PK_BOX_t    


struct PK_BOX_s
    {
    double coord[6];
    };
typedef struct PK_BOX_s PK_BOX_t;



This structure represents a rectangular box aligned with the world coordinate
axes.


The components are as follows:

    `coord[0]'   minimum X
    `coord[1]'   minimum Y
    `coord[2]'   minimum Z
    `coord[3]'   maximum X
    `coord[4]'   maximum Y
    `coord[5]'   maximum Z