1. A method of performing an action with a processor, comprising: generating, using the processor, a three-dimensional desktop environment and projecting the three-dimensional desktop environment into a real space; propagating an ultrasonic pulse into the real space; receiving a reflection of the ultrasonic pulse from a user object located within the real space; determining a user action of the user object using the ultrasonic pulse and the reflected ultrasonic pulse; and performing the action with the processor based on the determined user action.