LESSON 2 - HISTORY OF VIRTUAL REALITY
The history of virtual reality has largely been a history of attempts to make an experience more real. The majority of historical examples are visual and to a lesser extent, auditory. This is because of all the human senses, vision provides by far the most information followed by hearing. Probably 90 per cent of our perception of the world is visual or auditory.
The earliest attempts to capture reality would include the cave paintings mentioned above. A contemporary person looking at these painting would not be impressed by their realism. However, in the setting in which they originally appeared, there were no other representations of reality for comparison. The only thing to which the viewer could compare the picture was his own memory. The paintings perhaps did not even provide the detail and realism of a memory; however, the painting could serve as a stimulus to trigger the memory and fill in details which might not otherwise have been noticed. Also paintings do not fade over time as the vividness of a memory does.
The paintings were not necessarily used alone, but may have been used along with hunting chants. Illumination was provided by flames. Such unsteady and uncertain lighting can serve to isolate the fact that the scene is painted on a wall and allow the user to move the scene into the uncertain and unsteady light of an early morning hunt. Hunting songs and chants bring back and strengthen memories of past hunts. Cave paintings are more of a "multi-media" event than is commonly thought.
All of the clues used to provide realism with these paintings are just that: clues. It is necessary that the viewer have participated in an actual hunt before these visual and auditory clues can bring forth the remembered sensations. These clues bring back an actual experience and provide, perhaps, the most "real" virtual experience. However, the viewing audience is limited to those who have already had a similar experience.
As history progressed, painting progressed along with it. Artists developed techniques of perspective to help their paintings appear more lifelike. New methods of depicting light and shadow were created. Methods of presenting objects with a three dimensional look were discovered. All of these methods helped the viewer to better "believe" in this artificial world. They still relied on the knowledge of the viewer, but the knowledge no longer had to be of direct experience. A viewer who had never left Europe could still relate to a round African hut. For although he had never actually seen such a hut, he was familiar with other types of houses and the representation within the picture was such that he could extrapolate from what he had seen to what was depicted. Thus no longer was the picture simply making the viewer recall an actual experience, but was using his knowledge base of similar items to provide a new experience. Painting technique has continued to progress in the direction of realistic and accurate representation.
Along with two dimensional paintings, men also developed and improved sculpture to provide three dimensional representation. This also progressed in the direction of realistic representation. (It should also be noted that sculpture can provide a tactile sense input as well as accurate 3-D viewing.)
The sense of hearing was not forgotten during this time. Hunting chants as well as animal calls and other sound effects have been produced by story tellers since the earliest of times. However, until the advent of sound recording in the late 1800s, sound reproduction was limited to what could be produced by the human voice or by various instruments. It should be noted that sound reproduction is not the only audio effect which can enhance the realism of a world. Background music has been used to create a mood or feeling or even to convey information for a long time.
Another area of audio effect used since before recorded time is spoken language. Early histories were spoken records committed to memory. Early Celt tribes always had a bard present to record battles or other important events. This was such an important function that the bard held one of the highest rankings within a tribe and was considered an untouchable non-combatant during any battle. His work included far more than the straight forward recording of facts. By use of language and expression the bard did much to recreate the people, places, and events he recorded. A virtual world was created for his listeners.
Written language produced probably the most realistic of the virtual worlds. A good novel can involve the reader to the extent that he becomes "lost" in the story and both the settings and characters become "real". This is not a "virtual reality" in the way we usually use the term because no sensory input is provided. The reader creates the entire world in his own mind. But the use of language descriptive clues can be considered for inclusion in a virtual world along with material directly for the senses. For example, a sign hanging in a visual presentation can convey anything from direct information (i.e., SHOE STORE) to a mood (i.e., J.S. + G.R. on a tree trunk) to an implied history (i.e., HOME FROM THE SEA on a tombstone). This mix of media is not new: consider the use of illustrations with a novel.
Another mix of media was used with the panorama paintings 
described in the
text. Here a picture was painted which surrounded the viewer in a large circle. Real
objects were placed in front of the picture and blended into the painting. This technique
has been used by Hollywood for nearly a century where much action is filmed on a sound
stage using a backdrop. Real props are often "extended" into the background
painting.
In the mid 1800s photography was invented. This was a change in kind rather than a simple improvement in the presentation of visual scenes. Now actual sights could be recorded, rather than recreated by an artist. Not only could photographs capture more detail than an artist but they were not subject to his - knowing or otherwise-interpretations. While these picture were in black and white only, and while their quality was far below what we expect today even from the most inexpensive camera, they enabled people to "see" for themselves things which were distant in space and time. In fact the places and people viewed had to be removed in time because the photographic process required time. Photographs could show real worlds even if not in real time.
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Daguerreotype Images
Dorling Kindersley |
Another invention of the late 1800s which was to improve the realism
of virtual
worlds
was the recording of sound. Edison’s phonograph did for
audio what the camera did for the visual sense. To some extent this was even a bigger
advance towards realism than was the photograph. To understand what is meant by this you
must remember that an artist could copy a real scene. Perhaps it wasn’t as detailed
as a photograph and perhaps it could be distorted by the artist’s interest or
prejudice, but it did provide the viewer with a copy of the real world. An audio event -
speech, etc. - could only be copied by having another person reproduce it in his own
voice. Much in the way of exact wording, inflection, and volume was lost. The invention of
sound recording meant that a listener in another place and time could hear the words of
the speaker in his own voice. Additional non-vocal sounds could be recorded which
previously could only be described.
Although there were constant improvements in both visual and audio presentation for many hundreds of years, it was only a little over a century ago that there was made the first really significant advance in creating an artificial world in which the average viewer could become totally immersed: adding motion.
Prior to Edison’s invention of motion pictures in the late 1800s, the only method of adding any sense of time to a picture was to use a sequence of still scenes, such as Muybridge used to show that a horse can have all four feet off the ground at once, which followed each other in chronological order. While a single view can deeply involve the viewer in its virtual world, the time factor is necessary in portraying a story.
The human eye can distinguish two events if they are separated by more than about one tenth of a second. If they are closer together than this the mind interprets them as a continuous happening rather than a distinct sequence. For example, a light that flashes at a rate higher than 10 times per second appears to be constantly on. To provide a clear sense of motion rather than a jerky appearance, a rate of 20 to 30 events per second is used. Television, for example, presents 30 separate pictures, or frames, per second. To the viewer the result is smooth, continuous motion.
The motion picture consists of a series of still photographs taken - and later shown - at a rate which is typically 24 frames per second. Early films and especially early home movies used a slower rate resulting in a jerky motion when shown. Early movies, of course, had only visual recording capability. There could be no dialogue or sound effects. Information which should be imparted verbally required printed language.
Still, the sense of motion, added to the detailed, accurate visual presentation, allowed the viewer to become much more immersed in a story. Almost as an expedient the movie industry began to experiment with methods of creating actual photographs of places and events which were not real. Model ships could be sailed in a pool, burned and sunk at a much lower cost and with a greater degree of safety to the people involved than if the real thing were used. It was not necessary to travel to Paris to film a story if the appearance of the city could be produced with paintings, models, and lighting. This marks the beginning of the major business of creating virtual worlds.
Over the next century the quality of the film process continued to be improved. Technical advances yielded finer grain films with higher resolutions. Faster cameras removed the shaky, jerky quality of the early movies. Color made the photographs more life-like. Sound was added in a synchronized fashion to the visual presentation.
In addition to the advances in technology, Hollywood learned better techniques for using models, retouching film, and mixing still photos and paintings with live action. Special effects allowed many conditions to be duplicated on film without having to actually exist. In short, the technique of creating a virtual world in which the viewer could be immersed advanced.
Many techniques were tried to increase not only the realistic portrayal of scenes and events shown on the screen, but also to reduce the viewer’s awareness that he was watching a movie and not the actual event. One large drawback was that the movie screen occupied only a small portion of the viewer’s actual field of view. A look to the right or left or up or down immediately destroyed the illusion of being a part of the action. In the 1950s the Cinerama technique was developed. This utilized three synchronized cameras set a three different angles horizontally to capture the action. The movie was then shown on three curved screens by three projectors. The screens used were also much higher than standard movie screens. Additionally a large format film was used to increase resolution. The result was that the viewer could have a view of nearly 180 degrees. Six-track stereo sound added to the realism. These movies, although very expensive to produce, did provide a sense of realism which drew audiences to theaters in record numbers. At its height 100 theaters were equipped to show Cinerama films. Today one remains.
Another 1950s attempt to improve realism involved 3-D films. Three dimensional pictures had been produced in still format for some time. The stereoscopic viewer dated from the mid 1800s. In this device two pictures were taken of the same scene from points separated by a couple of inches (as are the human eyes). The viewing device consisted of two lens systems which displayed the two pictures to the two different eyes. The result was a very realistic three dimensional view. Early stereopticon slides were, of course, black and white. In the Twentieth Century an advanced form of this system, called the Viewmaster, was produced. In this device pairs of 8mm color slides were placed on a disk which went into the viewing device. The user again looked through two different eyepieces to see a 3-D, full color picture. The disk could be rotated by the user to display eight sets of slides.
In the mid 1950s 3-D comic books and 3-D movies were produced using a different technique. The Viewmaster method required the user to employ a restrictive device to limit the view of each eye. The use of such a device would interfere with the viewing of a movie. The technique employed was to film two copies of the scenes with the two spaced cameras in the same way as was done for the Viewmaster slides. However, instead of filming in full color, one side was filmed in red and the other in green. These two images were then combined into a single film and projected on a screen. The viewer wore a special pair of glasses with one lens red and the other green. Thus one image was delivered to each eye and produced a reasonable imitation of a three dimensional movie.
Another interesting attempt at a realistic experience was the Sensorama system designed
in the late
1950s and early 1960s. In this system the participant sat near a small binocular-like
viewer in a booth-like device equipped with handlebars and a motion seat. Sound was
supplied from stereo speakers mounted near the ears. Vents could provide air motion and
even smells associated with the scene being shown. These devices, although never produced
commercially because of cost, provided a very realistic experience. With the wide variety
of sensory inputs they could allow the user to become very immersed in the virtual world.
They did, however, lack the ability for the user to interact with the virtual world. This
ability would have to wait for the development of high speed, high power computers.