A user interface system includes a plane registration module configured to identify a first plane within an environment, and a gesture and posture recognition (GPR) module configured to observe a first allocation gesture, a second allocation gesture, a first modal gesture, a second modal gesture, and a third modal gesture within the environment. A region definition module is configured to determine a first region comprising a first portion of the first plane based on the first allocation gesture, and to determine a second region comprising a second portion of the first plane based on the second allocation gesture. A mode determination module is configured to determine different interaction modes for the various regions. A visual feedback module is configured to provide visual feedback associated with a parameter of the first region.