With numerous technologies out there to cope with VR Locomotion, we could possibly combine some of them together to come up with a better solution. For example, VR shoes which negate forward movements can be combined with a regular treadmill that handles the lateral movements so that sideways motion is supported as well. However, the drawbacks of each technology still remains, such as the lack of detection of inertia for treadmills which causes issues when a running person comes to a sudden stop.
VR locomotion is a tricky topic to tackle as considerations for how the user feels is important. It must be intuitive and at the same time, not cause sickness.
An idea that I can think of is to perhaps create a type of controller that sense the grip strength of the player. Then, combined with the eye tracking to get where the player is looking in the scene, there can be a gestured input that requires the player to exert some grip strength and a pulling motion before the player is quickly moved to their desired position based on the gaze with the peripheral blacked out.
I think that this will be intuitive and interesting as it will feel that you are exerting some sort of power with the grip strength requirement to pull yourself towards to location that is far away. With the blacking out of the player’s peripheral, the player will also be less likely to feel motion sickness.
Locomotion in VR is hard to be implemented correctly due to the fact that a wrong implementation could cause motion sickness. Most locomotion is implemented by having physical movement from the player or limited movement from the player. I feel that a good way to do this might be allowing the player to lie on a bed and he can move the in-game character by using motion tracking devices with his hand. Hence when the in-game character is moving in VR, the player would not feel too sick as he is resting his head on the bed and can be more relaxed as compared to standing upright to play the game. This might help in reducing motion sickness as the player senses are more relaxed and the locomotion in VR would not be too drastic for the player who is lying on the bed. Furthermore, the player can only move a little while lying on the bed and this might help the player to not overthink the complicated movement introduced by the VR game, allowing the player to feel secure and less likely to feel motion sickness.
One of the big problems with motion sickness in VR comes from the player’s movement being different from what the brain expects. There was this multi-directional treadmill device I saw a few years back that moved the user in the opposite direction of where they walked in the XY axis. If I recall correctly it did not allow for vertical movement as the harness is attached to a fixed point around the waist. I think an improvement would be to have the harness attached to the ceiling by 3 or 4 ropes. Then the tension of these ropes can be used to determine the player’s movement in all 3 dimensions (if the player crouches then the ropes will be pulled downwards, etc). All other parts of the setup would remain the same including the treadmill. With this setup the player can probably jump and crouch similar to in real life.
When considering the implementation of VR locomotion, there are two main obstacles to overcome: tracking movement and constraint of physical space.
To properly track movement, I feel that a system using cameras and predictive movements can be employed. We’ve had the Kinect and Wii for decades now, and detection of a player’s movements without the excessive use of wearables should be more than possible with today’s technology. Multiple cameras can be set up across a room to detect a player’s movements within a three-dimensional space. However, there still may be issues with over-detection or a disconnect between the player’s physical movements and that of the avatar. Sometimes a player may just be adjusting themselves slightly, but their movement may prompt the avatar to move forward as well. To reduce such issues, or to prevent ‘unnatural’ feeling movements, predictive analytics can be adapted to predict the player’s movements.
A larger issue with seamless VR locomotion would be the constraint of physical space. While the virtual environment can be as large as the developer wants, the player will be constrained by the size of the physical space they are in. I feel that VR treadmills are a good way to overcome this limitation. Though they may get in the way of how ‘realistic’ movement feels, keeping the player physically in the same spot may be the only way to overcome physical space constraints.
That being said, these are very niche and expensive ways of employing VR locomotion and it may need years of research and development before it can be accessible to the everyday consumer.