Until we all have Star Trek-like holodecks at home, there's not much economy of scale in manufacturing equipment for room-sized virtual environments like the CAVE and CUBE at the University of Illinois' Beckman Institute.
Which is why the specialized wireless handheld controller people used to reach into and navigate the virtual worlds projected in the rooms – on three sides in the case of the CAVE and completely surrounding them in the CUBE – cost $60,000.
And as much as $15,000 to repair if somebody dropped it too hard.
Then Henry Kaczmarski, generally known as Hank, who runs the facilities as director of Beckman's Integrated Systems Lab, started to notice a trend, as did some of his colleagues at the lab.
"We would give this to people," Kaczmarski said recently, referring to the expensive custom controller, "and they would say: 'That's like a Wii, isn't it?'"
Nintendo's mega-popular Wii game console – just try getting one even months after the holiday gift-giving rush – also employs a wireless controller, the Wii Remote, or "Wiimote."
The Wiimote and the related "Nunchuk" accessory that plugs into it are able to sense movement and acceleration, among other things, the better to smack one out of the park in a Wii baseball game or guide running, jumping Super Mario through the latest course of obstacles confronting him.
The Wii's wireless motion-driven controller, which also includes the usual array of buttons and directional pads common to game controllers in general, is a big reason for its hit status, despite the fact that competitors like the PlayStation 3 and Xbox 360 offer quite a bit more in computing horsepower and graphical detail.
The Wiimote's capabilities also happen to make it a lot like the pricey controller the Beckman lab used.
Except that the Wiimote costs $40. Unlike the Wii console itself, Wii controllers can be had pretty much by the bushel, off the shelf at almost any electronics store or department.
Jim Crowell and Camille Goudeseune, computer programmers at the UI lab, set out to re-purpose the Wii controller for use there.
"As things go, this was not a very hard one," said Crowell, who also is a cognitive psychologist.
Open source drivers, free software whose underlying code is ready-made to access and modify, already existed for letting the Wiimote communicate with standard personal computers, so it wasn't a big stretch to get it to talk to the computers behind the CAVE, the CUBE and other virtual environments used by the lab, Crowell and Goudeseune said.
The controller has other advantages, like employing the standard Bluetooth method of connecting wirelessly, the same thing used to connect wireless headsets and cell phones, for example.
Goudeseune said that also makes it easy to connect the Wiimote to Bluetooth-equipped PCs, as many laptops are in particular, where programming can be done without having to tie up the lab's virtual environments in the process.
The upshot is that people are now using Wii controllers to fly through a heart or a DNA molecule, spear fish and navigate a maze by dead reckoning or the environs of a nuclear power plant, which are among the programs the lab has working with the Wiimote to date.
Besides cost, Goudeseune said there's another advantage to using the Wii controllers. Thanks to the Wii's popularity, people handed a Wiimote generally don't need much explanation to start using it in the CAVE, CUBE, or elsewhere.
"They know that they're supposed to move it different directions," he said. "It's a cultural familiarity."
"There's no learning curve because everybody knows a Wii," Kaczmarski said.