IFC (IFC4X3_ADD2) under development IfcTrapeziumProfileDef

DEPRECATED This definition will be removed in a future major release of this standard Semantic definition

IfcTrapeziumProfileDef defines a trapezium as the profile definition used by the swept surface geometry or the swept area solid. It is given by its Top X and Bottom X extent and its Y extent as well as by the offset of the Top X extend, and placed within the 2D position coordinate system, established by the Position attribute. It is placed centric within the position coordinate system, that is, in the center of the bounding box.

Figure illustrates parameters of the trapezium profile definition.

trapezium profile
Figure — Trapezium profile


The parameterized profile defines its own position coordinate system. The underlying coordinate system is 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.

By using offsets of the position location, the parameterized profile can be positioned centric (using x,y offsets = 0.), or at any position relative to the profile. Explicit coordinate offsets are used to define cardinal points (e.g. upper-left bound).


The IfcTrapeziumProfileDef is defined within the position coordinate system, where the BottomDim defines the length measure for the bottom line (half along the positive x-axis) and the YDim defines the length measure for the parallel distance of bottom and top line (half along the positive y-axis). The top line starts with a distance of TopXOffset from -BottomLine/2,YDim (which can be negative, zero, or positive) and has a length of TopXDim along the positive x-axis. Entity inheritance 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.

IfcParameterizedProfileDef (1)
3 Position OPTIONAL IfcAxis2Placement2D

Position coordinate system of the parameterized profile definition. If unspecified, no translation and no rotation is applied.

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IfcTrapeziumProfileDef (4)
4 BottomXDim IfcPositiveLengthMeasure

The extent of the bottom line measured along the implicit x-axis.

5 TopXDim IfcPositiveLengthMeasure

The extent of the top line measured along the implicit x-axis.

6 YDim IfcPositiveLengthMeasure

The extent of the distance between the parallel bottom and top lines measured along the implicit y-axis.

7 TopXOffset IfcLengthMeasure

Offset from the beginning of the top line to the bottom line, measured along the implicit x-axis.

Table 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 Concept usage

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

This concept can be applied to the following resources:

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Table Formal representation

ENTITY IfcTrapeziumProfileDef
 SUBTYPE OF (IfcParameterizedProfileDef);
	BottomXDim : IfcPositiveLengthMeasure;
	TopXDim : IfcPositiveLengthMeasure;
	YDim : IfcPositiveLengthMeasure;
	TopXOffset : IfcLengthMeasure;
END_ENTITY; References

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