Input devices transfer user actions into values that the software can use.
Commonly these are:
- Head position and rotation
- Hand positions and rotations
- Triggers (single or for multiple fingers)
Depending on the hardware, body and facial tracking information may also be available.
When designing a virtual experience, the available inputs should be considered at all times in order that the design is appropriate for the target platform.
User input should be kept simple and intuitive (e.g. if a controller has a trigger and a button, it makes more sense to pick things up with the trigger, as this is the closest controller action to the action of grasping).
The main output device in a VR system is the visual display. This forms both the user's visual understanding of the world, and their motion within it.
Audio and haptics...
Some systems allow for resistive feedback. These are generally expensive bespoke pieces of kit which are optimised for a specific type of interaction.
Getting from Input to Output
The most simple route from input to output if from the head tracker to the display. If the user moves their head, the display should show a view of the world that moves in the same way.
Similarly, if the user moves their hands (and the tracked controllers they are holding), the virtual representation of their hands should move in the same way.
If the hand controllers have an input that corresponds to opening and closing their hands, the virtual hands should respond accordingly.