methods and apparatus render images of digital objects or prepare digital objects for subsequent processing . the method includes sorting data representative of positions of at least three vertices of polygons of a digital object , then determining whether the orientation of the vertices of each polygon from a specific reference point differs from the actual , or original , orientation of the vertices . such a determination may be made by generating an orientation decision variable based on the relative positions of the vertices and calculating a cross product term after the vertex data has been sorted . the cpt may also be used in other operations involving the polygon , such as in imparting appearance characteristics to the polygon . the method may be embodied as a computer program that controls the operation of a processor . processors , computers , and systems that practice the method are also contemplated .