Quick Demo for Making a Mesh Plot with VisIt

This is a quick demo of how to make a mesh plot using VisIt. This demo uses VisIt sample data.

For this demo you are going to run VisIt on DaVinci.

Note that the best way to run VisIt is to install VisIt on your local machine and run a remote compute engine on DaVinci.
How to do this is explained on http://www.nersc.gov/nusers/services/software/apps/visualization/visit/visit_davinci_remote.php.

To get started with the demo:

  • log on to DaVinci
  • type module load visit
  • type visit
Once VisIt starts, you will need to (1) load a sample data set, (2) select Mesh plot as the type of plot you want to make, (3) click the Draw button to render the mesh. These steps are illustrated below with screenshots.

Once you start visit, click on File at the upper left of the VisIt 1.11.1 window. That opens the File open GUI you see in the screenshot. Enter davinci.nersc.gov into the Host field as shown. Enter the path shown in the Path field exactly as shown. Enter * in the Filter field.

Select the file curv3d.silo as selected in the screenshot, and then click the OK button.

After that, a GUI will pop up asking whether you want to run a serial or parallel job. Choose serial for this demo and click OK.

About half way down the VisIt 1.11.1 window on the left is the Plots menu. Click that and you'll see a list of plots. Select Mesh as your type, and you will see the only mesh available for the selected data file as shown in the screenshot below. Click on curvmesh3d.

After that, you will see in the box above the Plots menu, the plot 1:Mesh - curvmesh3d, but Window 1 will be empty. You need to click on the Draw button in the VisIt 1.11.1 window for the image to appear. The image that you see below resulted from rotating the image that first appeared.

To do plot the mesh in your data file, you will follow the steps above. What you will do different is the following:

  • In the first step, the File open step, you will need enter the path to the directory where your data file is located, and the select your file from the list of Files. If VisIt does not recognize the the file format from the extension of the file, then you need to explicitly select the file format from the drop down list next to Open file as type:.
     
    Note that if your file is in HDF5 format, then VisIt will expect your file to have the extention "h5". If your file does not have that extension, then VisIt will not know that it is an HDF5 file, and there is not "h5" choice in the drop down list of formats. What you can easily do, however, is create a symbolic link to your file, e.g.,
                   ln -s h5.my_data_file h5.my_data_file.h5.
    Then select the file h5.my_data_file.h5 from the file list.
     
  • The second step is the same.

More information about VisIt, including a tutorial can be found at the VisIt Web sites:
          http://www.llnl.gov/visit
          http://www.visitusers.org/index.php?title=Short_Tutorial

Information about running VisIt at NERSC can be found at
          http://www.nersc.gov/nusers/services/software/apps/visualization/visit/