Sentireal® Blog



July 2014

Virtual Reality - What's in a Name?


As a follow-up to my previous blog post that demystified the term “augmented reality” it seems only reasonable to do the same for Sentireal’s related technology focus – namely “virtual reality”. Virtual reality is currently a hot topic in the technology world, not least because of new high-profile virtual reality devices such as Oculus Rift and Sony Morpheus. This post attempts to demystify what is meant by virtual reality and provide Sentireal’s particular definition, which aligns with that put forward by Sherman and Craig in their book “Understanding Virtual Reality”. In this book, virtual reality is defined as:

“Virtual Reality: A medium composed of interactive computer simulations that sense the participant’s position and replace or augment the feedback to one or more senses – giving the feeling of being immersed or being present in the simulation.”

As we did with the definition of augmented reality, let’s break this definition statement down into its constituent parts and see if we can work out its overall meaning.

A medium …
The preceding blog post outlined why augmented reality should be considered as a communications medium rather than a technology. Virtual reality is similar in that it relies on lots of constituent technologies but its ultimate purpose is to deliver an experience to the consumer. In that sense virtual reality is a medium or an art form, much in the same way that print, music or cinema are. Like any communications medium, if the artistic content delivered by augmented reality is not compelling for the consumer then the sophisticated technology generally won’t rescue the experience. Remember our previous analogy with CGI effects in movies – they can make a good movie great but they can’t rescue a movie with a dire plot and poor acting.

… composed of interactive computer simulations …
The computer simulations are composed of the same type of digital information and content discussed for augmented reality, such as text, graphics, video, audio and, with appropriate devices, even esoteric information such as touch, taste and smell. As with augmented reality, virtual reality has a requirement that the consumer be able to interact with the digital information and objects within the computer simulations. In other words the digital information should be updated in accordance with actions carried out by the consumer on it, such as physically manipulating computer-generated objects with the hands or controlling computer-generated objects with voice or gesture commands. An important aspect of virtual reality is that the consumer is not limited to passively watching the computer simulation unfold in a prescribed fashion in front of them.

… that sense the participant’s position …
Virtual reality systems track the physical position and orientation of the participant (consumer). Therefore changes in participant position or orientation cause appropriate and accurate updates to the position and orientation of scenes and objects depicted in the computer simulation. For example, if the participant takes a step forward in the physical world then the scenes and objects in the computer-generated virtual world need to be redisplayed as if they have moved a corresponding distance in an appropriate direction. If the participant turns their head then the scenes and objects in the virtual world need to be redisplayed as if they have rotated a corresponding distance and in an appropriate direction.

… and replace or augment the feedback to one or more senses – giving the feeling of being immersed or being present in the simulation
Now we come to the essence of what distinguishes virtual reality from augmented reality. Generally, virtual reality creates a completely synthetic (computer-generated) environment. The only thing impinging on the senses of the consumer is digital content, with the physical world essentially abstracted or completely removed. Compare this with augmented reality where digital information is “overlaid onto the physical world”. With augmented reality the consumer perceives the digital information and the physical world together. With virtual reality the digital information is perceived in isolation. Note also that virtual reality systems attempt to induce immersion – whereby the consumer is fooled into believing that the computer-generated virtual world is, in some meaningful way, real. This is why virtual reality is a very effective medium for training and educating people in disciplines and scenarios that are difficult or expensive to physically create.

You made it all the way through – congratulations! Hopefully we have a clear and common understanding of Sentireal’s preferred definition of the term “virtual reality” and how it relates to “augmented reality”. Having covered the technical formalities, future blog posts will start to look at how we can apply these media to education and medical applications and products.