struct PK_facet_local_tolerances_s
    {
    double             curve_chord_tol;
    double             curve_chord_max;
    double             curve_chord_ang;
    double             surface_plane_tol;
    double             surface_plane_ang;
    };
typedef struct PK_facet_local_tolerances_s PK_facet_local_tolerances_t;


Local facet tolerances


The PK_facet_local_tolerances_t structure provides the following controls:
  CURVE TOLERANCES
    The following arguments control the curve tolerance values, measuring how
    closely a curved edge entity is approximated by a number of straight line
    chords.

    Three curve tolerance controls are provided:

    curve_chord_tol : the maximum chordal distance between a facet edge and
                      its original edge entity

    curve_chord_max : the maximum length of any facet edge which represents
                      part of an original edge entity

    curve_chord_ang : the maximum angle which is permitted between a facet
                      chord and its original edge entity

  SURFACE TOLERANCES
    The following arguments control surface tolerance values, measuring
    how closely any curved surface attached to a face is approximated
    by a facet mesh.

    Two surface tolerance controls are provided :

    surface_plane_tol : the maximum distance between the mid-plane
                        of a facet and its original face entity

    surface_plane_ang : the maximum angle (in radians) which is permitted
                        between the surface normals at any two positions
                        on the surface which lie within the facet boundary
                        (this is usually met but it is not guaranteed).

   To set one or more of these constraints, the value is set to a positive
   value.  If the value of a constraint is set to 0.0 the local tolerance of
   this constraint will not override the tolerance of the corresponding
   constraint previously supplied in the PK_TOPOL_facet_mesh_o_t.  If a
   particular constraint is set to 0.0 and the value of the corresponding
   constraint in the PK_TOPOL_facet_mesh_o_t is not supplied the default for
   this constraint will be used.