IfcDerivedProfileDef

BACnet MVD

#### IfcDerivedProfileDef

Natural language names

| abgeleitetes Profil
| Derived Profile Def
| Définition d'un profil dérivé

##### Semantic definitions at the entity

Entity definition

IfcDerivedProfileDef defines the profile by transformation from the parent profile. The transformation is given by a two dimensional transformation operator. Transformation includes translation, rotation, mirror and scaling. The latter can be uniform or non uniform. The derived profiles may be used to define swept surfaces, swept area solids or sectioned spines.

The transformation effects the position, rotation, mirroring or scale of the profile at the underlying coordinate system, i.e. the coordinate system defined by the swept surface or swept area solid that uses the profile definition. It is the xy plane of either:

- IfcSweptSurface.Position
- IfcSweptAreaSolid.Position

or in case of sectioned spines the xy plane of each list member of IfcSectionedSpine.CrossSectionPositions. The position and potential rotation of the ParentProfile within the underlying coordinate system is taken into consideration before applying the Cartesian transformation operator.

Note, if only mirroring is required, IfcMirroredProfileDef should be used instead.

> HISTORY New entity in IFC2x.

Figure 363 illustrates examples of derived profiles.

Parameter
The IfcDerivedProfileDef is defined using the IfcCartesianTransformationOperator2D (CTO), which is applied to the parent profile definition.

Example
The example shows an uniform scaling and a transformation of an IfcRectangleProfileDef to match the lower-left cardinal point. The attributes of the CTO are:

> `Axis1 = NIL (defaults to 1.,0.)
> Axis2 = NIL (defaults to 0.,1.)
> LocalOrigin = IfcCartesianPoint(<1/2 XDim>,<1/2 YDim>)
> Scale = 2.
> `

Note: The ParentProfile has a Position = IfcCartesianPoint(<1/2 XDim>,<1/2 YDim>) already.

Parameter
The IfcDerivedProfileDef is defined using non uniform transformationsby applying the IfcCartesianTransformationOperator2DnonUniform as a subtype of the 2D CTO.

Example
The example shows a non-uniform scaling and a translation of an IfcRectangleProfileDef to match the lower-left cardinal point. The attributes of the CTO are:

> `Axis1 = NIL (defaults to 1.,0.)
> Axis2 = NIL (defaults to 0.,1.)
> LocalOrigin = IfcCartesianPoint(0.,<1/2 YDim)
> Scale = 1.
> Scale2 = 2.
> `

Note: The ParentProfile has a Position = IfcCartesianPoint(<1/2 XDim>,<1/2 YDim>) already.

Parameter
The IfcDerivedProfileDef is defined using mirroring by applying the IfcCartesianTransformationOperator2D (CTO) to the parent profile.

Example
The example shows a mirroring of an IfcLShapeProfileDef to match the centre cardinal point. The attributes of the CTO are:

> `Axis1 = (-1.,0.)
> Axis2 = NIL (defaults to 0.,1.)
> LocalOrigin = IfcCartesianPoint(0.,0.)
> Scale = NIL (defaults to 1.)
> `

Note: The ParentProfile has a Position = IfcCartesianPoint(0.,0.).

This example is for illustration only. If the transformation results only in mirroring like shown in the example, then IfcMirroredProfileDef should be used instead of IfcDerivedProfileDef.

Note: The following color map applies:

- black coordinate axes show the underlying coordinate system of the swept surface, swept area solid, or sectioned spine
- red coordinate axes show the position coordinate system of the parent profile
- brown coordinate axes show the position coordinate system of the derived profile

Figure 363 — Derived profile

Attribute definitions

# | Attribute | Type | Cardinality | Description | B
--- | --- | --- | --- | --- | ---
3 | ParentProfile | IfcProfileDef |  | The parent profile provides the origin of the transformation. | X | X
4 | Operator | IfcCartesianTransformationOperator2D |  | Transformation operator applied to the parent profile. | X | X
5 | Label | IfcLabel | ? | The name by which the transformation may be referred to. The actual meaning of the name has to be defined in the context of applications. | X | X

Formal Propositions

Rule | Description
--- | ---
InvariantProfileType | The profile type of the derived profile shall be the same as the type of the parent profile, i.e. both shall be either AREA or CURVE.

##### Inherited definitions from supertypes

Entity inheritance
Attribute inheritance

# | Attribute | Type | Cardinality | Description | B
--- | --- | --- | --- | --- | ---
IfcProfileDef
1 | ProfileType | IfcProfileTypeEnum |  | Defines the type of geometry into which this profile definition shall be resolved, either a curve or a surface area. In case of curve the profile should be referenced by a swept surface, in case of area the profile should be referenced by a swept area solid. | X | X
2 | ProfileName | IfcLabel | ? | Human-readable name of the profile, for example according to a standard profile table. As noted above, machine-readable standardized profile designations should be provided in IfcExternalReference.ItemReference. | X | X

HasExternalReference

IfcExternalReferenceRelationship
@RelatedResourceObjects

S[0:?]

Reference to external information, e.g. library, classification, or document information, which is associated with the profile.

> IFC4 CHANGE New inverse attribute

X

HasProperties

IfcProfileProperties
@ProfileDefinition

S[0:?]

Additional properties of the profile, for example mechanical properties.

> IFC4 CHANGE New inverse attribute

X

IfcDerivedProfileDef
3 | ParentProfile | IfcProfileDef |  | The parent profile provides the origin of the transformation. | X | X
4 | Operator | IfcCartesianTransformationOperator2D |  | Transformation operator applied to the parent profile. | X | X
5 | Label | IfcLabel | ? | The name by which the transformation may be referred to. The actual meaning of the name has to be defined in the context of applications. | X | X

##### Formal representations

XML Specification
`<xs:element name="IfcDerivedProfileDef" type="ifc:IfcDerivedProfileDef" substitutionGroup="ifc:IfcProfileDef" nillable="true"/>
<xs:complexType name="IfcDerivedProfileDef">
<xs:complexContent>
<xs:extension base="ifc:IfcProfileDef">
<xs:sequence>
<xs:element name="ParentProfile" type="ifc:IfcProfileDef" nillable="true"/>
<xs:element name="Operator" type="ifc:IfcCartesianTransformationOperator2D" nillable="true" minOccurs="0"/>
</xs:sequence>
<xs:attribute name="Label" type="ifc:IfcLabel" use="optional"/>
</xs:extension>
</xs:complexContent>
</xs:complexType>
`
EXPRESS Specification
`ENTITY IfcDerivedProfileDef
SUPERTYPE OF(IfcMirroredProfileDef)
SUBTYPE OF (IfcProfileDef);
ParentProfile : IfcProfileDef;
Operator : IfcCartesianTransformationOperator2D;
Label : OPTIONAL IfcLabel;
WHERE
InvariantProfileType : SELF\IfcProfileDef.ProfileType = ParentProfile.ProfileType;
END_ENTITY;

EXPRESS-G diagram

`

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