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 canPresent read-only property of the VRDisplayCapabilities interface returns a Boolean stating whether the VR display is capable of presenting content (e.g. through an HMD).
This is useful for identifying "magic window" devices that are capable of 6DoF tracking but for which VRDisplay.requestPresent() is not meaningful. If canPresent is false, calls to VRDisplay.requestPresent() will fail, and VRDisplay.getEyeParameters() will return null.
Syntax
var canIPresent = vrDisplayCapabilitiesInstance.canPresent;
Value
A Boolean.
Examples
function reportDisplays() {
navigator.getVRDisplays().then(function(displays) {
for(var i = 0; i < displays.length; i++) {
var cap = displays[i].capabilities;
// cap is a VRDisplayCapabilities object
var listItem = document.createElement('li');
listItem.innerHTML = '<strong>Display ' + (i+1) + '</strong>'
+ '<br>VR Display ID: ' + displays[i].displayId
+ '<br>VR Display Name: ' + displays[i].displayName
+ '<br>Display can present content: ' + cap.canPresent
+ '<br>Display is separate from the computer\'s main display: ' + cap.hasExternalDisplay
+ '<br>Display can return position info: ' + cap.hasPosition
+ '<br>Display can return orientation info: ' + cap.hasOrientation
+ '<br>Display max layers: ' + cap.maxLayers;
list.appendChild(listItem);
}
});
}
Specifications
| Specification | Status | Comment |
|---|---|---|
| WebVR 1.1 The definition of 'canPresent' in that specification. |
Editor's Draft | Initial definition |
Browser compatibility
| Feature | Android | Chrome for Android | Edge mobile | Firefox for Android | IE mobile | Opera Android | iOS 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
- WebVR API homepage
- MozVr.com — demos, downloads, and other resources from the Mozilla VR team.