IFC 4.3.0.1 (IFC4X3_TC1)

8.15.3.10 IfcDerivedProfileDef

8.15.3.10.1 Semantic 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:

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.

Uniform
Figure 8.15.3.10.A

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.
Non uniform
Figure 8.15.3.10.B

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.
mirroring
Figure 8.15.3.10.C

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.)

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

8.15.3.10.2 Entity inheritance

8.15.3.10.3 Attributes

# Attribute Type Description
IfcProfileDef (4)
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.

2 ProfileName OPTIONAL 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.

HasExternalReference SET [0:?] OF IfcExternalReferenceRelationship FOR RelatedResourceObjects

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

HasProperties SET [0:?] OF IfcProfileProperties FOR ProfileDefinition

Additional properties of the profile, for example mechanical properties.

Click to show 4 hidden inherited attributes Click to hide 4 inherited attributes
IfcDerivedProfileDef (3)
3 ParentProfile IfcProfileDef

The parent profile provides the origin of the transformation.

4 Operator IfcCartesianTransformationOperator2D

Transformation operator applied to the parent profile.

5 Label OPTIONAL 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.

Table 8.15.3.10.D

8.15.3.10.4 Formal propositions

Name 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.

SELF\IfcProfileDef.ProfileType = ParentProfile.ProfileType
Table 8.15.3.10.E

8.15.3.10.5 Property sets

  • Pset_ProfileMechanical
    • MassPerLength
    • CrossSectionArea
    • Perimeter
    • MinimumPlateThickness
    • MaximumPlateThickness
    • CentreOfGravityInX
    • CentreOfGravityInY
    • ShearCentreZ
    • ShearCentreY
    • MomentOfInertiaY
    • MomentOfInertiaZ
    • MomentOfInertiaYZ
    • TorsionalConstantX
    • WarpingConstant
    • ShearDeformationAreaZ
    • ShearDeformationAreaY
    • MaximumSectionModulusY
    • MinimumSectionModulusY
    • MaximumSectionModulusZ
    • MinimumSectionModulusZ
    • TorsionalSectionModulus
    • ShearAreaZ
    • ShearAreaY
    • PlasticShapeFactorY
    • PlasticShapeFactorZ

8.15.3.10.6 Concept usage

Concept Usage Description
IfcProfileDef (1)
Property Sets for Profiles General

This concept can be applied to the following resources:

Click to show 1 hidden inherited concepts Click to hide 1 inherited concepts
Table 8.15.3.10.F

8.15.3.10.7 Formal representation

ENTITY IfcDerivedProfileDef
 SUPERTYPE OF (ONEOF
	(IfcMirroredProfileDef))
 SUBTYPE OF (IfcProfileDef);
	ParentProfile : IfcProfileDef;
	Operator : IfcCartesianTransformationOperator2D;
	Label : OPTIONAL IfcLabel;
 WHERE
	InvariantProfileType : SELF\IfcProfileDef.ProfileType = ParentProfile.ProfileType;
END_ENTITY;

8.15.3.10.8 References

8.15.3.10.9 Changelog

8.15.3.10.9.1 IFC4

  • where rule, InvariantProfileType
  • where rule, WR1