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
| Feature | Chrome | Edge | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
|---|---|---|---|---|---|---|
| Basic support | No support[1] | (Yes) | 55 (55)[2] | No support | No support | No support |
| Feature | Android | Edge | Firefox Mobile (Gecko) | IE Phone | Opera Mobile | Safari Mobile | Chrome for Android | Samsung Internet for GearVR |
|---|---|---|---|---|---|---|---|---|
| Basic support | No support | No support | 55.0 (55) | No support | No support | No support | (Yes)[3] | (Yes) |
[1] API Available on all platforms behind a flag, but currently only works on desktop in an experimental version of Chrome (other builds won't return any devices when Navigator.getVRDisplays() is invoked).
[2] Currently only Windows support is enabled by default. Mac support is available in Firefox Nightly.
[3] Currently supported only by Google Daydream.
See also
- WebVR API homepage
- MozVr.com — demos, downloads, and other resources from the Mozilla VR team.