struct PK_FACE_change_taper_o_s
    {
    int               o_t_version;  --- version number of option structure
    PK_EDGE_array_t   tapered_edges;--- tapered step edges
    PK_EDGE_array_t   normal_edges; --- normal step edges
    PK_taper_method_t method;       --- main face taper method
                                    --- (PK_taper_method_curve_c)
    };
typedef struct PK_FACE_change_taper_o_s PK_FACE_change_taper_o_t;


This structure contains taper-specific optional controls for PK_FACE_change


Description of fields:



tapered_edges          Edges which will give rise to tapered step faces.
                         These faces' surfaces will satisfy the taper
                         condition. Edges in this array should NOT also
                         appear in the normal_edges array.


normal_edges           Edges which will give rise to normal step faces.
                         These faces' surfaces are ruled surfaces normal
                         to the relevant original taper face.
                         These surfaces do NOT necessarily satisfy the taper
                         condition. Edges in this array should NOT also
                         appear in the tapered_edges array.


method                 Taper method to construct main taper faces' surfaces.
                         Values can be :
                             PK_taper_method_curve_c :   curve method
                             PK_taper_method_surface_c : surface method
                         The default value is PK_taper_method_curve_c.
                         For more details on taper surfaces refer to the
                         Definitions of Isocline Curves and Surfaces
                         section of the Functional Description.