8.8.3.18 IfcFacetedBrep

RV ⓘ

AbV ⓘ

8.8.3.18.1 Semantic definition

The IfcFacetedBrep is a manifold solid brep with the restriction that all faces are planar and bounded polygons.

faceted brep instantiation — Figure 8.8.3.18.A — Diagram showing the use of *IfcFacetedBrep*

The faceted B-rep has been introduced in order to support the larger number of systems that allow boundary type solid representations with planar surfaces only.

Informal Propositions

All the bounding loops of all the faces of all the shells in the IfcFacetedBrep shall be of type IfcPolyLoop.
All vertices shall be referenced by all polyloops, sharing the vertex. I.e., each Cartesian point shall be references by at least three polyloops.

8.8.3.18.2 Entity inheritance

8.8.3.18.3 Attributes

#	Attribute	Type	Description
IfcRepresentationItem (2)
	LayerAssignment	SET [0:1] OF IfcPresentationLayerAssignment FOR AssignedItems	Assignment of the representation item to a single or multiple layer(s). The LayerAssignments can override a LayerAssignments of the IfcRepresentation it is used within the list of Items. IFC2x3-CHANGE The inverse attribute LayerAssignments has been added. IFC4-CHANGE The inverse attribute LayerAssignment has been restricted to max 1. Upward compatibility for file based exchange is guaranteed.
	StyledByItem	SET [0:1] OF IfcStyledItem FOR Item	Reference to the IfcStyledItem that provides presentation information to the representation, e.g. a curve style, including colour and thickness to a geometric curve. IFC2x3-CHANGE The inverse attribute StyledByItem has been added.
IfcSolidModel (1)
*	Dim	IfcDimensionCount	This attribute is formally derived. `3` The space dimensionality of this class, it is always 3.
Click to show 3 hidden inherited attributes
IfcManifoldSolidBrep (1)
1	Outer	IfcClosedShell	A closed shell defining the exterior boundary of the solid. The shell normal shall point away from the interior of the solid.

Table 8.8.3.18.D

8.8.3.18.4 Examples

Figure 8.8.3.18.B

Brep Model
Figure 8.8.3.18.C

Basin Faceted Brep

8.8.3.18.5 Formal representation

 ENTITY IfcFacetedBrep
 SUPERTYPE OF (ONEOF
	(IfcFacetedBrepWithVoids))
 SUBTYPE OF (IfcManifoldSolidBrep);
END_ENTITY;

	ENTITY IfcFacetedBrep
	SUPERTYPE OF (ONEOF
	(IfcFacetedBrepWithVoids))
	SUBTYPE OF (IfcManifoldSolidBrep);
	END_ENTITY;

8.8.3.18 IfcFacetedBrep

8.8.3.18.1 Semantic definition

8.8.3.18.2 Entity inheritance

8.8.3.18.3 Attributes

8.8.3.18.4 Examples

8.8.3.18.5 Formal representation

8.8.3.18.6 References