For this pioneering augmented reality installation, a Fresnel lens and semitransparent mirror was mounted on top of a tripod-mounted monitor. The viewer could rotate and tilt monitor and, looking through the mirror, could discover various simple computer-generated virtual objects floating in different locations in the real space in front of them.
The optical method is based on an illusion technique called ‘Pepper’s ghost’, which goes back to the 16th century. It is updated in the Virtual Sculpture by using a video image and a Fresnel lens to change the focal length so that this image appear some meters away when viewed through the semitransparent mirror. The system’s rotate and tilt functions then allow these virtual images to be physically distributed all around the viewer – a virtual reality paradigm inspired by Ivan Sutherland’s ‘Sword of Damocles’ (1968).
The installation used an Apple II computer with its game paddles attached to the monitor to register the tilt and rotation movements. The projected images showed simple, slowly turning wire-frame objects.