How ``real'' should the VR experience be? It is tempting to try to make it match our physical world as closely as possible. This is referred to in Section 10.1 as the universal simulation principle: Any interaction mechanism in the real world can be simulated in VR. Our brains are most familiar with these settings, thereby making it seem most appropriate. This philosophy has dominated the video game industry at times, for example, in the development of highly realistic first-person shooter (FPS) games that are beautifully rendered on increasingly advanced graphics cards. In spite of this, understand that extremely simple, cartoon-like environments can also be effective and even preferable. Examples appear throughout history, as discussed in Section 1.3.
If you are a creator of VR experiences, think carefully about the task, goals, or desired effect you want to have on the user. You have the opportunity to make the experience better than reality. What will they be doing? Taking a math course? Experiencing a live theatrical performance? Writing software? Designing a house? Maintaining a long-distance relationship? Playing a game? Having a meditation and relaxation session? Traveling to another place on Earth, or in the universe? For each of these, think about how the realism requirements might vary. For example, consider writing software in VR. We currently write software by typing into windows that appear on a large screen. Note that even though this is a familiar experience for many people, it was not even possible in the physical world of the 1950s. In VR, we could simulate the modern software development environment by convincing the programmer that she is sitting in front of a screen; however, this misses the point that we can create almost anything in VR. Perhaps a completely new interface will emerge that does not appear to be a screen sitting on a desk in an office. For example, the windows could be floating above a secluded beach or forest. Furthermore, imagine how a debugger could show the program execution trace. In all of these examples, it will important to determine the perception-based criteria that need to be satisfied for the perceptual illusions to be convincingly and comfortably maintained for the particular VR experience of interest.
Steven M LaValle 2019-03-14