Aspects of the present disclosure relate to controlling the functions of various devices based on spatial relationships. In one example, a system may include a depth and visual camera and a computer (networked or local) for processing data from the camera. The computer may be connected (wired or wirelessly) to any number of devices that can be controlled by the system. A user may use a mobile device to define a volume of space relative to the camera. The volume of space may then be associated with a controlled device as well as one or more control commands. When the volume of space is subsequently occupied, the one or more control commands may be used to control the controlled device. In this regard, a user may switch a device on or off, increase volume or speed, etc. simply by occupying the volume of space.