Steering and Visualization of Electro-Magnetic Simulations Using the Globus Implementation of a Computational Grid

A framework for computational steering of a finite difference code for electromagnetic simulation has been developed and implemented. In computational steering we need to develop software which allows the user to enter an interactive visualization or VR environment and from there control the computation. A proof of concept implementation has been carried out using an existing code for 3D finite difference time domain approximation of Maxwell’s equations. Large parts of the computational steering software are general but details in the choice of control variables and visualization is specialized to the electromagnetics code. To handle the large computational requirements of both simulation and visualization the system can be distributed across multiple machines. This is possible through the use of the Globus toolkit for communication, data handling, and resource coallocation. It program also makes use of VTK for data filtering and the generation of visualization elements, and IRIS Performer with pfCAVELib for 3D interactive rendering on CAVE compatible devices. Two testcases are presented. In one example with a smaller number of computational cells, full computational steering with recomputation is possible. In another with a large number of computational cells the solution is precomputed and only the visualization is interactive. The scalability of the computational code is tested for different computers in order to determine the size of the problem which can be handled with full computational steering on the available local hardware.