Defined in File Ifc4x3_rc1.h
IfcFacetedBrep: public Ifc4x3_rc1::IfcManifoldSolidBrep¶
Definition from ISO/CD 10303-42:1992: A faceted B-rep is a simple form of boundary representation model in which all faces are planar and all edges are straight lines. Unlike the B-rep model, edges and vertices are not represented explicitly in the model but are implicitly available through the poly loop entity. A faceted B-rep has to meet the same topological constraints as the manifold solid B-rep.
NOTE 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.
NOTE Corresponding ISO 10303-42 entity: faceted_brep. Please refer to ISO/IS 10303-42:1994, p. 173 for the final definition of the formal standard. In the current IFC Release faceted B-rep with voids is represented by an own subtype and not defined via an implicit ANDOR supertype constraint as in ISO/IS 10303-42:1994. This change has been made due to the fact, that only ONEOF supertype constraint is allowed within the IFC data schema.
HISTORY New entity in IFC Release 1.0
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. That is, each Cartesian point shall be referenced by at least three polyloops.
Figure 257 illustrates use of IfcFacetedBrep for boundary representation models with planar surfaces only. The diagram shows the topological and geometric representation items that are used for faceted breps. Each IfcCartesianPoint, used within the IfcFacetedBrep shall be referenced three times by an IfcPolyLoop bounding a different IfcFace.
Figure 257 — Faceted B-rep
Subclassed by Ifc4x3_rc1::IfcFacetedBrepWithVoids