How did we arrive to VR as it exists today? We start with a history that predates what most people would consider to be VR, but includes many aspects crucial to VR that have been among us for tens of thousands of years. Long ago, our ancestors were trained to look at the walls and imagine a 3D world that is part of a story. Figure 1.23 shows some examples of this. Cave paintings, such as the one shown in Figure 1.23(a) from 30,000 years ago. Figure 1.23(b) shows a painting from the European Middle Ages. Similar to the cave painting, it relates to military conflict, a fascination of humans regardless of the era or technology. There is much greater detail in the newer painting, leaving less to the imagination; however, the drawing perspective is comically wrong. Some people seem short relative to others, rather than being further away. The rear portion of the fence looks incorrect. Figure 1.23(c) shows a later painting in which the perspective have been meticulously accounted for, leading to a beautiful palace view that requires no imagination for us to perceive it as ``3D''. By the 19th century, many artists had grown tired of such realism and started the controversial impressionist movement, an example of which is shown in Figure 1.23(d). Such paintings leave more to the imagination of the viewer, much like the earlier cave paintings.
Steven M LaValle 2020-01-06