8.8.3.26 IfcManifoldSolidBrep
ABSTRACT This definition may not be instantiated
8.8.3.26.1 Semantic definition
The IfcManifoldSolidBrep is a solid represented as a collection of connected surfaces that delimit the solid from the surrounding nonsolid.
Instances of type IfcManifoldSolidBrep shall be of type IfcFacetedBrep, using only IfcPolyLoop for the bounds of IfcFaceBound, or of type IfcAdvancedBrep, using only IfcAdvancedFace for the face geometry, and IfcEdgeCurve for the edges.
The Boundary Representation (Brep) of a manifold solid utilizes a graph of edges and vertices embedded in a connected, oriented, finite, closed two manifold surface. The embedded graph divides the surface into arcwise connected areas known as faces. The edges and vertices, therefore, form the boundaries of the face and the domain of a face does not include its boundaries. The embedded graph may be disconnected and may be a pseudo graph. The graph is labeled; that is, each entity in the graph has a unique identity. The geometric surface definition used to specify the geometry of a face shall be 2manifold embeddable in the plane within the domain of the face. In other words, it shall be connected, oriented, finite, nonselfintersecting, and of surface genus 0.
Faces do not intersect except along their boundaries. Each edge along the boundary of a face is shared by at most one other face in the assemblage. The assemblage of edges in the Brep do not intersect except at their boundaries (i.e., vertices). The geometry curve definition used to specify the geometry of an edge shall be arcwise connected and shall not self intersect or overlap within the domain of the edge. The geometry of an edge shall be consistent with the geometry of the faces of which it forms a partial bound. The geometry used to define a vertex shall be consistent with the geometry of the faces and edges of which it forms a partial bound.
The geometry used to define a vertex shall be consistent with the geometry of the faces and edges of which it forms a partial bound.
A Brep is represented by one or more closed shells which shall be disjoint. One shell, the outer, shall completely enclose all the other shells and no other shell may enclose a shell. The facility to define a Brep with one or more internal voids is provided by a subtype. The following version of the Euler formula shall be satisfied,
Informal proposition:
 The dimensionality of a manifold solid brep shall be 3.
 The extent of the manifold solid brep shall be finite and nonzero.
 All elements of the manifold solid brep shall have defined associated geometry.
 The shell normals shall agree with the Brep normal and point away from the solid represented by the Brep.
 Each face shall be referenced only once by the shells of the manifold solid brep.
 The Euler equation shall be satisfied for the boundary representation, where the genus term "shell term" us the sum of the genus values for the shells of the brep.
8.8.3.26.2 Entity inheritance

 IfcSolidModel
 IfcAnnotationFillArea
 IfcBooleanResult
 IfcBoundingBox
 IfcCartesianPointList
 IfcCartesianTransformationOperator
 IfcCsgPrimitive3D
 IfcCurve
 IfcDirection
 IfcFaceBasedSurfaceModel
 IfcFillAreaStyleHatching
 IfcFillAreaStyleTiles
 IfcGeometricSet
 IfcHalfSpaceSolid
 IfcLightSource
 IfcPlacement
 IfcPlanarExtent
 IfcPoint
 IfcSectionedSpine
 IfcSegment
 IfcShellBasedSurfaceModel
 IfcSurface
 IfcTessellatedItem
 IfcTextLiteral
 IfcVector
8.8.3.26.3 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. 

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. 

IfcSolidModel (1)  
*  Dim  IfcDimensionCount 
This attribute is formally derived.
The space dimensionality of this class, it is always 3. 
Click to show 3 hidden inherited attributes Click to hide 3 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. 
8.8.3.26.4 Formal representation
ENTITY IfcManifoldSolidBrep
ABSTRACT SUPERTYPE OF (ONEOF
(IfcAdvancedBrep
,IfcFacetedBrep))
SUBTYPE OF (IfcSolidModel);
Outer : IfcClosedShell;
END_ENTITY;