Vistle, the VISualization Testing Laboratory for Exascale computing, is an extensible software environment that integrates simulations on supercomputers, post-processing and parallel interactive visualization.
It is under active development at HLRS since 2012 within the European project CRESTA. The objective is to provide a highly scalable successor to COVISE, exploiting data, task and pipeline parallelism in hybrid shared and distributed memory environments with acceleration hardware. Domain decompositions used during simulation can be reused for visualization.
A Vistle work flow consists of several processing modules, each of which is a parallel MPI program that uses OpenMP within nodes. These can be configured graphically or from Python. Shared memory is used for transfering data between modules on a single node.
For rendering in immersive projection systems, Vistle uses OpenCOVER. Visualization parameters can be manipulated from within the virtual environment. Large data sets can be displayed with sort-last parallel rendering and depth compositing. To facilitate access to remote HPC resources, a combination of local and parallel remote rendering is available to decouple interaction from rendering.
The Vistle system is modular and can be extended easily with additional visualization algorithms. Source code is available on GitHub and licensed under the LPGL.
The figure shows an interactive parallel visualization of a pump turbine. The simulation was conducted by IHS.