The transform read-only attribute of the XRPose interface is a XRRigidTransform object providing the position and orientation of the pose relative to the base XRSpace as specified when the pose was obtained by calling XRFrame.getPose().

An XRRigidTransform which provides the position and orientation of the XRPose relative to the XRFrame to which this XRPose is aligned. This is the same pose that's returned by the frame's getPose() method.

This handler for the XRSession event select handles events for tracked pointers. It determines the targeted object by passing the event frame's pose into a function called findTargetUsingRay(), then dispatches the event differently depending on the user's handedness; this is done by comparing the value of the XRInputSource property handedness to a value in the variable user.handedness. If the source is a controller in the user's primary hand, a function is called on the targeted object called primaryAction(); otherwise, it calls the targeted object's offHandAction() function.

xrSession.addEventListener("select", (event) => {
  let source = event.inputSource;
  let frame = event.frame;
  let targetRayPose = frame.getPose(source.targetRaySpace, myRefSpace);
  let targetObject = findTargetUsingRay(targetRay.transform.matrix);

  if (source.targetRayMode === "tracked-pointer") {
    if (source.handedness === user.handedness) {
      targetObject.primaryAction();
    } else {
      targetObject.offHandAction();
    }
  }
});