This feature is obsolete. Although it may still work in some browsers, its use is discouraged since it could be removed at any time. Try to avoid using it.

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 VRFieldOfViewReadOnly interface of the WebVR API contains the raw definition for the degree value properties required to define a field of view. Inherited by VRFieldOfView.


VRFieldOfViewReadOnly.upDegrees Read only
The number of degrees upward that the field of view extends.
VRFieldOfViewReadOnly.rightDegrees Read only
The number of degrees to the right that the field of view extends.
VRFieldOfViewReadOnly.downDegrees Read only
The number of degrees downwards that the field of view extends.
VRFieldOfViewReadOnly.leftDegrees Read only
The number of degrees to the left that the field of view extends.


You wouldn't ever use this object directly; for some useful examples see the VRFieldOfView page.

To access the properties directly, you could do something like this:

var lEye = myHMDVRDevice.getEyeParameters('left');

// returns something like 53.09438550469889
// returns something like 47.52769258067174
// returns something like 53.09438550469889
// returns something like 46.63209579904155


Specification Status Comment
The definition of 'VRFieldOfViewReadOnly' in that specification.
Editor's Draft Initial definition

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support (Yes)[1] 39 (39)[2] No support No support No support
Feature Android Firefox Mobile (Gecko) Firefox OS (Gecko) IE Phone Opera Mobile Safari Mobile Chrome for Android
Basic support No support 39.0 (39)[2]
44.0 (44)[3]
No support No support No support No support No support
  • [1] The support in Chrome is currently experimental. To find information on Chrome's WebVR implementation status including supporting builds, check out Bringing VR to Chrome by Brandon Jones.
  • [2] The support for this feature is currently disabled by default in Firefox. To enable WebVR support in Firefox Nightly/Developer Edition, you can go to about:config and enable the dom.vr* prefs. A better option however is to install the WebVR Enabler Add-on, which does this for you and sets up other necessary parts of the environment.
  • [3] The dom.vr* prefs are enabled by default at this point, in Nightly/Aurora editions.

See also


© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.

API Experimental Expérimental Interface Obsolete Reference Référence Virtual Reality VR VRFieldOfViewReadOnly WebVR