Class WebARSessionRoot

The WebARSessionRoot is the root object for a WebAR session and used to place the scene in AR.
It is also responsible for scaling the user in AR and optionally creating a XR anchor for the scene placement.

Example

WebARSessionRoot.onPlaced((args) => {
   console.log("Scene has been placed in AR");
});

Hierarchy (view full)

Properties

arTouchTransform autoCenter autoPlace customReticle? gameObject guid invertForward sourceId? useXRAnchor

Accessors

activeAndEnabled arScale context destroyed enabled forward hideFlags layer name right scene static tag up worldEuler worldPosition worldQuaternion worldRotation

Methods

addEventListener awake destroy dispatchEvent earlyUpdate? lateUpdate? onAfterRender? onBeforeRender? onBeforeXR? onCollisionEnter? onCollisionExit? onCollisionStay? onDestroy onDisable onEnable onEnterXR onLeaveXR onPausedChanged? onPointerClick? onPointerDown? onPointerEnter? onPointerExit? onPointerMove? onPointerUp? onTriggerEnter? onTriggerExit? onTriggerStay? onUpdateXR onValidate? onXRControllerAdded? onXRControllerRemoved? removeEventListener resolveGuids? setWorldPosition setWorldQuaternion setWorldRotation start? startCoroutine stopCoroutine supportsXR update? onPlaced

Properties

arTouchTransform

arTouchTransform: boolean = true

Enable touch transform to translate, rotate and scale the scene in AR with multitouch

Default

true

autoCenter

autoCenter: boolean = false

When enabled the scene center will be automatically calculated from the content in the scene

autoPlace

autoPlace: boolean = false

When enabled the scene will be placed automatically when a point in the real world is found

Default

false

OptionalcustomReticle

customReticle?: AssetReference

When assigned this asset will be loaded and visualize the placement while in AR

Default

null

gameObject

gameObject: GameObject

the object this component is attached to. Note that this is a threejs Object3D with some additional features

guid

guid: string = "invalid"

the unique identifier for this component

invertForward

invertForward: boolean = false

When enabled the placed scene forward direction will towards the XRRig

Deprecated

Default

false

OptionalsourceId

sourceId?: string

holds the source identifier this object was created with/from (e.g. if it was part of a glTF file the sourceId holds the url to the glTF)

useXRAnchor

useXRAnchor: boolean = false

Experimental: When enabled we will create a XR anchor for the scene placement
and make sure the scene is at that anchored point during a XR session

Default

false

Accessors

activeAndEnabled

  • get activeAndEnabled(): boolean

  • Returns boolean

    true if the object is enabled and active in the hierarchy

arScale

  • get arScale(): number

  • The scale of a user in AR:
    Note: a large value makes the scene appear smaller

    Returns number

    Default

    1
  • set arScale(val): void

  • Parameters

    • val: number

    Returns void

context

  • get context(): Context

  • Use the context to get access to many Needle Engine features and use physics, timing, access the camera or scene

    Returns Context

  • set context(context): void

  • Parameters

    Returns void

destroyed

  • get destroyed(): boolean

  • Returns boolean

    true if this component was destroyed (this.destroy()) or the whole object this component was part of

enabled

  • get enabled(): boolean

  • Returns boolean

  • set enabled(val): void

  • Parameters

    • val: boolean

    Returns void

forward

  • get forward(): Vector3

  • Forward (0,0,-1) vector in world space

    Returns Vector3

hideFlags

  • get hideFlags(): HideFlags

  • Returns HideFlags

layer

  • get layer(): number

  • Returns number

    the layer of the gameObject this component is attached to

name

  • get name(): string

  • Returns string

    the name of the gameObject this component is attached to

  • set name(str): void

  • Parameters

    • str: string

    Returns void

right

  • get right(): Vector3

  • Right (1,0,0) vector in world space

    Returns Vector3

scene

  • get scene(): Scene

  • shorthand for this.context.scene

    Returns Scene

    the scene of the context

static

  • get static(): boolean

  • Is the gameObject marked as static

    Returns boolean

  • set static(value): void

  • Parameters

    • value: boolean

    Returns void

tag

  • get tag(): string

  • Returns string

    the tag of the gameObject this component is attached to

  • set tag(str): void

  • Parameters

    • str: string

    Returns void

up

  • get up(): Vector3

  • Up (0,1,0) vector in world space

    Returns Vector3

worldEuler

  • get worldEuler(): Euler

  • Returns Euler

  • set worldEuler(val): void

  • Parameters

    Returns void

worldPosition

  • get worldPosition(): Vector3

  • Returns Vector3

  • set worldPosition(val): void

  • Parameters

    Returns void

worldQuaternion

  • get worldQuaternion(): Quaternion

  • Returns Quaternion

  • set worldQuaternion(val): void

  • Parameters

    Returns void

worldRotation

  • get worldRotation(): Vector3

  • Returns Vector3

  • set worldRotation(val): void

  • Parameters

    Returns void

Methods

addEventListener

  • addEventListener<T>(type, listener): void

  • Appends an event listener for events whose type attribute value is type. The callback argument sets the callback that will be invoked when the event is dispatched.

    The options argument sets listener-specific options. For compatibility this can be a boolean, in which case the method behaves exactly as if the value was specified as options's capture.

    When set to true, options's capture prevents callback from being invoked when the event's eventPhase attribute value is BUBBLING_PHASE. When false (or not present), callback will not be invoked when event's eventPhase attribute value is CAPTURING_PHASE. Either way, callback will be invoked if event's eventPhase attribute value is AT_TARGET.

    When set to true, options's passive indicates that the callback will not cancel the event by invoking preventDefault(). This is used to enable performance optimizations described in § 2.8 Observing event listeners.

    When set to true, options's once indicates that the callback will only be invoked once after which the event listener will be removed.

    If an AbortSignal is passed for options's signal, then the event listener will be removed when signal is aborted.

    The event listener is appended to target's event listener list and is not appended if it has the same type, callback, and capture.

    MDN Reference

    Type Parameters

    Parameters

    • type: string
    • listener: ((evt: T) => any)
        • (evt): any

        • Parameters

          • evt: T

          Returns any

    Returns void

awake

  • awake(): void

  • called once when the component becomes active for the first time (once per component)
    This is the first callback to be called

    Returns void

destroy

  • destroy(): void

  • Destroys this component (and removes it from the object)

    Returns void

dispatchEvent

  • dispatchEvent(evt): boolean

  • Dispatches a synthetic event event to target and returns true if either event's cancelable attribute value is false or its preventDefault() method was not invoked, and false otherwise.

    MDN Reference

    Parameters

    Returns boolean

OptionalearlyUpdate

  • earlyUpdate(): void

  • first callback in a frame (called every frame when implemented)

    Returns void

OptionallateUpdate

  • lateUpdate(): void

  • late callback in a frame (called every frame when implemented)

    Returns void

OptionalonAfterRender

OptionalonBeforeRender

  • onBeforeRender(frame): void

  • called before the scene gets rendered in the main update loop

    Parameters

    • frame: null | XRFrame

    Returns void

OptionalonBeforeXR

  • onBeforeXR(mode, args): void

  • Called before the XR session is requested. Use this callback if you want to modify the session init features

    Parameters

    • mode: XRSessionMode
    • args: XRSessionInit

    Returns void

OptionalonCollisionEnter

OptionalonCollisionExit

OptionalonCollisionStay

onDestroy

  • onDestroy(): void

  • Called when the component gets destroyed

    Returns void

onDisable

  • onDisable(): void

  • called every time the component gets disabled or if a parent object (or this.gameObject) gets set to invisible

    Returns void

onEnable

  • onEnable(): void

  • called every time when the component gets enabled (this is invoked after awake and before start)
    or when it becomes active in the hierarchy (e.g. if a parent object or this.gameObject gets set to visible)

    Returns void

onEnterXR

  • onEnterXR(_args): void

  • Callback when this component joins a xr session (or becomes active in a running XR session)

    Parameters

    Returns void

onLeaveXR

  • onLeaveXR(): void

  • Callback when this component exists a xr session (or when it becomes inactive in a running XR session)

    Returns void

OptionalonPausedChanged

  • onPausedChanged(isPaused, wasPaused): void

  • Called for all scripts when the context gets paused or unpaused

    Parameters

    • isPaused: boolean
    • wasPaused: boolean

    Returns void

OptionalonPointerClick

  • onPointerClick(args): any

  • Called when an object (or any child object) is clicked (needs a EventSystem in the scene)

    Parameters

    Returns any

OptionalonPointerDown

OptionalonPointerEnter

  • onPointerEnter(args): any

  • Called when a pointer (mouse, touch, xr controller) starts pointing on/hovering an object (or a child object)

    Parameters

    Returns any

OptionalonPointerExit

  • onPointerExit(args): any

  • Called when a pointer (mouse, touch, xr controller) exists an object (it was hovering the object before but now it's not anymore)

    Parameters

    Returns any

OptionalonPointerMove

  • onPointerMove(args): any

  • Called when a pointer (mouse, touch, xr controller) is moving over an object (or a child object)

    Parameters

    Returns any

OptionalonPointerUp

  • onPointerUp(args): any

  • Called when a button is released (which was previously pressed in onPointerDown)

    Parameters

    Returns any

OptionalonTriggerEnter

OptionalonTriggerExit

OptionalonTriggerStay

onUpdateXR

OptionalonValidate

  • onValidate(prop?): void

  • called when you decorate fields with the @validate() decorator

    Parameters

    • Optionalprop: string

      the name of the field that was changed

    Returns void

OptionalonXRControllerAdded

  • onXRControllerAdded(args): void

  • Callback when a controller is connected/added while in a XR session
    OR when the component joins a running XR session that has already connected controllers
    OR when the component becomes active during a running XR session that has already connected controllers

    Parameters

    Returns void

OptionalonXRControllerRemoved

removeEventListener

  • removeEventListener<T>(type, listener): void

  • Removes the event listener in target's event listener list with the same type, callback, and options.

    MDN Reference

    Type Parameters

    Parameters

    • type: string
    • listener: ((arg: T) => any)
        • (arg): any

        • Parameters

          • arg: T

          Returns any

    Returns void

OptionalresolveGuids

  • resolveGuids(guidsMap): void

  • called on a component with a map of old to new guids (e.g. when instantiate generated new guids and e.g. timeline track bindings needs to remape them)

    Parameters

    • guidsMap: GuidsMap

    Returns void

setWorldPosition

setWorldQuaternion

  • setWorldQuaternion(x, y, z, w): void

  • Parameters

    • x: number
    • y: number
    • z: number
    • w: number

    Returns void

setWorldRotation

  • setWorldRotation(x, y, z, degrees?): void

  • Parameters

    • x: number
    • y: number
    • z: number
    • degrees: boolean = true

    Returns void

Optionalstart

  • start(): void

  • called at the beginning of a frame (once per component)

    Returns void

startCoroutine

  • startCoroutine(routine, evt?): Generator<unknown, any, unknown>

  • starts a coroutine (javascript generator function)
    yield will wait for the next frame:

    • Use yield WaitForSeconds(1) to wait for 1 second.
    • Use yield WaitForFrames(10) to wait for 10 frames.
    • Use yield new Promise(...) to wait for a promise to resolve.

    Parameters

    • routine: Generator<unknown, any, unknown>

      generator function to start

    • evt: FrameEvent = FrameEvent.Update

      event to register the coroutine for (default: FrameEvent.Update). Note that all coroutine FrameEvent callbacks are invoked after the matching regular component callbacks. For example FrameEvent.Update will be called after regular component update() methods)

    Returns Generator<unknown, any, unknown>

    the generator function (use it to stop the coroutine with stopCoroutine)

    Example

    onEnable() { this.startCoroutine(this.myCoroutine()); }
    private *myCoroutine() {
       while(this.activeAndEnabled) {
          console.log("Hello World", this.context.time.frame);
          // wait for 5 frames
          for(let i = 0; i < 5; i++) yield;
       }
    }

stopCoroutine

  • stopCoroutine(routine, evt?): void

  • Stop a coroutine that was previously started with startCoroutine

    Parameters

    • routine: Generator<unknown, any, unknown>

      the routine to be stopped

    • evt: FrameEvent = FrameEvent.Update

      the frame event to unregister the routine from (default: FrameEvent.Update)

    Returns void

supportsXR

  • supportsXR(mode): boolean

  • Optional callback, you can implement this to only get callbacks for VR or AR sessions if necessary.

    Parameters

    • mode: XRSessionMode

    Returns boolean

    true if the mode is supported (if false the mode is not supported by this component and it will not receive XR callbacks for this mode)

Optionalupdate

  • update(): void

  • regular callback in a frame (called every frame when implemented)

    Returns void

StaticonPlaced

  • onPlaced(cb): (() => void)

  • Event that is called when the scene has been placed in AR.

    Parameters

    Returns (() => void)

    a function to remove the event listener

      • (): void

      • Returns void

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