The HECToR Service is now closed and has been superceded by ARCHER.

Massive Remote Batch Visualizer

Porting AVS/Express to HECToR

This Distributed Computational Science and Engineering (dCSE) project has ported the AVS/Express Distributed Data Renderer visualization application to HECToR (Cray XT4 Phase2a). This allows the visualization of datasets that are too large to visualize using GPU hardware. Initially our target end users are Materials Scientists that wish to examine volume datasets acquired through CT X-Ray scanning techniques. AVS/Express is not, however, limited to this form of data and so can be used in other research areas.

AVS/Express DDR provides parallel module processing, where various visualization techniques are applied to domain decomposed data. Parallel rendering and image compositing, utilizing the distributed memory available on HECToR, allows significantly larger datasets to be visualized. Initially a batch rendering system was proposed. However, modifications to the AVS code allow interactive use of the application on HECToR. The main development work includes:

  • Development of a replacement MPI library for the AVS/Express user interface code. This allows it to forward MPI function calls from a login node (on which the UI code must execute) through a proxy running on a back end node and enables the existing AVS parallel module architecture to be used for module development without the need to introduce another communication API. Custom AVS applications can then be developed where a user interface is required for interactive use.
  • A parallel image compositing method using MPI has been implemented to replace the sockets-based code in AVS/Express.
  • Improvements to the AVS rendering code allow interactive use of the application with many more processors than any previous installation of the product. Volumes of sizes up to approximately 7k3 have been rendered.

Please see PDF or HTML for a report which summarises this project.