VisIt is another open-source, interactive, scalable, visualisation, animation and analysis tool provided for CSCS Users. The data exploration can be done interactively in 3D, with client-server interactive sessions where data are kept locally on CSCS's scratch filesystems, while the GUI and rendering display are sent to remote desktops. Alternatively, the data visualisation can be done programmatically using VisIt’s command-line interface (CLI) with python-driven scripts running on compute nodes.

Licensing Terms and Conditions

VisIt is distributed free of charge with source code.

Setup

VisIt does not use GPUs for accelerated rendering. You should load the daint-mc module on Piz Daint. Should you only have an allocation on the GPU partition, you may also use the daint-gpu module, but be aware that rendering will be software-based. Please load the following on Piz Daint:

module load daint-mc Visit

How to Run on Piz Daint

Batch-mode with Python scripts

The following job script asks for 8 nodes, using 8 MPI task per node. Users will provide their Python code (e.g. file script.py) as an input to Visit.

#!/bin/bash -l
#
# VisIt at CSCS on Piz Daint
#
# 8 nodes, 8 MPI task per node
#
#SBATCH --job-name="VisIt"
#SBATCH --time=01:00:00
#SBATCH --nodes=8
#SBATCH --ntasks=64
#SBATCH --account=<project>
#========================================
# load modules
# Plese uncomment the command specific for the system that you have chosen
## on Piz Daint
# module load daint-mc Visit

srun -n $SLURM_NTASKS -N $SLURM_NNODES -C mc --cpu_bind=sockets visit -nowin -cli -s script.py

Please replace the string <project> with the ID of the active project that will be charged for the allocation.

Interactive mode with a client-server connection

VisIt needs host profiles to connect to a remote locations. The file host_daint.xml must be copied to your private directory $HOME/.visit/hosts, on your desktop.

Opening a parallel server is done with the following steps:

• Select the menu “Open file”, select the name of the host to be “daint”. This will trigger the execution of VisIt’s mdserver on the loggin node. You should then have a listing of your file system
• Select a file to open: a popup menu will let you choose the number of processors and number of nodes for your parallel job. Upon successful connection to a parallel compute server, you may verify its status with the menu "File->Compute engines".