Features released in the last year  Projects impacted (partial list)  Upcoming features  Publications & Outreach

20.  Stream surfaces  VRF  OpenCL  Staggered grids

21. Outline  Features released in the last year  Projects impacted (partial list)  Upcoming features  Publications & Outreach

22. 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

23. 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