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PositionSensorVRDevice.getState

Obsolete
This feature is obsolete.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
Check the Browser compatibility table carefully before using this in production.

The getState() method of the PositionSensorVRDevice interface returns the current state of the position sensor for the current frame (e.g. within the current window.requestAnimationFrame callback) or for the previous frame, contained with a VRPositionState object. This is the method you'd normally want to use, vs. PositionSensorVRDevice.getImmediateState.

Syntax

var myPositionState = PositionSensorVRDevice.getState();

Parameters

None.

Returns

A VRPositionState object.

Examples

The following example is taken from our positionsensorvrdevice demo, which uses the WebVR API to update the view of a simple 2D canvas scene on each frame of a requestAnimationFrame loop.

function setView() {
  var posState = gPositionSensor.getState();
  if(posState.hasPosition) {
    posPara.textContent = 'Position: x' + roundToTwo(posState.position.x) + " y"
                                + roundToTwo(posState.position.y) + " z"
                                + roundToTwo(posState.position.z);
    xPos = -posState.position.x * WIDTH * 2;
    yPos = posState.position.y * HEIGHT * 2;
    if(-posState.position.z > 0.01) {
      zPos = -posState.position.z;
    } else {
      zPos = 0.01;
    }
  }

  if(posState.hasOrientation) {
    orientPara.textContent = 'Orientation: x' + roundToTwo(posState.orientation.x) + " y"
                                + roundToTwo(posState.orientation.y) + " z"
                                + roundToTwo(posState.orientation.z);
    xOrient = posState.orientation.x * WIDTH;
    yOrient = -posState.orientation.y * HEIGHT * 2;
    zOrient = posState.orientation.z * 180;

  }
}

Here we are grabbing a VRPositionState object using getState() and storing it in posState. We then check to make sure that position and orientation info is present in the current frame using VRPositionState.hasPosition and VRPositionState.hasOrientation (these return null if, for example the head mounted display is turned off or not pointing at the position sensor, which would cause an error.)

We then output the x, y and z position and orientation values for informational purposes, and use those values to update the xPos, yPos, zPos, xOrient, yOrient, and zOrient variables, which are used to update the scene rendering on each frame.

Specifications

Specification Status Comment
Unknown
The definition of 'PositionSensorVRDevice' in that specification.
Unknown Initial definition

Browser compatibilityUpdate compatibility data on GitHub

Desktop
Chrome Edge Firefox Internet Explorer Opera Safari
Basic support Yes
Yes
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.
No 39
Disabled
39
Disabled
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
Disabled From version 39: this feature is behind the dom.vr* preference. To change preferences in Firefox, visit about:config.
No No No
Mobile
Android webview Chrome for Android Edge Mobile Firefox for Android Opera for Android iOS Safari Samsung Internet
Basic support No No No 39
Disabled
39
Disabled
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.
Disabled From version 39: this feature is behind the dom.vr* preference. To change preferences in Firefox, visit about:config.
44
The dom.vr* prefs are enabled by default at this point, in Nightly/Aurora editions.
No No No

See also

© 2005–2018 Mozilla Developer Network and individual contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/PositionSensorVRDevice/getState