University of California, Irvine
HIPerWall: New Vistas in Scientific Visualization
In this simulation, the full resolution images of the Gulf Coast before and after Hurricane Katrina occupy the entire 200-megapixel HIPerWall display. A zoom window overlays the 20 panels on the left side to show the level of detail available in the Terraserver images.
Even with the team's confidence and experience, the Apple platform exceeded its expectations and its development time was in fact reduced by the plug-and-play compatibility of the hardware components, which eliminated the need to do low-level hardware integration in-house. This freed up the HIPerWall team to focus on three major design challenges:
1. Tiled display challenges: These include physical issues such as the racking, mounting, and interconnection of the display and computing resources, and middleware issues related to the acquisition and presentation of each tile’s appropriate portion of the overall image space. The design needed to anticipate future enhancements for different scientific visualization and human computer interaction techniques and the possible addition of displays around and above the viewer to create an immersive environment.
“You should be able to come in and work on your own project with the system configured optimally for you. That’s something that’s actually quite unique to what HIPerWall facilitates now.”
“Our team had plenty of experience running various operating systems on various processors,” says Dr. Stephen Jenks, a principal investigator on the HIPerWall project. “So we were confident we could handle any of the likely scenarios when it came to matching the computer/render and display components of the system.”
The performance and integration of the Power Mac’s graphics subsystems, including OpenGL and Quartz Extreme, contributed to the overall performance of HIPerWall and facilitated rapid development of the middleware.
2. Data processing and transport challenges: These include questions about where and how to execute the image creation, rendering, and display functions and how to manage the transfer of information between the HIPerWall and various remote computing and storage assets. The team’s collaboration with another Calit2 project named OptIPuter, a high speed optical network to interconnect supercomputing clusters addresses the latter issue. The HIPerWall architecture recognizes situations where the image originates at a remote supercomputer or SAN. The image is then routed to a separate render farm using this optical network and finally to the HIPerWall for display and user interaction.
For image creation, the Mac is designed to offload most image processing tasks from the dual G5 processor directly to the graphics card for optimal performance and to free the G5 to handle rendering or data processing tasks.
3. System administration challenges: Tiled displays driven by multiple computers present a number of challenges to the administrator, not the least of which is the time it takes to initialize and configure all of the subsystems. The Apple Remote Desktop system management application made the configuration and administration extremely straightforward by allowing the system administrator to control all 25 Power Mac G5 systems using one master system. The HIPerWall team also used Apple Remote Desktop in conjunction with AppleScript, the system-level scripting language in Mac OS X, to create a one-click login process that automatically configures the HIPerWall for each user.
“It’s a challenge to control and administer multi-tile systems,” Kuester says. “In the past, the popular technique was to use a UNIX- or Linux-based system, log in to all of the render nodes as root, and never touch the system again until something broke or you needed to reconfigure the system.”
That approach was not suitable for the HIPerWall research environment which needed to accommodate multiple users, projects, and display configurations as well as address the security concerns of the host institution.
“You should be able to come in and work on your own project with the system configured optimally for you,” Kuester continues. “That’s something that’s actually quite unique to what HIPerWall facilitates now. We are able to bring the system up, fully configured for a new user, with a single mouse-click.”