We have developed a set of algorithms to directly track planar surfaces and parametric surfaces under a calibrated stereo-rig. A movie demonstrating the planar surface tracking is here. A binary pixel mask is maintained which determines those pixel belonging to the plane (and with good texture); it is shown in red in the lower left of the video. The green vector being rendered is the plane's normal vector. Left is an image of the system that was built with our plane tracking routines to localize mobile robots. In the image, we show the real scene, the two walls that are being tracked (one in blue and one in red), and an overhead (orthogonal) projection of the reconstructed walls.