snap-turn

Component for reading the input of a thumbstick and using that to effectively rotate the reference in place in discrete steps. This is accomplished by rotating and moving the target. It's assumed that the reference is a descendant of the target. This can be used on the camera rig to achieve snap turning.

Properties

Property	Description	Default Value
enabled	Whether the snap turn is active or not	true
target	Selector for the target to apply rotation and translation to	none
reference	Selector for the reference to 'effectively' rotate	none
turnSize	The rotation per snap (degrees)	45
activateThreshold	The amount the thumbstick needs to be pushed to activate a snap turn	0.9
deactivateThreshold	The threshold the thumbstick needs to cross before a new activation may take place	0.8
delay	Optional delay applied before and after the actual snap rotation takes place	0

Events

Event Name	Emitter	Description
rotation	target	Target was rotated through this component. No movement is also signalled through the motion event
prerotation	target	Target is about to rotate (only when a delay is configured)
postrotation	target	Target has just rotated (only when a delay is configured)

Usage

The snap-turn component needs to be applied to an entity that will emit the axismove event, commenly one of the hands. Below is an example using a camera rig:

<a-entity id="rig">
    <a-entity id="camera" camera position="0 1.6 0" wasd-controls look-controls></a-entity>

    <a-entity vive-controls="hand: right"
              oculus-touch-controls="hand: right"
              snap-turn="target: #rig; reference: #camera">
    </a-entity>
</a-entity>

In case a transition needs to be shown a delay can be configured. This delay is applied twice: before and after the actual snap rotation. This can be used to make a quick fade transition for each snap turn, see al-snap-turn-fade