IFC 4.3.0.1 (IFC4X3) development

5.4.2.19 IfcReferentTypeEnum

5.4.2.19.1 Semantic definition

This enumeration defines the different types of referents.

5.4.2.19.2 Type values

Type Description
BOUNDARY

The referent represents where an administrative or maintenance boundary crosses the linear element being measured. This is typically the first time the boundary crosses the linear element. If the boundary runs along the linear element, it would be the point at which they first become collinear. The LRS should include specific rules about how boundaries are handled if this type of referent is permitted. If the linear element changes at the boundary as for a county route beginning at the county boundary, then the LRM is more correctly categorized as absolute.

INTERSECTION

The referent is the location of an intersection specified by the referent name. The intersection location is typically taken as the location of the intersection of the reference lines of the streets comprising the intersection and is, therefore, not necessarily precise or deterministic. Physical markers can be installed to remedy this. The LRS should include specific rules about how intersection locations are determined if this type of referent is permitted.

KILOPOINT

Kilo point

LANDMARK

The referent is the location of a physical landmark visible in the field.

MILEPOINT

Mile point

POSITION

Used to fully describe a linearly referenced location given by the linear element being measured (the IfcAlignment into which the IfcReferent is nested), the method of measurement (Pset_LinearReferencingMethod) and a measure value specified with a distance expression (Pset_DistanceExpression). If a linear referencing method is specified for the position, it overrides any linear referencing method specified for the alignment.”

REFERENCEMARKER

The reference marker is a notation referent, typically located in the right of way of the road, rail or other transportation system. Usually reference markers are initially spaced at a uniform distance along the linear element being measured, though subsequent re-alignments can result in uneven spacing between the markers.

STATION

Station

USERDEFINED

User defined.

NOTDEFINED

Undefined.

Table 5.4.2.19.A

5.4.2.19.3 Formal representation

TYPE IfcReferentTypeEnum = ENUMERATION OF
	(BOUNDARY
	,INTERSECTION
	,KILOPOINT
	,LANDMARK
	,MILEPOINT
	,POSITION
	,REFERENCEMARKER
	,STATION
	,USERDEFINED
	,NOTDEFINED);
END_TYPE;

5.4.2.19.4 References

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5.4.2.19.5 Changelog

  • item, BOUNDARY
  • item, INTERSECTION
  • item, LANDMARK
  • item, POSITION
  • item, REFERENCEMARKER