By virtue of the tracking armature suspended from the ceiling and attached to the display, transformations could be calculated and the view of the wireframe images updated to reflect these physical changes of viewpoints.
Figure 1.8 This image shows the head-mounted display developed by Bell Helicopter and used by computer scientist Ivan Sutherland and students to conduct early augmented and virtual reality research.
Parallel to Sutherland´s work in the 1960s and 1970s in civilian research labs, the U.S. Air Force was involved in its own development efforts. Of particular note was work carried out at Wright-Patterson Air Force Base in Ohio under the direction of Dr. Thomas Furness. One of these projects focused on development of virtual interfaces for flight control. In 1982, Furness demonstrated a system known as VCASS (Visually Coupled Airborne Systems Simulator) shown in Figure 1.9.
Figure 1.9 The image on the left shows an engineer wearing the U.S. Air Force Visually Coupled Airborne Systems Simulator (VCASS) helmet while seated in a laboratory cockpit (circa 1982). The terrain scene, symbology, and avionics data on the right are representative of the imagery displayed to the user.
The VCASS system used high-resolution CRTs to display visual information such as computer-generated 3D maps, sensor imagery, and avionics data to the simulator operator. The helmet´s tracking system, voice-actuated controls, and other sensors enabled the pilot to operate the aircraft simulator with gestures, utterances, and eye movements, translating immersion in a data-filled virtual space into control modalities (Lowood, 2016).
Between these early systems and today, a multitude of fully immersive stereoscopic head-mounted displays have been developed, albeit a majority for the high-end simulation and training market.