Using ParaView to Visualize CTH Data
This How-To guide focuses on how to use ParaView (http://www.paraview.org) to visualize CTH data. As a brief backgound, ParaView is an open-source parallel visualization tool funded by the Department of Energy. From the ParaView web page:
"The goal of the project is to develop scalable parallel processing tools with an emphasis on distributed memory implementations. The project includes parallel algorithms, infrastructure, I/O, support, and display devices."
ARL has worked with Kitware to provide Xdmf (http://xdmf.org/) dataset functionallity in ParaView. As a consequence, ParaView natively reads Xdmf datasets and can perform certain ARL-specific type operations on those datasets. One of those capabilities is to extract CTH parts from the XDMF dataset.
This guide is not a general purpose document on how to use ParaView. There is an excellent user's guide available at the ParaView web site (ParaView User's Guide)
Visualizing CTH Data
Start paraview, select File->Open Data. You will be presented with a standard file selection dialog box. Select "Xdmf" from the option menu of file types. See Figure 1.
Either double-click the data file you wish to load, or click once and press OK. You will next be presented with a Dialog box to choose which Xdmf Domain to use. In most cases, CTH data has only Domain, so select Ok.
Next, you need to select the variables you want available for visualization. By default, ParaView enables all variables. You may want to disable some on large datasets to reduce memory usage, and to speed up loading of the data. In this step, you can also set the striding though the data if you want faster loading or a smaller memory footprint. You can also set which timestep you wish to view. When these choices have been made, press Accept. See Figure below.
Note that the "make a change, then execute" model is a standard idiom in ParaView. Unlike most other visualization packages, ParaView requires the extra step of a confirmation before it executes an operation. Since ParaView is designed to work on large datasets, this prevents costly operations from being continuously executed.
The next step is to create the isosurfaces representing the differnet material fractions. Fortunately, ParaView provides a convient method for generating this data. Go to the Filters menu and select "Extract CTH Parts".
Once the menu appear in the panel, turn off the Clip Plane, hit Accept, and viola, an isosurface for a particular material fraction. Repeat for any other material fractions that need to be visualized.
Now continue to visualize as normal in ParaView. Again, the User's guide for ParaView is at http://www.paraview.org/files/v1.6/ParaViewUsersGuide.PDF