There are six degrees of freedom that define the position and orientation of any object relative to a robot gripper. All six need to be determined for the robot to grasp the object in a uniquely specified manner. A robot vision system under development at the National Bureau of Standards is designed to measure all six of these degrees of freedom using two frames of video data taken sequentially from the same camera position. The system employs structured light techniques; in the first frame, the scene is illuminated by two parallel planes of light, and in the second frame by a point source of light.