IfcRepresentationMap

BACnet MVD

#### IfcRepresentationMap

Natural language names

| Ausgangsform für Transformation
| Representation Map

##### Semantic definitions at the entity

Entity definition

An IfcRepresentationMap defines the base definition (also referred to as block, cell or macro) called MappedRepresentation within the MappingOrigin. The MappingOrigin defines the coordinate system in which the MappedRepresentation is defined.

> NOTE Definition according to ISO/CD 10303-43:1992
> A representation map is the identification of a representation and a representation item in that representation for the purpose of mapping. The representation item defines the origin of the mapping. The representation map is used as the source of a mapping by a mapped item.

The RepresentationMap is used through an IfcMappeditem in one or several IfcShapeRepresentation's. An Cartesian transformation operator can be applied to transform the MappedRepresentation into the placement coordinate system of the shape representation. The transformation of the representation map is restricted to be a Cartesian transformation mapping (translation, rotation, mirroring and scaling).

> NOTE The definition of a mapping which is used to specify a new representation item comprises a representation map and a mapped item entity. Without both entities, the mapping is not fully defined. Two entities are specified to allow the same source representation to be mapped into multiple new representations.

> NOTE Entity adapted from representation_map defined in ISO 10303-43.

> HISTORY New entity in IFC2x.

Attribute definitions

# | Attribute | Type | Cardinality | Description | B
--- | --- | --- | --- | --- | ---
1 | MappingOrigin | IfcAxis2Placement |  | An axis2 placement that defines the position about which the mapped representation is mapped. | X | X
2 | MappedRepresentation | IfcRepresentation |  | A representation that is mapped to at least one mapped item. | X | X

HasShapeAspects

IfcShapeAspect
@PartOfProductDefinitionShape

S[0:?]

Reference to the shape aspect that represents part of the shape or its feature distinctively.

> IFC4 CHANGE Inverse attribute added.

X

| MapUsage | IfcMappedItem @MappingSource | S[0:?] |  |  | X

Formal Propositions

Rule | Description
--- | ---
ApplicableMappedRepr | Only representations of type IfcShapeRepresentation, or IfcTopologyRepresentation are allowed as MappedRepresentation.

##### Inherited definitions from supertypes

Entity inheritance
Attribute inheritance

# | Attribute | Type | Cardinality | Description | B
--- | --- | --- | --- | --- | ---
IfcRepresentationMap
1 | MappingOrigin | IfcAxis2Placement |  | An axis2 placement that defines the position about which the mapped representation is mapped. | X | X
2 | MappedRepresentation | IfcRepresentation |  | A representation that is mapped to at least one mapped item. | X | X

HasShapeAspects

IfcShapeAspect
@PartOfProductDefinitionShape

S[0:?]

Reference to the shape aspect that represents part of the shape or its feature distinctively.

> IFC4 CHANGE Inverse attribute added.

X

| MapUsage | IfcMappedItem @MappingSource | S[0:?] |  |  | X

##### Examples

- Mapped shape without transformation
- Mapped shape with transformation
- Mapped shape with multiple items

##### Formal representations

XML Specification
`<xs:element name="IfcRepresentationMap" type="ifc:IfcRepresentationMap" substitutionGroup="ifc:Entity" nillable="true"/>
<xs:complexType name="IfcRepresentationMap">
<xs:complexContent>
<xs:extension base="ifc:Entity">
<xs:sequence>
<xs:element name="MappingOrigin">
<xs:complexType>
<xs:group ref="ifc:IfcAxis2Placement"/>
</xs:complexType>
</xs:element>
<xs:element name="MappedRepresentation" type="ifc:IfcRepresentation" nillable="true"/>
</xs:sequence>
</xs:extension>
</xs:complexContent>
</xs:complexType>
`
EXPRESS Specification
`ENTITY IfcRepresentationMap;
MappingOrigin : IfcAxis2Placement;
MappedRepresentation : IfcRepresentation;
INVERSE
HasShapeAspects : SET [0:?] OF IfcShapeAspect FOR PartOfProductDefinitionShape;
MapUsage : SET [0:?] OF IfcMappedItem FOR MappingSource;
WHERE
ApplicableMappedRepr : 'IFCREPRESENTATIONRESOURCE.IfcShapeModel' IN TYPEOF(MappedRepresentation);
END_ENTITY;

EXPRESS-G diagram

`

References: IfcTypeProduct IfcMappedItem IfcRepresentation IfcProductRepresentationSelect

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