1. A method of generating an interpreted pattern of a mask layout feature, the mask layout including edges dissected into a plurality of segments, each segment having an evaluation point, the method comprising: identifying a two-dimensional segment; measuring an aerial image gradient at the evaluation point of the two-dimensional segment; determining a normal shift for the two-dimensional segment based on the aerial image gradient at the evaluation point; modifying a position of the segment using the normal shift; and saving the modified position as part of the interpreted pattern.