Control apparatus includes an optical subsystem, which is configured to direct first light toward a scene that includes a hand of a user in proximity to a wall of a room and to receive the first light that is reflected from the scene, and to direct second light toward the wall so as to project an image of a control device onto the wall. A processor is configured to control the optical subsystem so as to generate, responsively to the received first light, a depth map of the scene, to process the depth map so as to detect a proximity of the hand to the wall in a location of the projected image, and to control electrical equipment in the room responsively to the proximity.