IFC 4.3.x development

8.8.3.2 IfcAdvancedBrepWithVoids

Change log

IFC4

added

IFC4X1

additionswhere_rulesVoidsHaveAdvancedFaces
deletionswhere_rulesVoidsHaveAdvancedFaces

IFC4X2

additionswhere_rulesVoidsHaveAdvancedFaces
deletionswhere_rulesVoidsHaveAdvancedFaces

IFC4X3_RC3

additionswhere_rulesVoidsHaveAdvancedFaces
deletionswhere_rulesVoidsHaveAdvancedFaces

8.8.3.2.1 Semantic definitions at the entity

The IfcAdvancedBrepWithVoids is a specialization of an advanced B-rep which contains one or more voids in its interior. The voids are represented as closed shells which are defined so that the shell normal point into the void.

NOTE  Entity adapted from advanced_brep_shape_representation defined in ISO 10303-42.

HISTORY  New entity in IFC4

Informal Propositions:

  1. Each void shell shall be disjoint from the outer shell and from every other void shell
  2. Each void shell shall be enclosed within the outer shell but not within any other void shell. In particular the outer shell is not in the set of void shells
  3. Each shell in the IfcManifoldSolidBrep shall be referenced only once.
  4. All the faces of all the shells in the IfcAdvancedBrep and the IfcAdvancedBrepWithVoids.Voids shall be of type IfcAdvancedFace.

8.8.3.2.1 Attributes

# Attribute Type Description
IfcRepresentationItem
LayerAssignmentSET [0:1] OF IfcPresentationLayerAssignment FOR AssignedItemsAssignment 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.
IfcGeometricRepresentationItem
IfcSolidModel
Dim INVALID The space dimensionality of this class, it is always 3.
IfcManifoldSolidBrep
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.
IfcAdvancedBrep
IfcAdvancedBrepWithVoids
2 Voids SET [1:?] OF IfcClosedShell

8.8.3.2.2 Entity inheritance

dot_inheritance IfcAdvancedBrepWithVoids IfcAdvancedBrepWithVoids IfcAdvancedBrep IfcAdvancedBrep IfcAdvancedBrepWithVoids->IfcAdvancedBrep IfcManifoldSolidBrep IfcManifoldSolidBrep IfcAdvancedBrep->IfcManifoldSolidBrep IfcFacetedBrep IfcFacetedBrep IfcFacetedBrep->IfcManifoldSolidBrep IfcSolidModel IfcSolidModel IfcManifoldSolidBrep->IfcSolidModel IfcSolidModel_children 4 more... IfcSolidModel_children->IfcSolidModel IfcGeometricRepresentationItem IfcGeometricRepresentationItem IfcSolidModel->IfcGeometricRepresentationItem IfcGeometricRepresentationItem_children 24 more... IfcGeometricRepresentationItem_children->IfcGeometricRepresentationItem IfcRepresentationItem IfcRepresentationItem IfcGeometricRepresentationItem->IfcRepresentationItem IfcRepresentationItem_children 3 more... IfcRepresentationItem_children->IfcRepresentationItem

8.8.3.2.3 Formal representations

ENTITY IfcAdvancedBrepWithVoids
 SUBTYPE OF (IfcAdvancedBrep);
	Voids : SET [1:?] OF IfcClosedShell;
 WHERE
	VoidsHaveAdvancedFaces : SIZEOF (QUERY (Vsh <* Voids |
  SIZEOF (QUERY (Afs <* Vsh.CfsFaces |
  (NOT ('IFC4X3_DEV_a1492713.IFCADVANCEDFACE' IN TYPEOF(Afs)))
  )) = 0
)) = 0;
END_ENTITY;