Methods and systems are provided useful in various procedures, including hair harvesting and implantation, and further including computer-implemented and/or robotic hair transplantation. Methodologies are provided which enable a tool, such as a hair harvesting or a hair implantation tool, to proceed at least under a partial computer control in a selected direction of travel along a donor or recipient area of the patient, as well as changing direction of travel based on desired harvesting and/or implantation criteria.