[en] A method and a program for reproducing a geometrical picture of events on a 3-meter magnetic spectrometer with optical spark chambers are described. The process of restoration of an event registered on a photographic film comprises the following stages: automatic or semiautomatic numbering, restoration of coordinates of a spark in the spark-chamber space, finding of the reaction vertex and recalculation of the track parameters as applied to this point. The track parameters are recalculated by an iterative procedure involving the Newton method, and the equations of motion of a particle are integrated by the Runge-Kutta method. The problem of reproducing the geometrical picture of events has been solved by using a computer with the program ''Geometry''. To reduce computer time in solving the problem, the derivatives are calculated by formulas based on the model of the homogeneous magnetic field. At an average running speed of the M-220 computer amounting to 20.000 operations per second, about 7.5 sec are required to restore the geometrical picture of a single event