| | 1 | [[PageOutline]] |
| | 2 | = VisIt = |
| | 3 | https://wci.llnl.gov/simulation/computer-codes/visit/ Visit Home Page] |
| | 4 | |
| | 5 | 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]). |
| | 6 | |
| | 7 | == Introduction == |
| | 8 | === Installation === |
| | 9 | * You can download executables from [https://wci.llnl.gov/simulation/computer-codes/visit/downloads here]. |
| | 10 | * You can download the source code and compile it. They provides a script that automatically builds VisIt with all dependent libraries. |
| | 11 | |
| | 12 | |
| | 13 | == Execution Models == |
| | 14 | === Stand alone === |
| | 15 | * Basically, you install VisIt on your desktop (laptop) computer in front of you. And visualize data stored in the file system in your computer. |
| | 16 | * If you ran simulations on Cypress, you have to download the results data to the local computer with 'scp' or 'rsync' command. |
| | 17 | [[Image(StandAloneVisIt.png)]] |
| | 18 | |
| | 19 | === Server - Client System === |
| | 20 | * VisIt is able to visualize data stored in remote computers over the network. |
| | 21 | * You don't have to download the data into the local computer in order to visualize it. |
| | 22 | * For example: |
| | 23 | * Suppose you ran simulations on Cypress and stored results in the luster file system. |
| | 24 | * Run VisIt on the local computer and choose the remote file system when you open a data file. |
| | 25 | * VisIt program automatically runs on the remote computer and reads the data file. |
| | 26 | * You can work with VisIt as usual on the local computer. |
| | 27 | * Also you can use multiple nodes to render objects in parallel, which allow you to visualize a large data set. |
| | 28 | |
| | 29 | [[Image(ServerClientVisIt.png)]] |
| | 30 | |
| | 31 | * You must have same major version of VisIt on both local and remote computers. |
| | 32 | * Run "VisIt" on local machine and go to "Options" -> "Host profiles…" |
| | 33 | * Click [New Host] and edit like below: |
| | 34 | * Set ''Host nickname'' as you like. |
| | 35 | * ''Remote host name'' must be "cypress1.tulane.edu" or "cypress2.tulane.edu". |
| | 36 | * Set Path to visit installation. |
| | 37 | * Note that "/share/apps/visit/2.9.2" is where VisIt is installed on cypress. This may be changed in the future. Use "module avail" command to see which version is available on cypress. |
| | 38 | * The current version is 2.9.2 so you have to use visit 2.9.* on local machine. |
| | 39 | * Set ''Username''. This is your login ID for Cypress. |
| | 40 | * Check on ''Tunnel data connection through SSH'' |
| | 41 | * Click [Apply]. |
| | 42 | [[Image(VisItCypress1.png, 50%)]] |
| | 43 | |
| | 44 | |
| | 45 | ==== Serial Rendering ==== |
| | 46 | This set up VisIt to render objects with one process. |
| | 47 | * Select on [Launch Profile] tab. |
| | 48 | * Click [New Profile] and select [Setting] tab. Give a name on ''Profile name''. |
| | 49 | * Select [Parallel] tab and check ''Launch parallel engine''. |
| | 50 | * Select [Launch] tab and set '''srun''' on ''Parallel launch method''. |
| | 51 | * Set Numbers of processors and nodes 1. |
| | 52 | * Click [Apply]. |
| | 53 | [[Image(VisItCypressSerial.png, 50%)]] |
| | 54 | * After setup, do not forget to save : Go to "Options" -> "Save Settings". |
| | 55 | * Once setup and saved, you don't have do this again. |
| | 56 | |
| | 57 | ==== Parallel Rendering ==== |
| | 58 | This set up VisIt to render objects with multiple processes on multiple nodes. |
| | 59 | * Select on [Launch Profile] tab. |
| | 60 | * Click [New Profile] and select [Setting] tab. Give a name on ''Profile name''. |
| | 61 | * Select [Parallel] tab and check ''Launch parallel engine''. |
| | 62 | * Select [Launch] tab and set '''sbatch/mpirun''' on ''Parallel launch method''. |
| | 63 | * Set Number of processors, this is the total processors. |
| | 64 | * Set Number of nodes. |
| | 65 | * The example below sets Number of processors is 20 and Number of nodes is 2. This will use 2 nodes and 20 processes in total; 10 processes for each node. |
| | 66 | [[Image(VisItCypressParallel1.png, 50%)]] |
| | 67 | * Select [Advanced] tab. |
| | 68 | * Check ''Launcher arguments''. This is the parameters for SLURM queuing system. |
| | 69 | * In the example below, requesting 64G of RAM and 10 tasks (processes) per node. |
| | 70 | * Check ''Sublauncher pre-mpi command'' and set '''module load intel-psxe/2015-update1 visit'''. This is important to launch MPI tasks. |
| | 71 | [[Image(VisItCypressParallel2.png, 50%)]] |
| | 72 | |
| | 73 | * After setup, do not forget to save : Go to "Options" -> "Save Settings". |
| | 74 | * Once setup and saved, you don't have do this again. |
| | 75 | |
| | 76 | * To read data on cypress, "Open" and choose a Host, there must be "cypress" on the list. |
| | 77 | * You may be asked typing password every time you read data if you haven't set up passwordless ssh login. |
