Locomotion in Qt Quick 3D Xr

In fully immersive VR, the user can move around in the virtual world by walking or even running with enough space, but in most cases, the user is limited to a small area and needs to move around in the virtual world using some form of locomotion that allows for movement over greater distances, or even terrains that aren't possible to replicate in a realistic way in the real world. In VR, locomotion is the act of moving from one place to another, either by having a appropriately sized area (Room Scale) or using some form of input and/or gesture other than physically moving.

In VR, locomotion is achieved using different techniques. Other than room scale, the most common techniques are teleportation or continuous movement. Teleportation is instantly moving the user from one place to another. Continuous movement is moving the user continuously from one place to another, usually using a controller or a keyboard. In both cases, it is essential to design the movement to minimize motion sickness and user disorientation. Getting this right can be a challenge and requires careful design and testing.

Room scale

The best way to experience VR is to have a room-scale setup where the user can walk around in a large enough space. In this setup, the user can move around in the virtual world as they would in the real world, but usually within a predefined space with a sufficient margin to avoid walking into walls or other physical obstacles. This is the most immersive way to experience VR if the user's physical environment allows it.

Teleportation

Teleportation can be done in different ways but is usually done by pointing at a location and then teleporting the user to that location. To avoid causing motion sickness, some form of effect is usually added to indicate that the player was indeed moved without disconnecting the user's view from the real-world head motion inputs from the HMD. This can be done by fading The screen turns black and then fades back to the VR view once the teleportation is done. Teleportation is a good way to move around in larger virtual spaces. In Qt Quick 3D Xr, you can find a reference implementation for doing freeform teleportation, see the Freeform teleportation example for more information.

Continuous movement

Continuous movement is usually better suited for when the explorable area is small or when the user needs more fine-grained control over the movement using a controller or a keyboard. See the XrController documentation for more information on how to get the data from the controller. As with teleportation, it is important to minimize motion sickness and disorientation when using continuous movement. This can be done by, for example, adding a tunneling effect or other effects that soften the movement to avoid motion sickness. This is especially important when starting and stopping movement.