8.8.3.5 IfcBooleanResult
8.8.3.5.1 Semantic definition
The IfcBooleanResult is the result of applying a Boolean operation to two operands being solids.
If the first operand is a block and the second operand is a solid cylinder of suitable dimensions and location, the boolean result produced with the difference operator would be a block with a circular hole. Definition according to ISO/CD 10303-42:1992 A Boolean result is the result of a regularized operation on two solids to create a new solid. Valid operations are regularized union, regularized intersection, and regularized difference. For purpose of Boolean operations, a solid is considered to be a regularized set of points. The final Boolean result depends upon the operation and the two operands. In the case of the difference operator the order of the operands is also significant. The operator can be either union, intersection or difference. The effect of these operators is described below: > * Union on two solids is the new solid that is the regularization of the set of all points that are in either the first operand or the second operand or in both. * Intersection on two solids is the new solid that is the regularization of the set of all points that are in both the first operand and the second operand. * The result of the difference operation on two solids is the regularization of the set of all points which are in the first operand, but not in the second operand. Corresponding STEP type boolean_result defined in ISO 10303-42. New entity in IFC1.5.1.8.8.3.5.2 Entity inheritance
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- IfcBooleanResult
- IfcAnnotationFillArea
- IfcBoundingBox
- IfcCartesianPointList
- IfcCartesianTransformationOperator
- IfcCsgPrimitive3D
- IfcCurve
- IfcDirection
- IfcFaceBasedSurfaceModel
- IfcFillAreaStyleHatching
- IfcFillAreaStyleTiles
- IfcGeometricSet
- IfcHalfSpaceSolid
- IfcLightSource
- IfcPlacement
- IfcPlanarExtent
- IfcPoint
- IfcSectionedSpine
- IfcSegment
- IfcShellBasedSurfaceModel
- IfcSolidModel
- IfcSurface
- IfcTessellatedItem
- IfcTextLiteral
- IfcVector
8.8.3.5.3 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 | |||
| IfcBooleanResult (4) | |||
| 1 | Operator | IfcBooleanOperator |
The Boolean operator used in the operation to create the result. |
| 2 | FirstOperand | IfcBooleanOperand |
The first operand to be operated upon by the Boolean operation. |
| 3 | SecondOperand | IfcBooleanOperand |
The second operand specified for the operation. |
| * | Dim | IfcDimensionCount |
This attribute is formally derived. The space dimensionality of this entity. It is identical with the space dimensionality of the first operand. A where rule ensures that both operands have the same space dimensionality. |
8.8.3.5.4 Formal propositions
| Name | Description |
|---|---|
| FirstOperandClosed |
If the FirstOperand is of type IfcTessellatedFaceSet it has to be a closed tessellation. |
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| SameDim |
The dimensionality of the first operand shall be the same as the dimensionality of the second operand. |
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| SecondOperandClosed |
If the SecondOperand is of type IfcTessellatedFaceSet it has to be a closed tessellation. |
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8.8.3.5.5 Examples
8.8.3.5.6 Formal representation
ENTITY IfcBooleanResult
SUPERTYPE OF (ONEOF
(IfcBooleanClippingResult))
SUBTYPE OF (IfcGeometricRepresentationItem);
Operator : IfcBooleanOperator;
FirstOperand : IfcBooleanOperand;
SecondOperand : IfcBooleanOperand;
DERIVE
Dim : IfcDimensionCount := FirstOperand.Dim;
WHERE
FirstOperandClosed : NOT('IFC4X3_DEV_bc7847cd.IFCTESSELLATEDFACESET' IN TYPEOF(FirstOperand)) OR (EXISTS(FirstOperand.Closed) AND FirstOperand.Closed);
SameDim : FirstOperand.Dim = SecondOperand.Dim;
SecondOperandClosed : NOT('IFC4X3_DEV_bc7847cd.IFCTESSELLATEDFACESET' IN TYPEOF(SecondOperand)) OR (EXISTS(SecondOperand.Closed) AND SecondOperand.Closed);
END_ENTITY;