1. A method for detecting depth and direction when interfacing with a computer program, comprising: (a) capturing two or more stereo images presented in front of two or more corresponding image capture devices, each image capture device having a capture location in a coordinate space (b) synchronizing the image capture devices with a strobe signal that is visible to each image capture device; when a person is captured in the image, (c) identifying a first body part of the person in the image and assigning the first body part a first location in the coordinate space; (d) identifying a second body part of the person in the image and assigning the second body part a second location in coordinate space; and (e) identifying a relative position in coordinate space between the first location and the second location when viewed from the capture location, wherein the relative position includes a dimension of depth.