XRSession.md

XRSession

Namespace: SpawnDev.SpawnJS.JSObjects.WebXR
Inheritance: SpawnJSObject -> EventTarget -> XRSession
MDN Reference: XRSession - MDN

The XRSession interface represents an ongoing XR session, providing the context for all XR interactions including rendering, input handling, and spatial tracking.

Constructors

Signature	Description
XRSession(SpawnJSObjectReference _ref)	Deserialization constructor. Obtained via XRSystem.RequestSession().

Properties

Property	Type	Description
RenderState	XRRenderState	The current render state (base layer, depth range).
InputSources	XRInputSource[]	Currently active input sources (controllers, hands).
VisibilityState	string	Visibility: "visible", "visible-blurred", or "hidden".
FrameRate	float?	The current frame rate, if available.
SupportedFrameRates	float[]?	Frame rates that can be requested.

Methods

Method	Return Type	Description
RequestReferenceSpace(string type)	Task<XRReferenceSpace>	Gets a reference space. Types: "local", "local-floor", "bounded-floor", "unbounded", "viewer".
RequestAnimationFrame(Callback callback)	int	Schedules a callback for the next XR frame. Returns a handle.
UpdateRenderState(XRRenderStateInit options)	void	Updates the render state.
End()	Task	Ends the XR session.
RequestHitTestSource(XRHitTestOptionsInit options)	Task<XRHitTestSource>	Creates a hit test source for AR.

Events

Event	Type	Description
OnEnd	ActionEvent<XRSessionEvent>	Fired when the session ends.
OnInputSourcesChange	ActionEvent<XRInputSourcesChangeEvent>	Fired when input sources change.
OnSelect	ActionEvent<XRInputSourceEvent>	Fired on a primary select action (trigger press).
OnSqueeze	ActionEvent<XRInputSourceEvent>	Fired on a squeeze action (grip press).
OnVisibilityChange	ActionEvent<XRSessionEvent>	Fired when visibility state changes.

Example

using var session = await xr.RequestSession("immersive-vr");
using var refSpace = await session.RequestReferenceSpace("local-floor");

// Subscribe using named methods (required for proper cleanup)
session.OnEnd += Session_OnEnd;
session.OnSelect += Session_OnSelect;

// Clean up event handlers before disposal
session.OnEnd -= Session_OnEnd;
session.OnSelect -= Session_OnSelect;

void Session_OnEnd(XRSessionEvent e)
{
    Console.WriteLine("XR session ended");
}

void Session_OnSelect(XRInputSourceEvent e)
{
    Console.WriteLine("User selected something");
}