This is an experimental technology
Check the Browser compatibility table carefully before using this in production.
The timestamp
read-only property of the VRFrameData
interface returns a constantly increasing timestamp value representing the time a frame update occurred.
Timestamps are useful for determining if position state data has been updated from the hardware. Since values are monotonically increasing, they can be compared to determine the ordering of updates — newer values will always be greater than or equal to older values.
The timestamp starts at 0 the first time VRDisplay.getFrameData()
is invoked for a given VRDisplay
.
Syntax
var myTimestamp = vrFrameDataInstance.timestamp;
Value
A DOMHighResTimeStamp
object.
Examples
var frameData = new VRFrameData();
var vrDisplay;
navigator.getVRDisplays().then(function(displays) {
vrDisplay = displays[0];
console.log('Display found');
// Starting the presentation when the button is clicked: It can only be called in response to a user gesture
btn.addEventListener('click', function() {
vrDisplay.requestPresent([{ source: canvas }]).then(function() {
drawVRScene();
});
});
});
// WebVR: Draw the scene for the WebVR display.
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);
// grab the current timestamp on each run of the rendering loop
// and do something with it
framedata.timestamp
...
// WebVR: Indicates that we are ready to present the rendered frame to the VR display
vrDisplay.submitFrame();
}
Specifications
Specification | Status | Comment |
---|---|---|
WebVR 1.1 The definition of 'timestamp' in that specification. |
Editor's Draft | Initial definition |
Browser compatibility
Feature | Chrome | Edge | Firefox | Internet Explorer | Opera | Safari |
---|---|---|---|---|---|---|
Basic support | Yes1 2 | Yes | 553 584 | No | ? | ? |
Feature | Android webview | Chrome for Android | Edge mobile | Firefox for Android | IE mobile | Opera Android | iOS Safari |
---|---|---|---|---|---|---|---|
Basic support | No | Yes5 | ? | ? | 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. Windows support was enabled in Firefox 55.
4. macOS support was enabled in Firefox 58.
5. Currently supported only by Google Daydream.
See also
- WebVR API homepage
- MozVr.com — demos, downloads, and other resources from the Mozilla VR team.