PK_BODY_create_sheet_planar_o_t

struct PK_BODY_create_sheet_planar_o_s
    {
    int                    o_t_version;    --- version number (1)
    const int             *loops;          --- loop numbers (NULL)
    PK_AXIS1_sf_t          plane;          --- plane (XY plane)
    PK_AXIS2_sf_t          basis_set;      --- local coordinate system
                                           --- (world coordinate)
    };
typedef struct PK_BODY_create_sheet_planar_o_s PK_BODY_create_sheet_planar_o_t;



This options structure provides variable form input to
PK_BODY_create_sheet_planar.

Used in:

PK_BODY_create_sheet_planar

The boundaries of the planar sheet are defined by a given set of
'loops'.  If the 'loops' field is NULL (the default) then all the 'vectors'
lie on the same loop, this loop must be defined in a clockwise direction
(when viewed in the direction of the surface normal) so as to provide the
exterior boundary of the sheet.  Any body created must have exactly one loop
defined clockwise, all other loops being defined anticlockwise.

In the case where the 'loops' field is specified, for each vector in 'vectors',
the corresponding entry in 'loops' is the loop index for the loop to which the
vector belongs.  Thus the number of elements in each array must be equal.

If the 'loops' field of the options structure is NULL (the default), then the
given position vectors form a single loop which is the exterior of the sheet
body.

'plane' indicates the plane onto which all the position vectors in 'vectors'
are projected.

'plane' and 'vectors' are both defined in the local coordinate system.

The 'basis_set' positions and orientates the local coordinate system in the
world coordinate system.