Web/API/XRRigidTransform/position

The read-only XRRigidTransform property position is a DOMPointReadOnly object which provides the 3D point, specified in meters, describing the translation component of the transform.

Syntax

let pos = xrRigidTransform.position;

Value

A read-only DOMPointReadOnly indicating the 3D position component of the transform matrix. The units are meters.

Note: The w component of the point is always 1.0.

Example

To create a reference space which can be used to place an object at eye level (assuming eye level is 1.5 meters):

function onSessionStarted(xrSession) {
  xrSession.addEventListener("end", onSessionEnded);

  gl = initGraphics(xrSession);

  let glLayer = new XRWebGLLayer(xrSession, gl);
  xrSession.updateRenderState({ baseLayer: glLayer });

  if (immersiveSession) {
    xrSession.requestReferenceSpace("bounded-floor").then((refSpace) => {
      refSpaceCreated(refSpace);
    }).catch(() => {
      session.requestReferenceSpace("local-floor").then(refSpaceCreated);
    });
  } else {
    session.requestReferenceSpace("viewer").then(refSpaceCreated);
  }
}

function refSpaceCreated(refSpace) {
  if (immersiveSession) {
    xrReferenceSpace = refSpace;
  } else {
    xrReferenceSpace = refSpace.getOffsetReferenceSpace(
      new XRRigidTransform({y: -1.5});
    );
  }
  xrSession.requestAnimationFrame(onFrame);
}

After setting up the graphics context for WebXR use, this begins by looking to see if a variable immersiveSession is true; if so, we first request a bounded-floor reference space. if that fails (probably because bounded-floor isn't supported), we try requesting a local-floor reference space.

If we're not in an immersive session, we instead request a viewer reference space.

In all cases, once the space has been obtained, it gets passed into the refSpaceCreated() function. For immersive spaces, the specified space is simply saved for future use. However, for inline sesions, we know we're in a space not automatically adjusted for floor level, so we request an offset reference space to shift the viewer's height to 1.5 meters above the presumed floor level of 0 meters. That new reference space is used instead of the one initially received.

Finally, an animation frame request is submitted.

Specifications

Specification	Status	Comment
WebXR Device APIThe definition of 'XRRigidTransform.position' in that specification.	Working Draft	Initial definition.

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
position	Chrome Full support 79	Edge Full support 79	Firefox No support No	IE No support No	Opera No support No	Safari No support No	WebView Android No support No	Chrome Android Full support 79	Firefox Android No support No	Opera Android No support No	Safari iOS No support No	Samsung Internet Android Full support 11.2

Legend

Full support  

Full support

No support  

No support

XRRigidTransform.position by Mozilla Contributors is licensed under CC-BY-SA 2.5.