1. MEAD: Volume Visualization David Porter, U. Minnesota/LCSE Data Pipeline A3D HVR Tiled Commas Output Windows & Unix Formats & Frameworks linking to MEAD

2. Data Pipeline Hydro-code: WRF/COMMAS ROMS Raw Fields (U,V,W,…) Formats: (HDF5, WRF, cdump) Data Post-Processing: A3D Block-Tree Hierarchies Derived Fields (Humidity, Vorticity) Volume Visualization: HVR Raster Data: (Images, Movies)

3. A3D: More Than Just Compression, Conversion, Scaling Reads in raw 3D fields onto a stack Tiled cdump, BoF, HDF4,  HDF5, netCDF? Performs calculations on this stack fields +-*/, d/dx, spatial filters, map from sigma-coords. (mm5) Produces statistical reductions power spectra,structure functions, histograms,radial & vertical profiles BoF, BoB, SoF, SoB filescross-correlations as well as Block Tree hierarchies for visualization. Energy Spectra(k) MLT coefficients(Z) MM5 simulation

4. Block Tree Hierarchy: Basic Idea Illustration: A 2 level hierarchy in 2D 16x16 array is split into 4 tiles Each tile is sampled at a stride of 2x2 8x8 array of info in each node of tree

5. 3D Block-Tree A 3D mipmap Browse even the largest data sets at interactive speeds. Full size of data only limited by disk. Trees can be both logically and spatially irregular. Highest resolution need not span entire domain. Block size tuned to both hardware and application. = 128x128x64 256 32 4 1

6. HVR Organize voxel data into a Block-Tree hierarchy Stage large volumes of data on disk Data compression: 1 byte per voxel & Tree Pruning Control rendering quality vs. speed via tree traversal DCOM rendering server: HVR-SERVER Use key framing to specify complex path in space and time Interactive GUI driven: HVR-GUI Tree hierarchy + key framing facilitate remote rendering Root of Block-Tree hierarchy ideal for local key framing needs Key framing software delineates division of labor between Local and remote resources & work. Optimized use of network bandwidth

7. Rendering Tolerances Tolerances based on Angle subtended by voxel Color map index error Absolute resolution (For speed only) 2D illustration Quad-tree hierarchy Each tile might be 256x256

8. Tolerance: Based on Angle Subtended Viewpoint If a voxel at a given resolution subtends to great an angle, then scan down to finer resolution.

9. Tolerance: Based on Max. Error in Value Nodes have bound on error Const color  no error Stop at nodes w/ no error

10. Remote Rendering: Routines Local HVR-GUI HVR-SERVER MOVIE PLAYER Remote HVR-SERVER

11. Remote Rendering: Data Local Finder Bricks Key Frame Parameters Color & Alpha LUT Low-Mid Sized Movies Remote Block-Tree Hierarchy Key Frame Parameters Color & Alpha LUT Low-Mid Sized Movies Power Wall Movies TinyKB- SmallMB MediumGB LargeTB+

12. Example: Tiled COMMAS PC-cluster simulation produces “tiled output” Titan cluster Logistics: 10 3 files randomly distributed across ~10 2 nodes Tiles are collected to post-processing hosts SCP to LCSE PC-rendering cluster Logistics: cdump files redistributed across 10-100 nodes A3D reads tiled cdumps and produces derived scalar volume data in block tree format. Fields: W, vorticity, cloud water (*.hv files) Logistics: hv files redistributed to rendering cluster HVR produces images & movies Logistics: Need data a base: MySQL

13. COMMAS: 96x96x36 (4x4 tiles)

14. COMMAS: 250x250x72 (5x5 tiles)

15. Porting to Unix WindowsUnixOpenGL WGLGLUT DCOMCORBA? Condor? GUI: MFCFLTK? XML? Command line? Subroutine? Your framework?

16. Data Formats I’m looking for a few good data sets. WRF ROMS In a few relevant formats netCDF HDF5 Data Sets Please …

17. Frameworks I’m looking for a few good frameworks Connecting a few relevant centers APIs Please …

18. Web Link http://www.lcse.umn.edu Downloads of volume rendering apps for your PC Downloads of software under GNU GPL Many volume rendered movies User Guide to the Graphical user interface: hvr_gui Description of the Hierarchical Volume Rendering server hvr_server Software for producing volume data in Block Tree format

19. LCSE MEAD Milestones (Q1)Simplified code (COMMAS) running w/ SHMOD HVR Vol Vis of WRF datasets via data postproc w/ a3d (Q2)Simplified code with dynamic load balancing HVR vis of ROMS data. (Q3)Simplified code running in fault tolerant mode (Q4)Simplified code running on TeraGrid HVR vis of data on TeraGrid.