WebXRController: Add grip update event if enabled. (#33118)

Co-authored-by: Michael Herzog <michael.herzog@human-interactive.org>

src/renderers/webxr/WebXRController.js

@@ -109,6 +109,7 @@ class WebXRController {
 			this._grip.linearVelocity = new Vector3();
 			this._grip.hasAngularVelocity = false;
 			this._grip.angularVelocity = new Vector3();
+			this._grip.eventsEnabled = false;
 
 		}
 
@@ -321,6 +322,17 @@ class WebXRController {
 
 						}
 
+						// grip update event if enabled
+						if ( grip.eventsEnabled ) {
+
+							grip.dispatchEvent( {
+								type: 'gripUpdated',
+								data: inputSource,
+								target: this
+							} );
+
+						}
+
 					}
 
 				}