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 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 (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.