UNIGRAFIX 2 relies on a new hidden surface algorithm based on the CROSS algorithm by Hamlin and Gear. In this algorithm visibility information is passed from vertices to edges, and through those to other vertices. At crossings of contour edges, visibility is reexamined. This algorithm is ideally suited for efficient computations of all visible polygons. A new option, -vf, has been added to Unigrafix, that will write all visible polygons to a specified file.