IFC (IFC4X3_ADD2) under development IfcAdvancedBrepWithVoids Semantic definition

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.

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. Entity inheritance 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.

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.

Click to show 4 hidden inherited attributes Click to hide 4 inherited attributes
IfcAdvancedBrepWithVoids (1)
2 Voids SET [1:?] OF IfcClosedShell

No description available.

Table Formal propositions

Name Description

Each face of the voids within the advanced B-rep with voids shall be of type IfcAdvancedFace.

SIZEOF (QUERY (Vsh <* Voids |
  SIZEOF (QUERY (Afs <* Vsh.CfsFaces |
  )) = 0
)) = 0
Table Formal representation

ENTITY IfcAdvancedBrepWithVoids
 SUBTYPE OF (IfcAdvancedBrep);
	Voids : SET [1:?] OF IfcClosedShell;
	VoidsHaveAdvancedFaces : SIZEOF (QUERY (Vsh <* Voids |
  SIZEOF (QUERY (Afs <* Vsh.CfsFaces |
  )) = 0
)) = 0;
END_ENTITY; References

Edit on Github

Is this page difficult to understand? Let us know! Changelog IFC4

  • New resource