MDN wants to learn about developers like you: https://qsurvey.mozilla.com/s3/d6d7ff2e2f9c

VRPose.linearVelocity

This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for usage in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future versions of browsers as the specification changes.

The linearVelocity read-only property of the VRPose interface returns an array representing the linear velocity vector of the VRDisplay at the current VRPose.timestamp, in meters per second.

In other words, the current velocity at which the sensor is moving along the x, y, and z axes.

Syntax

var myLinearVelocity = VRPose.linearVelocity;

Value

A Float32Array, or null if the VR sensor is not able to provide linear velocity data.

Examples

// rendering loop for a VR scene
function drawVRScene() {
  // WebVR: Request the next frame of the animation
  vrSceneFrame = vrDisplay.requestAnimationFrame(drawVRScene);

  // Populate frameData with the data of the next frame to display
  vrDisplay.getFrameData(frameData);

  // Retrieve the linear velocity values for use in rendering
  // curFramePose is a VRPose object
  var curFramePose = frameData.pose;
  var linVel = curFramePose.linearVelocity;
  var lvx = linVel[0];
  var lvy = linVel[1];
  var lvz = linVel[2];

  // render the scene
  ...

  // WebVR: submit the rendered frame to the VR display
  vrDisplay.submitFrame();
}

Specifications

Specification Status Comment
WebVR 1.1
The definition of 'linearVelocity' in that specification.
Editor's Draft Initial definition

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic Support (Yes)1 2 (Yes)553 No ? ?
FeatureAndroidChrome for AndroidEdge mobileFirefox for AndroidIE mobileOpera AndroidiOS Safari
Basic Support No (Yes)4 ? ? No ? ?

1. Only works on desktop in an experimental version of Chrome (other builds won't return any devices when Navigator.getVRDisplays() is invoked).

2. , this feature is behind the WebVR preference. To change preferences in Chrome, visit chrome://flags.

3. Currently only Windows support is enabled by default. Mac support is available in Firefox Nightly.

4. Currently supported only by Google Daydream.

See also

Document Tags and Contributors

 Contributors to this page: fscholz, chrisdavidmills, abbycar, Sebastianz
 Last updated by: fscholz,