VRPose.linearVelocity

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

Browser compatibility

See also

• WebVR API homepage
• MozVr.com — demos, downloads, and other resources from the Mozilla VR team.