IFC (IFC4X3_ADD1) development IfcCoordinateReferenceSystem

AbRV ⓘ
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ABSTRACT This definition may not be instantiated Semantic definition

The IfcCoordinateReferenceSystem is a definition of a coordinate reference system by means of qualified identifiers only. The interpretation of the identifier is expected to be well-known to the receiving software.

The unambiguous identifier by which the coordinate reference system is know, is stored in the Name attribute. Well defined identifiers include the geodetic and often also the vertical datum. In these cases the GeodeticDatum and the VerticalDatum can be omitted. Entity inheritance Attributes

# Attribute Type Description
IfcCoordinateReferenceSystem (4)
1 Name OPTIONAL IfcLabel

Name by which the coordinate reference system is identified.

2 Description OPTIONAL IfcText

Informal description of this coordinate reference system

Example for ellipsoid: ELLIPSOID[,,,]

HasCoordinateOperation SET [0:1] OF IfcCoordinateOperation FOR SourceCRS

Indicates conversion between coordinate systems. In particular it refers to an IfcCoordinateOperation between this coordinate reference system, and another Geographic coordinate reference system.

WellKnownText SET [0:1] OF IfcWellKnownText FOR CoordinateReferenceSystem

Well Known Text (WKT) definition for this Coordinate Reference System inversely associated as a IfcWellKnownText entity.

Table Formal propositions

Name Description

No description available.

(HIINDEX(WellKnownText) = 1) OR EXISTS(Name)
Table Formal representation

ENTITY IfcCoordinateReferenceSystem
	Name : OPTIONAL IfcLabel;
	Description : OPTIONAL IfcText;
	HasCoordinateOperation : SET [0:1] OF IfcCoordinateOperation FOR SourceCRS;
	WellKnownText : SET [0:1] OF IfcWellKnownText FOR CoordinateReferenceSystem;
	NameOrWKT : (HIINDEX(WellKnownText) = 1) OR EXISTS(Name);
END_ENTITY; References

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Is this page difficult to understand? Let us know! Changelog IFC4

  • New resource IFC4.3_DEV_d297a43

  • inverse attribute, WellKnownText
  • where rule, NameOrWKT
  • attribute, GeodeticDatum
  • attribute, VerticalDatum
  • attribute Name optional, Changed from "False" to "True"