Defined in File Ifc4x1.h
IfcShapeRepresentation: public Ifc4x1::IfcShapeModel¶
The IfcShapeRepresentation represents the concept of a particular geometric representation of a product or a product component within a specific geometric representation context. The inherited attribute RepresentationType is used to define the geometric model used for the shape representation (for example, ‘SweptSolid’, or ‘Brep’), the inherited attribute RepresentationIdentifier is used to denote the part of the representation captured by the IfcShapeRepresentation (for example, ‘Axis’, ‘Body’).
Several representation identifiers for shape representation are included as predefined values for RepresentationIdentifier:
Box Bounding box as simplified 3D box geometry of an element
Annotation 2D annotations not representing elements
Axis 2D or 3D Axis, or single line, representation of an element
FootPrint 2D Foot print, or double line, representation of an element, projected to ground view
Surface 3D Surface representation, e.g. of an analytical surface, of an elementplane)
Body 3D Body representation, e.g. as wireframe, surface, or solid model, of an element
Lighting Representation of emitting light as a light source within a shape representation
Several representation types for shape representation are included as predefined values for RepresentationType:
Curve2D 2 dimensional curve
Curve3D 3 dimensional curve
Surface2D 2 dimensional surface (a region on ground view)
Surface3D 3 dimensional surface
GeometricSet points, curves, surfaces (2 or 3 dimensional)
GeometricCurveSet points, curves (2 or 3 dimensional)
Annotation2D points, curves (2 or 3 dimensional), hatches and text (2 dimensional)
SurfaceModel face based and shell based surface model
SolidModel including swept solid, Boolean results and Brep bodies more specific types are:
SweptSolid swept area solids, by extrusion and revolution, excluding tapered sweeps
AdvancedSweptSolid swept area solids created by sweeping a profile along a directrix, and tapered sweeps
Brep faceted Brep’s with and without voids
AdvancedBrep Brep’s based on advanced faces, with b-spline surface geometry, with and without voids
CSG Boolean results of operations between solid models, half spaces and Boolean results
Clipping Boolean differences between swept area solids, half spaces and Boolean results
some additional representation types are provided:
BoundingBox simplistic 3D representation by a bounding box
SectionedSpine cross section based representation of a spine curve and planar cross sections. It can represent a surface or a solid and the interpolations of the between the cross sections is not defined
LightSource light source with (depending on type) position, orientation, light colour, intensity and attenuation
MappedRepresentation representation based on mapped item(s), referring to a representation map. Note: it can be seen as an inserted block reference. The shape representation of the mapped item has a representation type declaring the type of its representation items.
Table 1: string values for the inherited attribute ‘RepresentationType’.
NOTE The definition of this entity relates to the ISO 10303 entity shape_representation. Please refer to ISO/IS 10303-41:1994 for the final definition of the formal standard.
HISTORY New entity in IFC Release 1.5.
IFC2x4 CHANGE The RepresentationType’s ‘Curve3D’, ‘Surface2D’, ‘Surface3D’, ‘AdvancedBrep’, ‘LightSource’, and the RepresentationIdentifier ‘Lighting’ have been added.