IfcGeometricCurveSet

BACnet MVD

#### IfcGeometricCurveSet

Natural language names

| Geometrische Gruppe - Punkte und Kurven
| Geometric Curve Set

##### Semantic definitions at the entity

Entity definition

The IfcGeometricCurveSet is used for the exchange of shape representation consisting of an collection of (2D or 3D) points and curves only.

> NOTE Definition according to ISO/CD 10303-42:1992
> A geometric curve set is a collection of two or three dimensional points and curves.

> NOTE Entity adapted from geometric_curve_set defined in ISO 10303-42.

> HISTORY New entity in IFC2x2.

Formal Propositions

Rule | Description
--- | ---
NoSurfaces | No surface shall be included in this geometric set.

##### Inherited definitions from supertypes

Entity inheritance
Attribute inheritance

# | Attribute | Type | Cardinality | Description | B
--- | --- | --- | --- | --- | ---
IfcRepresentationItem

LayerAssignment

IfcPresentationLayerAssignment
@AssignedItems

S[0:1]

Assignment of the representation item to a single or multiple layer(s). The LayerAssignments can override a LayerAssignments of the IfcRepresentation it is used within the list of Items.

> IFC2x3 CHANGE The inverse attribute LayerAssignments has been added.

> IFC4 CHANGE The inverse attribute LayerAssignment has been restricted to max 1. Upward compatibility for file based exchange is guaranteed.

X

StyledByItem

IfcStyledItem
@Item

S[0:1]

Reference to the IfcStyledItem that provides presentation information to the representation, e.g. a curve style, including colour and thickness to a geometric curve.

> IFC2x3 CHANGE The inverse attribute StyledByItem has been added.

X

X

IfcGeometricRepresentationItem
IfcGeometricSet
1 | Elements | IfcGeometricSetSelect | S[1:?] | The geometric elements which make up the geometric set, these may be points, curves or surfaces; but are required to be of the same coordinate space dimensionality. |  | X
| Dim :=Elements[1].Dim | IfcDimensionCount |  | The space dimensionality of this class, it is identical to the first element in the set. A where rule ensures that all elements have the same dimensionality. |  | X
IfcGeometricCurveSet

##### Formal representations

XML Specification
`<xs:element name="IfcGeometricCurveSet" type="ifc:IfcGeometricCurveSet" substitutionGroup="ifc:IfcGeometricSet" nillable="true"/>
<xs:complexType name="IfcGeometricCurveSet">
<xs:complexContent>
<xs:extension base="ifc:IfcGeometricSet"/>
</xs:complexContent>
</xs:complexType>
`
EXPRESS Specification
`ENTITY IfcGeometricCurveSet
SUBTYPE OF (IfcGeometricSet);
WHERE
NoSurfaces : SIZEOF(QUERY(Temp <* SELF\IfcGeometricSet.Elements |
'IFCGEOMETRYRESOURCE.IfcSurface' IN TYPEOF(Temp))) = 0;
END_ENTITY;

EXPRESS-G diagram

`

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