This class represents an abstraction of the WebXR Device API and is internally used by [page:WebGLRenderer]. [name] also provides a public interface that allows users to enable/disable XR and perform XR related tasks like for instance retrieving controllers.
This flag notifies the renderer to be ready for XR rendering. Default is *false*. Set it to *true* if you are going to use XR in your app.
Whether XR presentation is active or not. Default is *false*. This flag is read-only and automatically set by [name].
[page:Integer index] — The index of the controller.
Returns a [page:Group] representing the so called *target ray* space of the controller.
Use this space for visualizing 3D objects that support the user in pointing tasks like UI interaction.
[page:Integer index] — The index of the controller.
Returns a [page:Group] representing the so called *grip* space of the controller.
Use this space if the user is going to hold other 3D objects like a lightsaber.
Note: If you want to show something in the user's hand AND offer a pointing ray at the same time, you'll want to attached the handheld object to the group returned by [page:.getControllerGrip]() and the ray to the group returned by [page:.getController](). The idea is to have two different groups in two different coordinate spaces for the same WebXR controller.
[link:https://github.com/mrdoob/three.js/blob/master/src/[path].js src/[path].js]