Class Ifc4::IfcLoop¶
Defined in File Ifc4.h
Nested Relationships¶
This class is a nested type of Struct Ifc4.
Inheritance Relationships¶
Base Type¶
public Ifc4::IfcTopologicalRepresentationItem
(Class Ifc4::IfcTopologicalRepresentationItem)
Derived Types¶
public Ifc4::IfcEdgeLoop
(Class Ifc4::IfcEdgeLoop)public Ifc4::IfcPolyLoop
(Class Ifc4::IfcPolyLoop)public Ifc4::IfcVertexLoop
(Class Ifc4::IfcVertexLoop)
Class Documentation¶

class
Ifc4
::
IfcLoop
: public Ifc4::IfcTopologicalRepresentationItem¶ Definition from ISO/CD 1030342:1992: A loop is a topological entity constructed from a single vertex, or by stringing together connected (oriented) edges, or linear segments beginning and ending at the same vertex. It is typically used to bound a face lying on a surface. A loop has dimensionality of 0 or 1. The domain of a 0dimensional loop is a single point. The domain of a 1dimensional loop is a connected, oriented curve, but need not to be manifold. As the loop is a circle, the location of its beginning/ending point is arbitrary. The domain of the loop includes its bounds, an 0 ≤ Ξ < ∞.
A loop is represented by a single vertex, or by an ordered collection of oriented edges, or by an ordered collection of points. A loop is a graph, so M and the graph genus Gl may be determined by the graph traversal algorithm. Since M = 1, the Euler equation (1) reduces in this case to
where V and El are the number of unique vertices and oriented edges in the loop and Gl is the genus of the loop.
NOTE
Corresponding ISO 10303 entity: loop, the following subtypes have been incorporated into IFC: poly_loop as IfcPolyLoop, vertex_loop as IfcVertexLoop, edge_loop as IfcEdgeLoop. Please refer to ISO/IS 1030342:1994, p. 136 for the final definition of the formal standard.HISTORY New Entity in IFC2x. Informal propositions:
A loop has a finite extent. A loop describes a closed (topological) curve with coincident start and end vertices.
Subclassed by Ifc4::IfcEdgeLoop, Ifc4::IfcPolyLoop, Ifc4::IfcVertexLoop
Public Types

typedef IfcTemplatedEntityList<IfcLoop>
list
¶

typedef IfcTemplatedEntityList<IfcLoop>