API Reference

Class List

XrLightEstimation

Extends: EventHandler

Light Estimation provides illumination data from the real world, which is estimated by the underlying AR system. It provides a reflection Cube Map, that represents the reflection estimation from the viewer position. A more simplified approximation of light is provided by L2 Spherical Harmonics data. And the most simple level of light estimation is the most prominent directional light, its rotation, intensity and color.

Summary

Properties

available

True if estimated light information is available.

color

Color of what is estimated to be the most prominent directional light.

intensity

Intensity of what is estimated to be the most prominent directional light.

rotation

Rotation of what is estimated to be the most prominent directional light.

supported

True if Light Estimation is supported.

Methods

end

End estimation of illumination data.

start

Start estimation of illumination data.

Events

available

Fired when light estimation data becomes available.

error

Fired when light estimation has failed to start.

Inherited

Methods

fire

Fire an event, all additional arguments are passed on to the event listener.

hasEvent

Test if there are any handlers bound to an event name.

off

Detach an event handler from an event.

on

Attach an event handler to an event.

once

Attach an event handler to an event.

Details

Properties

booleanavailable

True if estimated light information is available.

if (app.xr.lightEstimation.available) {
    entity.light.intensity = app.xr.lightEstimation.intensity;
}
Color, nullcolor

Color of what is estimated to be the most prominent directional light. Or null if data is not available.

number, nullintensity

Intensity of what is estimated to be the most prominent directional light. Or null if data is not available.

Quat, nullrotation

Rotation of what is estimated to be the most prominent directional light. Or null if data is not available.

booleansupported

True if Light Estimation is supported. This information is available only during an active AR session.

Methods

end()

End estimation of illumination data.

start()

Start estimation of illumination data. Availability of such data will come later and an available event will be fired. If it failed to start estimation, an error event will be fired.

app.xr.on('start', function () {
    if (app.xr.lightEstimation.supported) {
        app.xr.lightEstimation.start();
    }
});

Events

available

Fired when light estimation data becomes available.

error

Fired when light estimation has failed to start.

app.xr.lightEstimation.on('error', function (ex) {
    // has failed to start
});

Parameters

errorError

Error object related to failure of light estimation start.

Inherited

Methods

fire(name, [arg1], [arg2], [arg3], [arg4], [arg5], [arg6], [arg7], [arg8])

Fire an event, all additional arguments are passed on to the event listener.

obj.fire('test', 'This is the message');

Parameters

namestring

Name of event to fire.

arg1*

First argument that is passed to the event handler.

arg2*

Second argument that is passed to the event handler.

arg3*

Third argument that is passed to the event handler.

arg4*

Fourth argument that is passed to the event handler.

arg5*

Fifth argument that is passed to the event handler.

arg6*

Sixth argument that is passed to the event handler.

arg7*

Seventh argument that is passed to the event handler.

arg8*

Eighth argument that is passed to the event handler.

Returns

EventHandler

Self for chaining.

hasEvent(name)

Test if there are any handlers bound to an event name.

obj.on('test', function () { }); // bind an event to 'test'
obj.hasEvent('test'); // returns true
obj.hasEvent('hello'); // returns false

Parameters

namestring

The name of the event to test.

Returns

boolean

True if the object has handlers bound to the specified event name.

off([name], [callback], [scope])

Detach an event handler from an event. If callback is not provided then all callbacks are unbound from the event, if scope is not provided then all events with the callback will be unbound.

const handler = function () {
};
obj.on('test', handler);

obj.off(); // Removes all events
obj.off('test'); // Removes all events called 'test'
obj.off('test', handler); // Removes all handler functions, called 'test'
obj.off('test', handler, this); // Removes all handler functions, called 'test' with scope this

Parameters

namestring

Name of the event to unbind.

callbackHandleEventCallback

Function to be unbound.

scopeobject

Scope that was used as the this when the event is fired.

Returns

EventHandler

Self for chaining.

on(name, callback, [scope])

Attach an event handler to an event.

obj.on('test', function (a, b) {
    console.log(a + b);
});
obj.fire('test', 1, 2); // prints 3 to the console
const evt = obj.on('test', function (a, b) {
    console.log(a + b);
});
// some time later
evt.off();

Parameters

namestring

Name of the event to bind the callback to.

callbackHandleEventCallback

Function that is called when event is fired. Note the callback is limited to 8 arguments.

scopeobject

Object to use as 'this' when the event is fired, defaults to current this.

Returns

EventHandle

Can be used for removing event in the future.

once(name, callback, [scope])

Attach an event handler to an event. This handler will be removed after being fired once.

obj.once('test', function (a, b) {
    console.log(a + b);
});
obj.fire('test', 1, 2); // prints 3 to the console
obj.fire('test', 1, 2); // not going to get handled

Parameters

namestring

Name of the event to bind the callback to.

callbackHandleEventCallback

Function that is called when event is fired. Note the callback is limited to 8 arguments.

scopeobject

Object to use as 'this' when the event is fired, defaults to current this.

Returns

EventHandle
  • can be used for removing event in the future.