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Data pictures - ORNL's visualization facility generating images big and small
By Sharon Pound
Walk into the new visualization facility at the Oak Ridge National Laboratory, and you’ll see computer-generated graphics that measure a massive 8 feet by 30 feet.
The images might depict something as small as a nanometer, which is a tiny one-billionth of a meter. Or the images might depict something as large as the birth of an entire new solar system. The time frames for these phenomena might be a trillionth of a second, known as picoseconds, or they could be hundreds of years.
The visualization team at ORNL is charged with taking scientists’ massive volumes of data and then relating that data visually in meaningful ways, explains Dr. George Fann, acting team leader.
He lists a variety of images that have already been generated, including the patterns of peroxide and helium molecules as they move through carbon nanotubes and 3D images of a mouse skeletal structure constructed by using an isosurface imaging technique built from “stacks” of two-dimensional images. Another dramatic image shows 20 years of climatic activity across the entire globe.
It was generated in a biogeochemistry project between Los Alamos National Laboratory and ORNL and is based on a simulation of the ocean ecosystems and circulation.
"We’re no longer dealing with reams of papers as we understand science," Fann explains. "Instead, we’re generating big, 3D, time-dependent images of results from computer simulations. And in the process, we’re helping scientists test hypotheses, better understand data and make new discoveries."
For example, Ross Toedte, a visualization expert, explains that prior to visualizing the data related to core-collapse nova, scientists thought the continuing expansions of stellar explosions were caused by alternating pulses of material in opposite directions.
Through visualization of three-dimensional simulation data, it became obvious that the expansion was more complex and occurred at multiple rather than two locations.
"The scientists went back to their equations for further analysis and exploration," Toedte says. The facility is the showcase of ORNL’s visualization laboratory, which also researches a variety of visual display technologies, including high-resolution monitors and various panel displays, including a four-walled immersive room environment.
Other members of the visualization team are Dr. Jim Kohl, Stewart Dickson and Jamison Daniel.
"Our team works with the scientists by initially asking questions, such as what do they already know, what do they want to know, what form is the current data in, and how big is the data set," Toedte explains.
Then, the scientists and computer graphics experts consider the best option to depict the data. Their system has been developed in preparation for the world’s most powerful open science computer that will be built at the National Leadership Computing Facility at the Center for Computational Sciences.
The visualization lab’s computer system uses 100 processors to analyze the results of mathematical and scientific calculations. The massive display is generated by 27 projectors run by a cluster of 15 computers, with an aggregate capacity of 32 processors, 44 gigabytes of memory, high-end graphics cards and five terabytes of disk space.
The result is an image that totals 35 million pixels, Fann concludes, which is much higher resolution than the typical HDTV picture with just over two million pixels.
"These graphics deliver one more way for scientists to explore their hypotheses that was never available before," Toedte says. "We’re able to use tremendous computing resources to simulate what they think is happening."
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