1. A method, comprising: receiving, by a computer executing a non-tactile three dimensional (3D) user interface, a set of 3D coordinates representing a gesture performed by a limb of a user, wherein the limb is positioned within a field of view of a sensing device coupled to the computer and includes a joint, the set of 3D coordinates comprising first multiple points measured in a fixed 3D coordinate system local to the sensing device, the fixed 3D coordinate system having a first depth axis; upon the set of the 3D coordinates indicating that a motion of the joint has exceeded a specified threshold, transforming the first multiple points that indicate the limb to be moving along the first depth axis to corresponding second multiple points along a different, second depth axis local to the user; and applying the second multiple points in executing the non-tactile 3D user interface.