The particle sampler coupled to the simulation, the daemon running on the interactive node, and the PBVR client on the user's PC work together to provide interactive visualization of the simulation being processed. In order to achieve this, some simple configuration and port forward connections are required.

The daemon and particle sampler use the following environment variables, and you need to set them with the export command at runtime.

Environment Variable Name	Description
VIS_PARAM_DIR	Directory where transfer function files (visualization parameters) are placed*1
PARTICLE_DIR	Directory where the pseudo-simulation code outputs particle data*1
TF_NAME	Transfer function file name (not including extension)*2

*1 If not specified, the daemon and particle sampler search the current directory in which they are executed.
*2 Unless specified, daemons and particle samplers use default.tf as the transfer function name.

When the particle sampler converts the volume data of the simulation result into particle data for visualization, visualization parameters such as the transfer function, the range of the physical value to be visualized, and the screen resolution are required. Visualization parameters are tag-based in the transfer function file. The user can use the default.tf stored in the example of the source package as a transfer function file at the time of first startup. In order to run In-Situ PBVR, the user must place the transfer function file in the directory specified by the environment variable VIS_PARAM_DIR with the file name specified by TF_NAME. The user can edit the contents of the transfer function file through the GUI by launching the daemon and PBVR client. The transfer function file specified by the environment variable is read by the daemon, displayed on the PBVR client, edited, and overwritten.