Abstract: Method and Apparatus for guiding an operation effector such as a laser cutter to effect an operation along a path on a patterned material using machine vision. The machine vision is used to make a map of a repeat of the pattern, a path is defined on the map by drawing a line on an area image map of the repeat of the pattern, the material and operation effector are moved relatively along the direction of pattern repeat, a line scan camera scans the material during a relative movement between the camera and the patterned material and a scanning image is compared with the map to determine the relative positions of the material and the operation effector, and the operation effector is guided to effect the operation at a position on the material corresponding to the path defined on the map.