== VisIt ==
https://wci.llnl.gov/simulation/computer-codes/visit/ Visit Home Page]

VisIt is an Open Source, interactive, scalable, visualization, animation and analysis tool. From Unix, Windows or Mac workstations, users can interactively visualize and analyze data ranging in scale from small (<10^1^ core) desktop-sized projects to large (>10^5^) leadership-class computing facility simulation campaigns. Users can quickly generate visualizations, animate them through time, manipulate them with a variety of operators and mathematical expressions, and save the resulting images and animations for presentations. VisIt contains a rich set of visualization features to enable users to view a wide variety of data including scalar and vector fields defined on two- and three-dimensional (2D and 3D) structured, adaptive and unstructured meshes. Owing to its customizable plugin design, VisIt is capable of visualizing data from over 120 different scientific data formats (see this [http://www.visitusers.org/index.php?title=Detailed_list_of_file_formats_VisIt_supports partial list]).

== Introduction ==
=== Installation ===
* You can download executables from [https://wci.llnl.gov/simulation/computer-codes/visit/downloads here].
* You can download the source code and compile it. They provides a script that automatically builds VisIt with all dependent libraries.


=== Execution Models ===
==== Stand alone  ====
* Basically, you install VisIt on your desktop (laptop) computer in front of you. And visualize data stored in the file system in your computer.
* If you ran simulations on Cypress, you have to download the results data to the local computer with 'scp' or 'rsync' command.
[[Image(StandAloneVisIt.png)]]

==== Server - Client System ====
 * VisIt is able to visualize data stored in remote computers over the network. 
 * You don't have to download the data into the local computer in order to visualize it.
 * For example:
    * Suppose you ran simulations on Cypress and stored results in the luster file system.
    * Run VisIt on the local computer and choose the remote file system when you open a data file.
    * VisIt program automatically runs on the remote computer and reads the data file.
    * You can work with VisIt as usual on the local computer.
 * Also you can use multiple nodes to render objects in parallel, which allow you to visualize a large data set. 

[[Image(ServerClientVisIt.png)]]

 * You must have same major version of VisIt on both local and remote computers.
 * Run "VisIt" on local machine and go to "Options" -> "Host profiles…" add "cypress2.tulane.edu" like below:
[[Image(Visit host set.png)]]

 * Note that "/share/apps/visit/2.9.2" is where VisIt is installed on cypress. This may be changed in the future.
   * The version is 2.9.2 so you have to use visit 2.9.*.
   * After setup, do not forget to save : Go to "Options" -> "Save Settings".
 * One setup and saved, you don't have do this again.
 * To read data on cypress, "Open" and choose a Host, there must be "cypress2.tulane.edu" on the list.
 * You may be asked typing password every time you read data.