A system for computer graphic determination and display of a patient's anatomy, as from CT or MR scanning, and stored along with associated equipment in an object field including the patient's anatomy. A first digitizing camera structure produces a signal representative of its field-of-view which defines coordinates of index points in its field-of-view. A second digitizing camera structure produces similar output for an offset field-of-view. The two camera positions are defined with respect to the patient's anatomy so that the fields-of-view of the cameras include both the patient's anatomy and the equipment, but are taken from different directions. Index markers are for fixing points in the fields of view and accordingly locate equipment relative to said patient anatomy. The index markers are provided by variety of structures including, light sources in various forms as reflectors, diodes, and laser scanner structures to provide a visible grid, mesh or cloud of points.