OrientationSensor

The OrientationSensor interface of the Sensor APIs is the base class for orientation sensors. This interface cannot be used directly. Instead it provides properties and methods accessed by interfaces that inherit from it.

If a feature policy blocks use of a feature it is because your code is inconsistent with the policies set on your server. This is not something that would ever be shown to a user. The Feature-Policy HTTP header article contains implementation instructions.

Below is a list of interfaces based on the OrientationSensor interface.

• AbsoluteOrientationSensor
• RelativeOrientationSensor

OrientationSensor.quaternion

Returns a four element Array whose elements contain the components of the unit quaternion representing the device's orientation.

OrientationSensor.populateMatrix()

Populates the given object with the rotation matrix based on the latest sensor reading. The rotation matrix is shown below.

The following example, which is loosely based on Intel's Orientation Phone demo, instantiates an AbsoluteOrientationSensor with a frequency of 60 times a second. On each reading it uses OrientationSensor.quaternion to rotate a visual model of a phone.

const options = { frequency: 60, referenceFrame: 'device' };
const sensor = new AbsoluteOrientationSensor(options);

sensor.addEventListener('reading', () => {
  // model is a Three.js object instantiated elsewhere.
  model.quaternion.fromArray(sensor.quaternion).inverse();
});
sensor.addEventListener('error', error => {
   if (event.error.name == 'NotReadableError') {
    console.log("Sensor is not available.");
  }
});
sensor.start();

Using orientation sensors requires requesting permissions for multiple device sensors. Because the Permissions interface uses promises, a good way to request permissions is to use Promise.all.

const sensor = new AbsoluteOrientationSensor();
Promise.all([navigator.permissions.query({ name: "accelerometer" }),
             navigator.permissions.query({ name: "magnetometer" }),
             navigator.permissions.query({ name: "gyroscope" })])
       .then(results => {
         if (results.every(result => result.state === "granted")) {
           sensor.start();
           ...
         } else {
           console.log("No permissions to use AbsoluteOrientationSensor.");
         }
   });