PositionSensorVRDevice.getImmediateState()

Deprecated

This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.

Experimental

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

The getImmediateState() method of the VRDisplay interface returns the current instantaneous position sensor state. This is intended to only be used rarely, for certain special uses, for example sampling the immediate position of a hand orientation sensor — or at least it will be, in the future.

For most standard uses, you'll probably want to use PositionSensorVRDevice.getState instead.

Syntax

var myPositionstate = PositionSensorVRDevice.getImmediateState();

Parameters

None.

Returns

A VRPose object.

Examples

Our positionsensorvrdevice demo uses the WebVR API to update the view of a simple 2D canvas scene on each frame of a requestAnimationFrame loop. The main function that updates the view data is as follows:

function setView() {
  var posState = gPositionSensor.getImmediateState();
  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 VRPose object using getImmediateState() and storing it in posState (the actual live demo uses getState(), but both seem to do the same thing currently.) We then check to make sure that position and orientation info is present in the current frame using VRPose.hasPosition and VRPose.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.

Browser compatibility

BCD tables only load in the browser

See also