Unstructured Data Partitioning for Large Scale Visualization
CSCAPES Workshop
June, 2008
Kenneth MorelandSandia National Laboratories
Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company,for the United States Department of Energy’s National Nuclear Security Administration
under contract DE-AC04-94AL85000.
The Parallel Visualization Pipeline
Read
Isosurface
Reflect
Render
The Parallel Visualization Pipeline
Read
Isosurface
Reflect
Render
Read
Isosurface
Reflect
Render
Read
Isosurface
Reflect
Render
Read
Isosurface
Reflect
Render
Data Parallel Pipelines
• Duplicate pipelines run independently on different partitions of data.
Data Parallel Pipelines
• Duplicate pipelines run independently on different partitions of data.
Data Parallel Pipelines
• Some operations will work regardless.– Example: Clipping.
Data Parallel Pipelines
• Some operations will work regardless.– Example: Clipping.
Data Parallel Pipelines
• Some operations will work regardless.– Example: Clipping.
Data Parallel Pipelines
• Some operations will have problems.– Example: External Faces
Data Parallel Pipelines
• Some operations will have problems.– Example: External Faces
Data Parallel Pipelines
• Ghost cells can solve most of these problems.
Data Parallel Pipelines
• Ghost cells can solve most of these problems.
The Parallel Visualization Pipeline
Read
Isosurface
Reflect
Render
Read
Isosurface
Reflect
Render
Read
Isosurface
Reflect
Render
Read
Isosurface
Reflect
Render
Parallel Rendering
Parallel Rendering
Tiled Displays
Rendering Translucent Geometry
Unstructured Volume Rendering in Parallel
Unstructured Volume Rendering in Parallel
Unstructured Volume Rendering in Parallel
Unstructured Volume Rendering in Parallel
Unstructured Volume Rendering in Parallel
Mesh Partitioning
Partitioning on Spatial Structure: K-D Tree
K-D Trees Provide Query Structures
What elements are closest to here?
K-D Trees Provide Query Structures
What regions / elements intersect this view frustum?
K-D Trees Provide Query Structures
What is the visibility order of the regions from this viewpoint? 1
2 3
4
5 6
7
8
Reconstructing Connectivity Information
May not be unique.
Neighbor info usually missing.
Reconstructing Connectivity Information
Future Work
• Code Optimization and Cleanup• Integration of other partitioning algorithms.• Better Data Type Support.• Better Temporal Support.