An acoustic field may be produced from a transducer array having known relative positions and orientations In this acoustic field, one or more control points may be defined. An amplitude may be assigned to the control point. Mid-air haptic effect for a virtual object on a human body part may be generated by moving the control point in a single closed curve comprising a plurality of curve segments. The single closed curve traverses at least one location where the human body part intersects with the virtual object. Additionally, a user may interact with virtual three-dimensional content using the user's hands while a tracking system monitoring the user's hands, a physics engine updates the properties of the virtual three-dimensional content and a haptic feedback system provides haptic information to the user.