A system (40) for processing a workpiece includes a support surface (88) for supporting a workpiece (44). The system (40) includes a processing tool (92) movable with respect to a processing path. The system (40) includes a sensor carriage (408) movable along a scan axis and having a light source (476, 515, 550, 586) located to emit a light beam at an angle to the scan axis onto a target surface of a workpiece (44), and a camera (484, 522, 558, 594) configured to record location data of the light beam on a target surface of a workpiece (44) as the sensor carriage (408) moves along the scan axis. The system (40) includes a control system for generating a three-dimensional point representation of a workpiece surface from the light beam location data, to control movement of the processing tool (92) based on the three-dimensional point representation of a workpiece (44).