A group of eight students ducked and dodged as a stone pendulum swung through the air and then gasped when it harmlessly passed through their bodies.

They were not extras in the latest action movie; they were using the C2 Synthetic Environment, or virtual reality cave as it is commonly called, in Room 1117 of the Black Engineering Building.

These particular students, as part of their freshman honors seminar, toured the Fire Cave C2 application complete with pillars, flames and pendulums.

Chandra Ljunggren, undeclared freshman, said the C2 was better than other virtual reality program she had used because the images were projected onto three walls and the floor.

“It’s an experience you have to go through because you can’t really explain it,” Ljunggren said.

Many people still are unfamiliar with how virtual reality works, but a decade ago it was not even in the popular vernacular, said Jim Bernard, director of the Virtual Reality Applications Center [VRAC] and professor of mechanical engineering.

Now virtual reality is a buzz word all across the country, Bernard said.

Ricardo Menendez, graduate research assistant in the VRAC and graduate student in mechanical engineering, said the process that goes into creating virtual reality worlds such as what Ljunggren experienced is very complex.

To create a virtual reality world, it takes both a computer graphic geometry, or basic design of the environment, as well as a program to make the graphics move in real time with the user, Menendez said.

Because the program is controlled by a hand-held controller, Bernard said the virtual tour of the Fire Cave would never be the exact same.

“The images were created at the moment you saw them; they weren’t stored anywhere,” he said.

Only the geometry, or shape and color, of each part of a virtual reality application is stored in the two large, SGI computers used for the C2, Bernard said.

Public tours are not the only use of the C2, Bernard said. Experiments in which a human is directly involved — such as a flight simulation — are also done.

“In human-in-the-loop research, we study the performance of a human and a machine working together as a system,” he said.

Bernard said these experiments are very beneficial because no one gets hurt in a virtual airplane crash.

Another benefit of humans and computers working together is the combination of strengths, Bernard said. Humans are very good at pattern recognition, and this is perfectly complemented by the computers’ precise memory for applications.

Although computer technology is necessary for C2 to work, people still must write the programs and design the applications for it, Menendez said.

It is this human element that Menendez said draws him to the VRAC.

“Having people from different backgrounds creates a certain synergy,” he said.

Menendez said researchers working in the VRAC have backgrounds from not only engineering, but also art, architecture, computer science, mathematics and statistics.

The VRAC soon will be increasing in size when the $5 million C6 is built in Howe Hall. The C6 will cost significantly more than the $1.2 million C2, and the extra money will bring extra benefits. The C6 will have images projected on all six walls, Bernard said.

“The complete field of view of the C6 allows what we call higher immersion. This means the virtual environments are much more realistic,” he said.

Bernard said having the two centers will present some new opportunities.

“Many of us believe that the next very important application will be cooperation between users in geographically separated virtual environments. The C2/C6 combination will be a great place to support our research in this area,” he said.

Bernard said new uses for the C2 and the C6 will continue to emerge as the technology becomes more common, and he believes ISU is at the forefront of this development.

“We believe we are national leaders in applying virtual reality technology to the challenges of engineering and science. This is a rapidly expanding field of great promise,” Bernard said.

For information on tours of the C2, call Bernard at 294-3092.