{ .extDef}
NOTE Definition according to ISO/CD 10303-42:1992 This function returns two orthogonal directions. u[1] is in the direction of ref_direction and u[2] is perpendicular to u[1]. A default value of (1.0,0.0,0.0) is supplied for ref_direction if the input data is incomplete.
NOTE Function adapted from build_2axes defined in ISO 10303-42.
HISTORY New function in IFC1.5