When talking about VR nowadays, we often think about headsets and controllers. But VR is far more diverse than you would think at first glance. In this post, I will present the CAVE system, an alternative to headsets that is still used today in many research labs.
What is a CAVE?
CAVE stands for Cave Automatic Virtual Environment. It is a room where the walls are screens and where you can walk around freely. It is usually achieved by using projectors and tracking systems. The first CAVE was built in 1992 at the University of Illinois at Chicago Electronic Visualization Laboratory.
You can find the original paper at https://dl.acm.org/doi/abs/10.1145/129888.129892
Why would I use a CAVE and not a headset?
VR might be synonymous with headsets, but it doesn’t mean they don’t have limitations. If you used a VR headset for an extended period of time, you probably know that it can be quite uncomfortable. The headset is heavy and you can’t see your own body. Moreover, other people can’t see what you are doing in VR. This is where the CAVE comes in. It is a more social experience, you can see your own body and other people can see what you are doing. It is also more comfortable as you don’t have to wear a headset, but only a pair of 3D glasses.
The Reality-Virtuality Continuum
It is important to understand that VR and reality are not 2 completely separate things. In fact, there is a continuum between reality and virtuality. On one end of the continuum, you have the real world, on the other end, you have a fully virtual world. In between, you have augmented reality, mixed reality, augmented virtuality and augmented virtuality.
This continuum is called the Reality-Virtuality Continuum and was first introduced by Paul Milgram and Fumio Kishino in 1994.
Where does the CAVE fit in this continuum? It is somewhere between augmented virtuality and augmented reality. It is a virtual environment, but it is not fully virtual as it is still anchored in the real world. You can see your own body and other people can see what you are doing. It is also not augmented reality as the virtual environment is not anchored in the real world, but the real world is anchored in the virtual environment.
What about multiple users?
An interesting side effect of this definition is when using the CAVE system with multiple user. The user can already see its own body in the virtual environment, but the addition of new users will make this position of the spectrum shift a little more towards reality as every user will be able to see everyone, just like in real life.