IfcBuild2Axes

Semantic definitions at the function

Function Definition

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

Formal representations

EXPRESS Specification


FUNCTION IfcBuild2Axes


  (RefDirection : IfcDirection)
    : LIST [2:2] OF IfcDirection;
LOCAL
  D : IfcDirection := NVL(IfcNormalise(RefDirection),
      IfcRepresentationItem() || IfcGeometricRepresentationItem () || IfcDirection([1.0,0.0]));
END_LOCAL;
  RETURN([D, IfcOrthogonalComplement(D)]);




END_FUNCTION;