PositionSensorVRDevice: getState() method
Deprecated
Avoid using this feature in new projects. Development of the WebVR API halted in favor of WebXR. This feature may be a candidate for removal from web standards or browsers.
Consider using the following features instead: WebXR.
Non-standard: This feature is not standardized. We do not recommend using non-standard features in production, as they have limited browser support, and may change or be removed. However, they can be a suitable alternative in specific cases where no standard option exists.
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 VRPose object. This is the method you'd normally want to use, vs. PositionSensorVRDevice.getImmediateState.
Syntax
getState()
Parameters
None.
Return value
A VRPose object.
Examples
The following example uses the WebVR API to update the view of a simple CanvasRenderingContext2D scene on each frame of a requestAnimationFrame loop.
function setView() {
const posState = gPositionSensor.getState();
if (posState.hasPosition) {
posPara.textContent = `Position: x${roundToTwo(
posState.position.x,
)} y${roundToTwo(posState.position.y)} z${roundToTwo(posState.position.z)}`;
xPos = -posState.position.x * WIDTH * 2;
yPos = posState.position.y * HEIGHT * 2;
zPos = -posState.position.z > 0.01 ? -posState.position.z : 0.01;
}
if (posState.hasOrientation) {
orientPara.textContent = `Orientation: x${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 getState() and storing it in posState. We then check to make sure that position and orientation info is present in the current frame using VRPose.position and VRPose.orientation (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.