We describe two instances in which precise mechanical calibration of virtual environments equipment has been replaced by automated algorithmic calibration through software that encapsulates the hardware design and uses a goal-based approach to adjust calibration parameters. We describe a back-projection system for adjusting the assumed locations of beacons in a head-mounted display tracking system; the calculated errors in the navigation system are used to compute adjustments to the beacon positions to reduce such errors. In a second application, a piggyback headtracking/hand-tracking system is calibrated by a similar reduction of computed errors.