The displayed simulations are produced by translating huge quantities of numerical data into three-dimensional images. The system uses top-of-the-line hardware to generate high-quality 3-D OpenGL graphics and "was also the first anywhere to use commodity graphics cards - also used in PCs for high-speed games," Hall says. The laboratory hosts a high-performance computing cluster of 32 dual-Opteron IBM PCs running Linux, interconnected via a low latency Infiniband fabric for data exchange, as well as a Gigabit Ethernet management backbone. The cluster uses ROCKS, an open-source cluster management system, for administration and job management. The Visualization Centre uses four high-end IBM workstations to display data. One of them, called the application node, runs the visualization application, such as Landmark's GeoProbe, GoCAD or UCSF's Chimera. The graphical, OpenGL-based output is processed by a lower software layer running on the application node, which distributes the graphics to three other workstations, called rendering nodes. This layer runs the open-source Distributed Multihead X system (Xdmx) or IBM's proprietary Deep Computing and Visualization environment (DCV), depending on the performance level required by the higher level application being run. Both Xdmx and DCV intercept the graphics generated on the application node, split them in three vertical bands and direct each band to the X server Behind the screen, images are rear-projected onto mirrors which reflect the that runs on the appropriate rendering images forwards onto the transmissive screen node. Xdmx creates a virtual desktop across all three rendering nodes and sends the X11-based graphics accordingly. DCV, on the other hand, significantly enhances performance by splitting the graphics stream at a lower level (OpenGL primitives), thus avoiding the well-known performance issues of remote X11-based graphics. Another option for the budget-minded user can be the open-source package Chromium, which provides the necessary functionality at a similar performance level, free of charge. Chromium has the advantage of being available for both Linux and Windows-based application nodes (called "motherships" in Chromium nomenclature), which can significantly expand the range of possible applications. All four workstations are interconnected via an Infiniband
34 MTR October 2007
The research center opened in 2005 as the only one in Atlantic Canada and among very few such facilities worldwide, and brought together high-performance computing and immersive, 3-D visualization. The Landmark Graphics Visualization Laboratory is actually an immersive 4-D facility -- three spatial dimensions plus a temporal one -- allowing researchers to view a structure over time as well. The laboratory seats 22 people, allowing groups to collaborate on research and development projects, using mono or active stereo applications. The focal point of the lab is a 22 feet wide by 7 feet high cylindrical screen. The screen is curved so it completely fills your peripheral vision, and the facility uses a rear-projection system to allow researchers to interact in front of the screen without casting shadows. "This allows a group of people to stand in front of it and look at the detail of an oilfield," Hall says. "And that's enormously useful when you're trying to work out how best to produce from a well." Using three rear-mounted projectors in a confined space, (See picture below) MUN could not use a regular reflective screen as used in movie theatres. Instead, images are projected from behind the screen onto mirrors which then reflect the image forwards onto the back of a transmissive screen.
You don't have Macromedia Flash Player installed.
This content requires the Macromedia Flash Player.
Get Flash
www.digitalwavepublishing.com
www.MarineLink.com