SubComdrTaco writes: A controller developed at Carnegie Mellon University allows computer users to manipulate three-dimensional images and explore virtual environments not only through sight and sound, but by using their sense of touch. It simulates a hand's responses to touch because it relies on a part that floats in a magnetic field rather than on mechanical linkages and cables, according to Ralph L. Hollis, a Carnegie Mellon professor who developed the controller. The controller — like a joystick topped with a block that can be grasped — has just one moving part and rests in a bowl-like structure connected to a computer. Two of the controllers can be used simultaneously to pick up and move virtual objects on a monitor. In a demonstration Tuesday, visitors to Hollis' lab were invited to move an image of a pin across a plate of various textures, causing the controller to bump along ripples, vibrate across fine striations and glide across smooth areas. On one computer, users could "feel" the contours of a virtual rabbit. Hollis said his researchers had built 10 of the devices, six of which were to be sent to other universities across the country and in Canada, and that a new company, Butterfly Haptics, would begin marketing the device in June or July. The controller, which Hollis said will cost "much less" than $50,000, could enable a would-be surgeon to operate on a virtual human organ and sense the texture of tissue or give a designer the feeling of fitting a part into a virtual jet engine, or might also be used to convey the feeling of wind under the wings of unmanned military planes.