Design Point - VR Locomotion

As our game takes place within a house we needed to develop a locomotion (movement) system that allowed the player to move around the house freely, in order to complete the various tasks within the game.
One of our main challenges was developing a movement system that achieved two main objectives:

• The player must be able to move intuitively through the environment
• The movement must not make the player feel motion sick, which is a common problem that can occur with VR Motion. 

Teleporting

Our initial idea was to implement a teleportation based movement system that moved the player from one point to another, this locomotion method has been used in many VR games such as Budget Cuts, The Lab and most recently Half Life: Alyx. 

VR Teleportation  - from Budget Cuts

This system bypasses most peoples feeling of motion sickness because they are not moving through the world. However, we felt that this system would not work well with our game because the player might not be able to see where they are teleporting to. This would have unintended side effects with the rest of the gameplay, either we would have to show the player where they are teleporting to which would reduce the impact of the sound-based effects, or the player would have no idea what they are teleporting next to, which result in the player becoming confused and disorientated.

Joystick/DPad

Another method of locomotion that we could have used was using the Joystick/DPad of the Vive controller however this caused multiple issues.

Firstly the DPad was already being used as an interaction method within the game, for example, turning off the alarm clock. This would require us to re-map controls, such as using the grip buttons on the side of the controller, to controls that felt less natural to use for those interactions.

Secondly, this method has been widely known as one of the worst locomotion methods for motion stickiness, something which would be exacerbated by the fact that the players' environment was not always visible. To support this a 2019 study into VR Locomiation in the New Era of Virtual Reality concluded that "motion-sickness is still a problematic interaction aspect of controller-based VR locomotion and effective technical solutions are needed, just like the dynamic field-of-view adjustment".

We decided early in development that this would not be an appropriate movement method for our game.

Motion-based 

The solution that we decided on using for our game was a motion-based solution. This involved the player having to swing their arms while pressing the grip buttons on the side of the Vive controller in order to move. The amount that the player moves is directly based on the movement on the player, which reduces the amount of motion sickness that the player will feel. This is supported by Oculus who say "Allowing user control over the motion they experience can minimize discomfort ... Allow users to move themselves through the world instead of taking them for a ride".