IFC 4.3.1.0 (IFC4X3_ADD1)

8.8.3.37 IfcShellBasedSurfaceModel

8.8.3.37.1 Semantic definition

An IfcShellBasedSurfaceModel represents the shape by a set of open or closed shells. The connected faces within the shell have a dimensionality 2 and are placed in a coordinate space of dimensionality 3.

Informal Propositions:

  1. The dimensionality of the shell based surface model is 2.
  2. The shells shall not overlap or intersect except at common faces, edges or vertices.

8.8.3.37.2 Entity inheritance

8.8.3.37.3 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.

Click to show 2 hidden inherited attributes Click to hide 2 inherited attributes
IfcShellBasedSurfaceModel (2)
1 SbsmBoundary SET [1:?] OF IfcShell

No description available.

* Dim IfcDimensionCount

This attribute is formally derived.

3

The space dimensionality of this class, it is always 3.

Table 8.8.3.37.A

8.8.3.37.4 Formal representation

ENTITY IfcShellBasedSurfaceModel
 SUBTYPE OF (IfcGeometricRepresentationItem);
	SbsmBoundary : SET [1:?] OF IfcShell;
 DERIVE
	 Dim : IfcDimensionCount := 3;
END_ENTITY;

8.8.3.37.5 References