Virtual reality, that computer-driven replacement for the here and now, may offer a versatile proving ground for police officers and emergency crews training to respond to future terrorist attacks.

Researchers at the University of Missouri-Rolla (UMR) are working to develop just that, an electronic reality replacement that allows emergency personnel more versatility in their training regimes.

"There's been a lot of interest in [virtual reality] because of the national focus on homeland security and concern over future attacks," said Ming Leu, the project's leader and a professor with UMR's department of mechanical and aerospace engineering.

The U.S. Army's Tank-Automotive and Armament Command (TACOM) in Warren, Michigan is funding the two-year, $1 million project.

Virtual reality, or VR, is a completely artificial environment manufactured by computers to give humans the feeling of being somewhere they're not. Although the VR concept dates back to the 1950s, the technique is used widely today due to advancements in human-computer interfaces, three-dimensional imaging software and computer processing power over the last few decades.

The VR approach, for example, is the same tack NASA has taken to prepare astronauts for spacewalks.

"There are already a lot of tools available commercially today for virtual reality research," Leu said. "Enough so that we plan on using off-the-shelf equipment to build our training system."

It's setting up a VR system specifically geared toward terrorist attacks and emergencies that's the tricky part. Leu and his team are currently trying to develop one complete training program, drawing on the July 4 shooting last year, in which a gunman killed two people and wounded three in the ticket area of Los Angeles International Airport before being subdued by officers.

"These kind of events don't happen very often [in the U.S.], thankfully, so you need to draw from past experiences," Leu said.

By simulating a training program in VR rather than using a live exercise, emergency personnel can practice in a controlled environment that allows them to run through a variety of situations in a shorter period of time.

"In physical [live] drills, you can only train for a certain scenario at a time," Leu said. "But in virtual realities you can expand one scenario to include any number of variables."

The program's simulation users will eventually don headgear with goggles and ear pieces, and wear all of the equipment they would normally bring to an emergency situation during an immersion training program. The wireless goggles display stereo images across a user's range of view, while computers track the movements of each trainee and include it in the simulation. Sensors attached to the trainee allow interaction with digital surroundings.

Among the bigger challenges facing the VR training project is the realistic depiction of the movements of trainees and the virtual people they encounter.

"Without the realism, you take away from the entire system's training potential," said Kyle Nebel, a senior mechanical engineer at TACOM specializing in digital human representation." The goal here is to provide first-responders with a realistic training session that doesn't require them to go out and shut down a city block for live exercises."

Since accuracy is key, imperfections in a digital person's movement could distract a VR trainee enough to spoil the lesson. The entertainment and video gaming industries have made great strides in depicting computer-generated humans, but there still remains the task of representing fatigue levels or how much a person could lift during a given operation.

"We look at things like a person's reach and posture, anything that carries the potential for injury in training," Nebel said. "We need to design a system that can mimic these things."

Leu said representing the tools required to detect hazardous materials and other equipment required by emergency personnel has also been difficult, though such obstacles should be overcome during the project's two-year run.

Currently, UMR researchers wear a pair of CrystalEyes glasses as they move about a virtual reality "cave," an enclosure with three walls and a floor onto which the environment is projected.

The polarized glasses work a lot their 3-D movie cousins, separating a pair of overlapping images onscreen into a stereo vision of the virtual world. Four projectors in the "cave," each controlled by a computer, display the VR environment in a 10-foot by 10-foot (3-meter by 3-meter) area.

"Right now you can only run around a little bit," Leu said. "But you can easily set the trainee up on a treadmill if they need to run farther distances."

Leu said that his research group is still evaluating whether the cave approach is preferable to head-mounted VR devices that have their own internal screens and sensors.

A completed training scenario should be ready for testing in the next three months. Once a full program is developed, tweaking it to add variations or generate a completely different simulation will be much easier, Leu added.