Virtual Reality, as we know it today, consists of head-mounted displays, with detailed stereoscopic 3D imagery, audio cues, motion tracking, and perhaps most important is that many current VR machines are portable. However, the predecessors of current virtual reality machines were more expensive, heavier, larger, and not that portable. This is not a comprehensive list of all of the history surrounding virtual reality but it does cover some of the important pieces of VR history.
Sensorama (mid 1950s)
In the mid 1950s Morton Heilig, a cinematographer, developed what was called an the Sensorama, an arcade-style theater cabinet that would stimulate all the senses, not just sight and sound. Many timelines have the Sensorama as being invented in 1962 but it was created before during the 50s and only patented in 1962. Heilig created a machine that could display stereoscopic 3D images in a wide-angle (wide vision) view, move in accordance with the picture being shown, create wind, and create aromas that were triggered during the film. The intended purpose of all of these different stimuli was to fully immerse the viewer in a film. Heilig would later try to expand on his Sensorama by creating what he called an 'Experience Theater'. This theater was simply a Sensorama for a larger audience and made use of the same technology that was inside the Sensorama. Although his idea and design were patented in 1969 it was never constructed in the real world.
Telesphere Mask (1960)
The Telesphere was the first example of a head-mounted display (HMD). It was designed by Morton Heilig and was used for showing non-interactive films without any motion tracking. Although this particular device was not used as a true VR headset it helped to pave the way for today's current VR headsets. Similarities between today's modern headsets and Heilig's Telesphere Maskcan be seen when looking at its design characteristics.
Headsight (1961)
In 1961, Comeau and Bryan, two Philco engineers created what would be the first physical head-mounted display (HMD) with motion-tracking. The Headsight was the first controllable electronic VR experience as it incorporated a video screen and a basic magnetic head tracking system into a helmet. The magnetic tracking system allowed the user to remotely control a camera which simulated movement of the picture or video feed. The video screen and tracking system were both linked to a closed-circuit television (CCTV). The Headsight was mostly used in the military as it allowed users to remotely view situations that they were not able to view otherwise.
Sword of Damocles (1968)
The Sword of Damocles was the first VR head-mounted display that was connected to a computer. All previous iterations of VR headsets were connected to some sort of camera. Ivan Sutherland and Bob Sproull created this large and somewhat scary looking piece of machinery. Because of the technology available when it was built, the Sword of Damocles was far too heavy for a user to wear without external (ceiling) support. In addition to its significant weight, the computer generated graphics that were displayed consisted of very primitive wire-frame rooms and objects.
VideoPlace (1985)
In 1969 Myron Kruegere a virtual reality computer artist developed a series of experiences which he referred to as 'artificial reality'. These experiences were computer-generated environments that responded to the people in it. The projects or experiences that he created were called Glowflow, Metaplay, and Psychic Space. All of these ideas came together in the 1970s when he introduced his Videoplace technology. After he showed Videoplace to the public Myron combined what he had learned and went on to create artificial reality laboratories which made use of his technology.
Virtuality Group Arcade Machines (1991)
Virtuality was a line of virtual reality gaming machines produced by the Virtuality Group. These VR stations were found in video arcades in the early 1990s. They delivered real time gaming via a stereoscopic headset which had two liquid crystal displays (LCD), free moving controller/joystick, and networked units for multi-player games. Each unit also had four speakers and one microphone attached to it to increase immersion. There were two types of virtuality units or 'pods' as the company called them. One type of unit was created for the user to stand up when playing a game and the other type unit was created for the user to sit down when playing a game.
SEGA VR (1993)
The Sega VR was a virtual reality headset that was created in the early 90s. It was an adaptation of a similar headset that Sega was using for arcades but this device was marketed as a portable home gaming system. The headset itself, an HMD, was outfitted with LCD screens in the visor coupled with stereo headphones. The way it captured motion was due to inertial sensors in the headset. Marketed at $200 the final produce never saw a public release because of development difficulties with included causing motion sickness and severe headaches in users.
Virtual Boy (1995)
In 1995, Nintendo released the Virtual Boy which was marketed as the first console capable of displaying stereoscopic 3D. Stereoscopic refers to a pair of stereo (two) images which, when viewed through a specific medium (in this case a head mounted display, combined to give the brain the illusion of 3D depth. The Virtual Boy did not see a long shelf life as it was only available in the U.S. for seven months before it was discontinued. This was due to its high price, at $179.95 per unit, monochrome display (red and black images), unimpressive 3D effect, lack of true portability, health concerns (there was a high number of people that complained of head/eye pain with prolonged use, low quality of games, and marketing campaign.
Google Cardboard (2014)
Oculus Rift, HTC Vive, Playstation VR (2016)
The main difference between the current iteration of virtual reality headsets such as the Oculus Rift, THC Vice and Playstation VR as opposed to VR headsets of the past the amount of portability that current headsets are able to have. This is in part due to the advancement of technology creating smaller, lighter parts. Most current VR machines use an HDMI cable that connects a console or computer to the headset. The information (image, video, game, etc.) is then displayed on the stereoscopic LCD screens inside the headset. The stereoscopic aspect of the headset is still the same as it was many years ago, the LCD images are combined using the lenses inside the headset to give the user a perception of depth. One of the more advanced aspects can be seen when using the motion-tracking system which make use of a 6DoF plot as well as internal gyroscopes, accelerometers, and magnetometers. 6DoF refers to six degrees of freedom which helps when plotting a user's head on the X, Y, and Z axis.