8.8.3.22 IfcGeometricSet
8.8.3.22.1 Semantic definition
The IfcGeometricSet is used for the exchange of shape representation consisting of (2D or 3D) points, curves, and surfaces, which do not have a topological structure (such as connected face sets or shells), are not tessellated and are not solid models (such as swept solids, CSG or Brep).
Definition from ISO/CD 10303-42: This entity is intended for the transfer of models when a topological structure is not available. Entity adapted from geometric_set defined in ISO 10303-42. New entity in IFC2x.8.8.3.22.2 Entity inheritance
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- IfcGeometricSet
- IfcAnnotationFillArea
- IfcBooleanResult
- IfcBoundingBox
- IfcCartesianPointList
- IfcCartesianTransformationOperator
- IfcCsgPrimitive3D
- IfcCurve
- IfcDirection
- IfcFaceBasedSurfaceModel
- IfcFillAreaStyleHatching
- IfcFillAreaStyleTiles
- IfcHalfSpaceSolid
- IfcLightSource
- IfcPlacement
- IfcPlanarExtent
- IfcPoint
- IfcSectionedSpine
- IfcSegment
- IfcShellBasedSurfaceModel
- IfcSolidModel
- IfcSurface
- IfcTessellatedItem
- IfcTextLiteral
- IfcVector
8.8.3.22.3 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. The inverse attribute LayerAssignments has been added. 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. The inverse attribute StyledByItem has been added. |
|
| Click to show 2 hidden inherited attributes Click to hide 2 inherited attributes | |||
| IfcGeometricSet (2) | |||
| 1 | Elements | SET [1:?] OF IfcGeometricSetSelect |
The geometric elements which make up the geometric set, these may be points, curves or surfaces; but are required to be of the same coordinate space dimensionality. |
| * | Dim | IfcDimensionCount |
This attribute is formally derived. The space dimensionality of this class, it is identical to the first element in the set. A where rule ensures that all elements have the same dimensionality. |
8.8.3.22.4 Formal propositions
| Name | Description |
|---|---|
| ConsistentDim |
All elements within a geometric set shall have the same dimensionality. |
|
|
8.8.3.22.5 Formal representation
ENTITY IfcGeometricSet
SUPERTYPE OF (ONEOF
(IfcGeometricCurveSet))
SUBTYPE OF (IfcGeometricRepresentationItem);
Elements : SET [1:?] OF IfcGeometricSetSelect;
DERIVE
Dim : IfcDimensionCount := Elements[1].Dim;
WHERE
ConsistentDim : SIZEOF(QUERY(Temp <* Elements |
Temp.Dim <> Elements[1].Dim))
= 0;
END_ENTITY;