from buildingSMART: The IfcProfileDef
is the supertype of all definitions of standard and arbitrary profiles
within IFC. It is used to define a standard set of commonly used
profiles by their parameters or by their explicit curve geometry. Those
profile definitions are used within the geometry and geometric model
resource to create either swept surfaces, swept area solids, or
The purpose of the profile definition within the swept surfaces or swept area solids is to define a uniform cross section being swept:
The purpose fo the profile definition within the sectioned spine is to define a varying cross sections at several positions along a spine curve. The subtype IfcDerivedProfileDef is particularly suited to provide the consecutive profiles to be based on transformations of the start profile and thus maintaining the identity of vertices and edges.
NOTE: Subtypes of the IfcProfileDef contain parameterized profiles (as subtypes of IfcParameterizedProfileDef) which establish their own 2D position coordinate system, profiles given by explicit curve geometry (either open or closed profiles) and two special types for composite profiles and derived profiles, based on a 2D Cartesian transformation.
An IfcProfileDef is treated as bounded area if it is used within swept area solids. In this case, the inside of the profile is part of the profile. The attribute ProfileType is set to AREA. An IfcProfileDef is treated as a curve if it is used within swept surfaces. In this case, the inside of the profile (if the curve is closed) is not part of the profile. The attribute ProfileType is set to CURVE. The optional attribute ProfileName can be used to designate a standard profile type as e.g. given in profile tables for steel profiles.
HISTORY: New class in IFC Release 1.5, the capabilities have been extended in IFC Release 2x. Profiles can now support swept surfaces and swept area solids with inner boundaries. It had been renamed from IfcAttDrivenProfileDef.
Note: The parameterized profile definition defines a 2D position coordinate system, relative to the underlying coordinate system of the IfcProfileDef.
In the later use of the IfcProfileDef
within the swept surface or swept area solid, e.g. the IfcExtrudedAreaSolid
(here used as an example), the profile boundaries (here based on the 2D
position coordinate system of IfcParameterizedProfileDef)
are placed within the xy plane of the 3D position coordinate system of
the swept surface or swept area solid.
The profile is inserted into the underlying coordinate system either:
Use cases:Results of the different usage of the ProfileType attribute are demonstrated here. The ProfileType defines whether the inside (the bounded area) is part of the profile definition (Area) or not (Curve).
ProfileType = AREA
ProfileType = CURVE
Table: Resulting area or curve depending on ProfileType
|ProfileType||:||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.|
|ProfileName||:||Name of the profile type according to some standard profile table.|