XRReferenceSpaceEvent: transform property

Limited availability

This feature is not Baseline because it does not work in some of the most widely-used browsers.

Secure context: This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.

The read-only XRReferenceSpaceEvent property transform indicates the position and orientation of the affected referenceSpace's native origin after the changes the event represents are applied. The transform is defined using the old coordinate system, which allows it to be used to convert coordinates from the pre-event coordinate system to the post-event coordinate system.

Value

An XRRigidTransform object providing a transform that can be used to convert coordinates from the pre-event coordinate system to the post-event coordinate system.

Usage notes

Upon receiving a reset event, you can apply the transform to cached position or orientation information to shift them into the updated coordinate system. Alternatively, you can just discard any cached positional information and recompute from scratch. The approach you take will depend on your needs.

For details on what causes a reset event and how to respond, see the reset event's documentation.

Examples

This example handles the reset event by walking through all the objects in a scene, updating each object's position by multiplying it with the event's given transform. The scene is represented by a scene object, with all the objects in an array called objects within it.

js
xrReferenceSpace.addEventListener("reset", (event) => {
  for (const obj of scene.objects) {
    mat4.multiply(obj.transform, obj.transform, event.transform);
  }
});

Specifications

Specification
WebXR Device API
# dom-xrreferencespaceevent-transform

Browser compatibility

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