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NUG PPPL, June 12-13, 2006, AVS/Express and VisIt Training


The objective of this tutorial is to show basic use of AVS/Express and VisIt with example 2D and 3D data. We show how to import data, make isosurfaces, display vector fields and use streamlines. AVS/Express is a very flexible (serial) development environment to build visualization applications. For many users it has "too many" options and learning how to use it can take some time. However if the data is not too big, it offers the most flexible interaface to add custom modules. VisIt on the other hand is more of a "closed package" type of tool with a plugin development API. It provides a nice friendly user interface and has the advantage of using a distributed and parallel architecture that allows users to run a client in a desktop machine and a backend (parallel or serial) in a remote location where the data was produced.

Before we start

You should have AVS/Express and VisIt installed in your computer. Follow the instructions below to install.

AVS/Express Download and NERSC license checkout

AVS/Express 7.1 can be downloaded from
Express download

AVS/Express and other visualization software licenses can be checked out through the NERSC web site using your NIM username and password. Click here for details. Note that you need to do the checkout using a browser from the computer where you will run Express. More information on AVS/Express at NERSC

AVS/Express needs some enviroment variables set up. This csh script will set them up. Please adapt to you favorite shell and your platform/OS, XP_ROOT should point at your installation directory. AVS/Express provides a script to test if your platform is supported. Run xp_mach (in the express/bin directory). Use the answer to substitute in this script.


setenv XP_ROOT /usr/local/express7.1/express
setenv LD_LIBRARY_PATH $XP_ROOT/lib/linux_64/
setenv PATH "$PATH":$XP_ROOT/bin/linux_64
setenv LANG US_eng
setenv MACHINE linux_64

VisIt Download

VisIt is free parallel visualization tool that runs on Unix and PC platforms. It's developed at the Lawrence Livermore National Laboratory. Please refer to for downloads and installation details. More information on VisIt at NERSC


Example data

AVS/Express example applications

These are simple applications. To load them, choose "load application" and point to the ".v" file. These files are text files that you can edit and modify.

Power Point Presentation