IfcCurveBoundedPlane

BACnet MVD

#### IfcCurveBoundedPlane

Natural language names

| Durch Kurven begrenzte Ebene
| Curve Bounded Plane

##### Semantic definitions at the entity

Entity definition

The IfcCurveBoundedPlane is a parametric planar surface with curved boundaries defined by one or more boundary curves. The bounded plane is defined to be the portion of the basis surface in the direction of N x T from any point on the boundary, where N is the surface normal and T the boundary curve tangent vector at this point. The region so defined shall be arcwise connected.

The BasisSurface is an IfcPlane that establishes the position coordinate system by SELF\IfcElementarySurface.Position. The OuterBoundary and the InnerBoundaries (if provided) shall lie on the surface of IfcPlane. The outer and inner boundary curves shall be defined using the u, and v values provided by parameterization of the BasisSurface as their x, and y coordinate values.

> NOTE Entity defined in analogy to curve_bounded_surface defined in ISO 10303-42.

> HISTORY New entity in IFC1.5

> IFC2x CHANGE The data type of the attribute OuterBoundary and InnerBoundaries has been changed from Ifc2DCompositeCurve to supertype IfcCurve.

Attribute definitions

# | Attribute | Type | Cardinality | Description | B
--- | --- | --- | --- | --- | ---
1 | BasisSurface | IfcPlane |  | The surface to be bound. |  | X
2 | OuterBoundary | IfcCurve |  | The outer boundary of the surface. |  | X
3 | InnerBoundaries | IfcCurve | S[0:?] | An optional set of inner boundaries. They shall not intersect each other or the outer boundary. |  | X

##### 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
IfcSurface

Dim
:=3

IfcDimensionCount

The space dimensionality of IfcSurface. It is always a three-dimensional geometric representation item.

> IFC4 CHANGE Derived attribute promoted from subtypes.

X

X

IfcBoundedSurface
IfcCurveBoundedPlane
1 | BasisSurface | IfcPlane |  | The surface to be bound. |  | X
2 | OuterBoundary | IfcCurve |  | The outer boundary of the surface. |  | X
3 | InnerBoundaries | IfcCurve | S[0:?] | An optional set of inner boundaries. They shall not intersect each other or the outer boundary. |  | X

##### Formal representations

XML Specification
`<xs:element name="IfcCurveBoundedPlane" type="ifc:IfcCurveBoundedPlane" substitutionGroup="ifc:IfcBoundedSurface" nillable="true"/>
<xs:complexType name="IfcCurveBoundedPlane">
<xs:complexContent>
<xs:extension base="ifc:IfcBoundedSurface">
<xs:sequence>
<xs:element name="BasisSurface" type="ifc:IfcPlane" nillable="true"/>
<xs:element name="OuterBoundary" type="ifc:IfcCurve" nillable="true"/>
<xs:element name="InnerBoundaries">
<xs:complexType>
<xs:sequence>
<xs:element ref="ifc:IfcCurve" minOccurs="0" maxOccurs="unbounded"/>
</xs:sequence>
<xs:attribute ref="ifc:itemType" fixed="ifc:IfcCurve"/>
<xs:attribute ref="ifc:cType" fixed="set"/>
<xs:attribute ref="ifc:arraySize" use="optional"/>
</xs:complexType>
</xs:element>
</xs:sequence>
</xs:extension>
</xs:complexContent>
</xs:complexType>
`
EXPRESS Specification
`ENTITY IfcCurveBoundedPlane
SUBTYPE OF (IfcBoundedSurface);
BasisSurface : IfcPlane;
OuterBoundary : IfcCurve;
InnerBoundaries : SET [0:?] OF IfcCurve;
END_ENTITY;

EXPRESS-G diagram

`

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