VRDisplayCapabilities.canPresent - Web APIs 编辑

Experimental

This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

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

Browser compatibility

BCD tables only load in the browser

See also

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