RelativeOrientationSensor

The RelativeOrientationSensor interface of the Sensor APIs describes the device's physical orientation without regard to the Earth's reference coordinate system.

To use this sensor, the user must grant permission to the 'accelerometer', and 'gyroscope' device sensors through the Permissions API. In addition, this feature may be blocked by a Permissions Policy set on your server.

Constructor

{{domxref("RelativeOrientationSensor.RelativeOrientationSensor", "RelativeOrientationSensor()")}}
- : Creates a new RelativeOrientationSensor object.

Instance properties

No specific properties; inherits properties from its ancestors {{domxref('OrientationSensor')}} and {{domxref('Sensor')}}.

Instance methods

No specific methods; inherits methods from its ancestors {{domxref('OrientationSensor')}} and {{domxref('Sensor')}}.

Events

No specific events; inherits events from its ancestor, {{domxref('Sensor')}}.

Examples

Basic Example

The following example, which is loosely based on Intel's Orientation Phone demo, instantiates a RelativeOrientationSensor with a frequency of 60 times a second.

[!NOTE] The Intel demo this is based on uses the AbsoluteOrientationSensor. On each reading it uses {{domxref('OrientationSensor.quaternion')}} to rotate a visual model of a phone.

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

Permissions Example

Using orientation sensors requires requesting permissions for multiple device sensors. Because the {{domxref('Permissions')}} interface uses promises, a good way to request permissions is to use {{jsxref('Promise.all')}}.

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