To start taking advantage of the positional tracking of your hands, we simply need to parent the balloon prefab to the hand model. Our scene includes an XR Rig that contains not only the Main Camera that is positionally tracked with the player's head-mounted display, but it also contains a LeftHand Controller and RightHand Controller that are tracked with the player's hand controllers. Any game object that is a child of the hand controller object will be tracked along with it. To implement this, we will first modify the CreateBalloon function so that new balloons are attached to your hand controller and move with it as you move your hands. As we'll see, this introduces a new problem where the balloons are not necessarily positioned upright, so we'll fix that as well.
Parenting the balloon to your hand
The Balloon Controller will need to know which hand pressed the button and parent the balloon to that controller object. Specifically...
