Presentation on theme: "Parallel Visualization Kenneth Moreland Sandia National Laboratories Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin."— Presentation transcript:
Parallel Visualization Kenneth Moreland Sandia National Laboratories Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energys National Nuclear Security Administration under contract DE-AC04-94AL85000.
The Parallel Visualization Pipeline Read Isosurface Reflect Render
K-D Trees Provide Query Structures What is the visibility order of the regions from this viewpoint?
ParaView Architecture for Interactive Remote Parallel Visualization Three Tier Data Server Render Server Client
Standalone Client Data Server Render Server
Client-Server Client Data Server Render Server Socket
Client-Render Server-Data Server Client Data Server Render Server Socket Socket × N
Client-Server Client Data Server Render Server Socket Minimize Communication Render Remotely Send Images
Rendering Modes Still Render Full detail render. Interactive Render Sacrifices detail for speed. Provides quick rendering rate. Used when interacting with 3D view.
Level of Detail (LOD) Geometric decimation. Used only with Interactive Render Original DataDivisions: 50x50x50Divisions: 10x10x10
Image Size LOD ParaViews parallel rendering overhead proportional to image size. To speed up interactive rendering, ParaView can render smaller sized images and inflate them. Original DataSubsample Rate: 2 pixelsSubsample Rate: 4 pixelsSubsample Rate: 8 pixels
Color Depth LOD Squirt is used to transfer images from server to client. Squirt is a run length encoder optimized for images. Run lengths improved by masking out some color bits. 24-bit mask19-bit mask10-bit mask
Summary Most visualization algorithms are embarrassingly parallel. Ghost cells can eliminate need for communication. Simulation dumps are often missing connectivity information. Geometry sizes grow quickly, image sizes dont. Sort-last rendering scales well in this regard. Avoid bottlenecks caused by saturating any process with geometry. Remote interactivity is important. Parallel resources are seldom local. Interactivity can be maintained with levels of detail. Always be clear what you are using. Make sure the full detail shows up eventually.