IFC 4.3.x development

8.7.3.8 IfcConnectionPointGeometry

8.7.3.8.1 Semantic definitions at the entity

IfcConnectionPointGeometry is used to describe the geometric constraints that facilitate the physical connection of two objects at a point (here IfcCartesianPoint) or at an vertex with point coordinates associated. It is envisioned as a control that applies to the element connection relationships.

EXAMPLE  The connection relationship between two path based elements (like a column and a beam) has a geometric constraint which describes the connection points by a PointOnRelatingElement for the column and a PointOnRelatedElement for the beam. The exact usage of the IfcConnectionPointGeometry is further defined in the geometry use sections of the elements that use it.

The IfcPoint (or the IfcVertexPoint with an associated IfcPoint) at the PointOnRelatingElement attribute defines the point where the basic geometry items of the connected elements connect. The point coordinates are provided within the local coordinate system of the RelatingElement, as specified at the IfcRelConnectsSubtype that utilizes the IfcConnectionPointGeometry. Optionally, the same point coordinates can also be provided within the local coordinate system of the RelatedElement by using the PointOnRelatedElement attribute. If both point coordinates are not identical within a common parent coordinate system (ultimately within the world coordinate system), the subtype IfcConnectionPointEccentricity shall be used.

NOTE  If the point connection has an offset (if the two points or vertex points at the relating and related element do not physically match), the subtype IfcConnectionPointEccentricity shall be used.

HISTORY  New entity in IFC1.5.

IFC2x CHANGE  Renamed from IfcPointConnectionGeometry.

IFC2x3 CHANGE  The provision of topology with associated geometry, IfcVertexPoint, is enabled by using the IfcPointOrVertexPoint.

8.7.3.8.1 Attributes

#Attribute Type Description
IfcConnectionGeometry
IfcConnectionPointGeometry
1PointOnRelatingElementIfcPointOrVertexPoint Point at which the connected object is aligned at the relating element, given in the LCS of the relating element.
2PointOnRelatedElement OPTIONAL IfcPointOrVertexPointPoint at which connected objects are aligned at the related element, given in the LCS of the related element. If the information is omitted, then the origin of the related element is used.

8.7.3.8.2 Entity inheritance

dot_inheritance IfcConnectionPointEccentricity IfcConnectionPointEccentricity IfcConnectionPointGeometry IfcConnectionPointGeometry IfcConnectionPointEccentricity->IfcConnectionPointGeometry IfcConnectionGeometry IfcConnectionGeometry IfcConnectionPointGeometry->IfcConnectionGeometry IfcConnectionGeometry_children 3 more... IfcConnectionGeometry_children->IfcConnectionGeometry

8.7.3.8.3 Formal representations

ENTITY IfcConnectionPointGeometry
 SUPERTYPE OF (ONEOF
	(IfcConnectionPointEccentricity))
 SUBTYPE OF (IfcConnectionGeometry);
	PointOnRelatingElement : IfcPointOrVertexPoint;
	PointOnRelatedElement : OPTIONAL IfcPointOrVertexPoint;
END_ENTITY;