Most VR experiences these days are what is referred to as a “sit down” or “stand up” experience. Just as the names suggest, the physical body of the play remains in one spot, either seated on a chair or standing in one place.
If the player’s character needs to move around this is usually achieved by using a number of workarounds. One way to do it is to have the character teleport from one spot to the next. We’ve seen this in games such as Arkham Asylum VR where, as Batman, you can only stand still at any given moment. It’s also a method we saw in DOOM VFR, but in that case the game’s story accounted for it.
The other option is to simply use a gamepad where movement through the world is controlled by way of the pad’s analog joysticks. This works as well as it does for any other 3D game – which is to say, pretty darn well. The problem is that this does not feel very immersive and also makes using motion controls awkward or impossible.
The third alternative is to use your actual feet to move around the way you do in real life. Room-scale VR such as that of the HTC Vive. That’s OK if you’ve designed your VR experience to happen within the confines of a 15×15 foot room, but it’s not going to provide the sort of expansive movement we’ve come to expect in games like Skyrim and the Witcher 3, which are traditional console and PC games.
That’s where the concept of an omnidirectional treadmill comes into play.
Any Direction You Want
We’ve all seen a treadmill. It’s a device that lets you walk or run in one spot, making it easy to get some exercise or train without having to leave the safety of your home or the gym. These treadmills are unidirectional. Well, I guess if they can be put into reverse they’d be bi-directional, but the point is that they are linear.
An omnidirectional treadmill is a device that lets you walk on its surface in any direction. There are different ways in which this can be achieved, but the end result is more or less the same. You can stand in one spot but freely move in any direction. While this is not particularly useful for exercise purposes, simulators can use the motion of the treadmill to translate your walking or running into digital motion.
Strapped In Treadmill
This comes with some inherent issues, however. Whether it’s for a simulation or not, when you walk or run you are expending a significant amount of energy. If you trip, lose your balance, or otherwise mess things up, there’s a serious chance of injury. So omnidirectional treadmill setups tend to be equipped with harnesses and other sorts of safety gear meant to keep you upright and in one piece.
This is one of the reasons they haven’t become all that popular. You need some real motivation just to go to the trouble of strapping on an HMD, much less a body harness.
I have seen some more consumer-oriented omnidirectional treadmills that don’t need all the faff, but they also don’t allow you to run, crouch, or jump. Instead you can only do a sort of walking-pace shuffle. Still, for something that takes up very little space, it’s more immersive than sitting in a chair waggling a joystick to walk.
The Price is Wrong
While I personally think that omnidirectional treadmills are a great idea, I don’t really see them taking over in a big way. They tend to be bulky, heavy, and a pain to operate. One of the pioneers of omnidirectional VR treadmills, Virtuix, has already bailed on the idea of selling directly to consumers; they plan to sell them to VR arcades instead.
There are also more compact alternatives, although they might not feel quite as realistic. One cool idea is to put small sensors on your shoes, and then you can sort of walk in place with the system translating it to full running or walking. Sure, you might look goofy, but then none of the technologies in VR make you look cool. They just make you feel cool and that’s all that matters in the end.