Recent years have brought around massive progress in virtual reality technologies. Most of these improvements have centered around the popular Head Mounted Displays (HMDs). Year on year, they seem to improve in regard to resolution, tracking systems, comfort, ease-of-use and incorporating new technologies such as eye tracking or hand tracking.
These improvements have opened the door for extended use of VR headsets in industrial, commercial and professional settings. Both the intensity of use of VR and the number of fields of applications are growing, which in turn creates new challenges and turns the spotlight onto well-known limitations, which becomes increasingly important the more VR is professionally used.
Perhaps the most pertinent of these challenges is the subject of VR locomotion; moving through large virtual spaces that are larger than the freely available space in the real world.
An obvious approach to address this challenge is to create a system that keeps a user in spot, while allowing him or her to walk through infinitely sized VR environments. Such a system removes any spatial limitations, enabling free VR locomotion of arbitrary size or shape.
It is however less obvious how to create such a system in the best possible way. So, let’s have a look at existing systems addressing this challenge first.
VR Locomotion: What’s already there?
In general, there are two categories of VR locomotion devices: passive ones, that are not motorized, and actively powered systems, that actively support the walking movements of a user with the help of a motorized system.
Passive (not motorized) systems were launched a number of years ago and can be considered to be commercially available today. These systems, that are mostly based on low friction surfaces the user stands upon, require the user to overcome the remaining friction underneath the feet by pushing his or her center of gravity forwards.
Typically, a user needs to constantly push his or her hips forwards, against a harness or ring construction. Alternatively, a user can also be held in place from the back using a modified form of harness, in which the user pushes forwards as well.
Due to the requirement of constantly pushing the hips forwards, these systems by concept require the user to keep a special posture while walking. Aside from requiring getting used to this posture, such systems also increase the physical effort compared to regular walking.
Actively powered systems, that move some form of belts, conveyors or rollers underneath the user’s feet, have been prototyped for an even longer period of time.
By concept, these devices are similar to treadmills used for fitness purposes, with two main differences. Firstly, they should work omnidirectionally, allowing a user to walk in any direction. Secondly, they need to give the control of speed and direction of movement to the user.
This is a major difference compared to treadmills used for fitness purposes, on which the movement speed is pre-set (by pressing buttons or similar activities) and the user needs to adapt his body’s movement speed accordingly. In contrast, a VR Treadmill needs to do the opposite, it needs to swiftly adapt its speed to the movements of the user.
Accelerating and decelerating on a belt underneath his or her body results in horizontal forces applied to the feet, which makes walking on such a system unstable. Everyone can easily try that effect by standing on a carpet that another person abruptly pulls on.
Naturally, the severity of this issue increases with the appearance of fast movements of a user. In order to keep up with fast movements of a user, applied accelerations need to be particularly high, which in turn results in specifically strong forces applied to the user’s feet, maximizing instability of the user.
As you can probably see already, optimally supporting a user in walking in VR is not trivial. So, which way did development lead us?
The new Virtualizer ELITE 2 and its concept
In order to overcome these briefly touched limitations, Cyberith created a product that is both actively powered, in order to support the walking movements of the user, and also avoids any horizontal forces applied to the user’s feet, as such would create the discussed “pulling effect”.
The system works by implementing a motion platform into a VR locomotion device. The low friction surface the user stands upon, is based on a motion platform with 2 degrees of freedom of motion, that is actively controlled by electric motors.
In order to facilitate the user’s feet to glide easily, the platform is elevated in front of the user, leading to a slight inclination of the base. In normal conditions, a slight inclination with an angle between 2° and 8° is sufficient in order to enable an effortless gliding of the feet.
The system reacts to a rotation of the user by moving the baseplate in a way, that the elevation continues to be in front of the user. It does so without rotating the platform, but by lowering and increasing the height at different points. Thus, the platform’s inclination rotates with the user’s rotation, without requiring the platform to rotate itself.
Due to this concept, the Virtualizer ELITE 2 does not apply any horizontal forces to the user’s feet, which causes people to lose their balance. The active support, allowing for an easy gliding of the user’s feet – and thus for an easy walk – is provided indirectly via an inclination of the motion platform.
Compared to passive systems, this new actively powered product does not require the user to keep a special posture, caused by the need of constantly pushing the hips forwards. Thus, it makes walking much easier. It also reduces the physical effort related to the walking movement.
Compared to actively powered belt systems, it has two major advantages:
Firstly, there are no horizontal forces applied to the user’s feet. Vertical forces underneath the user’s feet are causing significantly less instability compared to horizontal forces.
Secondly, the forces applied to the user’s feet are much smaller. The bands of a belt based system need to be moved for many meters when a user starts walking on it. In comparison, to reach the required inclination, a certain point on the Virtualizer ELITE 2’s platform, that is located underneath a foot needs to be moved for a few centimeters only. The shorter the required movement distance, the lower the accelerations required in order to keep up with the user’s movements.
Due to these benefits, the new product allows to walk through infinitely sized virtual environments with ease and comfort. The forces applied to the user’s feet are barely noticeable and fast movement speeds are possible without limitations.
What is it used for?
A Virtualizer can be used for any purposes requiring walking through VR. It is most useful whenever the desired virtual world is larger than the freely available space in the real space and physical or intuitive walking is desired.
As the desire to walk through VR is widespread, Virtualizer ELITE 2 products are typically used for a wide variety of applications, including industrial training, training of security personnel, simulation of processes, commercial entertainment, research and medical purposes.
All of these applications are possible, because Cyberith offers an easy-to-use software interface, that includes native SDKs, plugins for the most common 3D engines, SteamVR compatibility and a list of supported industry-specific applications.
For learning more about how Cyberith’s solution for walking in VR, the Virtualizer ELITE 2, could benefit your specific applications, please reach out to Holger Hager ([email protected]) at any time.