IfcBooleanResult

Semantic definitions at the entity

Entity definition

The IfcBooleanResult is the result of applying a Boolean operation to two operands being solids.

EXAMPLE 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.

NOTE 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.

NOTE Corresponding STEP type boolean_result defined in ISO 10303-42.

HISTORY New entity in IFC1.5.1.

Attribute definitions

#	Attribute	Type	Description	G
1	Operator	IfcBooleanOperator	The Boolean operator used in the operation to create the result.	X
2	FirstOperand	IfcBooleanOperand	The first operand to be operated upon by the Boolean operation.	X
3	SecondOperand	IfcBooleanOperand	The second operand specified for the operation.	X
	Dim :=FirstOperand.Dim	IfcDimensionCount	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.	X

Formal Propositions

Rule	Description
SameDim	The dimensionality of the first operand shall be the same as the dimensionality of the second operand.
FirstOperandClosed	If the FirstOperand is of type IfcTessellatedFaceSet it has to be a closed tessellation.
SecondOperandClosed	If the SecondOperand is of type IfcTessellatedFaceSet it has to be a closed tessellation.

Inherited definitions from supertypes

Entity inheritance

Attribute inheritance

#	Attribute	Type	Cardinality	Description	G
IfcRepresentationItem
	LayerAssignment	IfcPresentationLayerAssignment @AssignedItems	S[0:1]	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. 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.	X
	StyledByItem	IfcStyledItem @Item	S[0:1]	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.	X
IfcGeometricRepresentationItem
IfcBooleanResult
1	Operator	IfcBooleanOperator		The Boolean operator used in the operation to create the result.	X
2	FirstOperand	IfcBooleanOperand		The first operand to be operated upon by the Boolean operation.	X
3	SecondOperand	IfcBooleanOperand		The second operand specified for the operation.	X
	Dim :=FirstOperand.Dim	IfcDimensionCount		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.	X

Formal representations

XML Specification

 <xs:element name="IfcBooleanResult" type="ifc:IfcBooleanResult" substitutionGroup="ifc:IfcGeometricRepresentationItem" nillable="true"/>

 <xs:complexType name="IfcBooleanResult">

  <xs:complexContent>

   <xs:extension base="ifc:IfcGeometricRepresentationItem">

    <xs:sequence>

     <xs:element name="FirstOperand">

      <xs:complexType>

       <xs:group ref="ifc:IfcBooleanOperand"/>

      </xs:complexType>

     </xs:element>

     <xs:element name="SecondOperand">

      <xs:complexType>

       <xs:group ref="ifc:IfcBooleanOperand"/>

      </xs:complexType>

     </xs:element>

    </xs:sequence>

    <xs:attribute name="Operator" type="ifc:IfcBooleanOperator" use="optional"/>

   </xs:extension>

  </xs:complexContent>

 </xs:complexType>

EXPRESS Specification


ENTITY IfcBooleanResult

 SUPERTYPE OF(IfcBooleanClippingResult)

 SUBTYPE OF (IfcGeometricRepresentationItem);

  Operator : IfcBooleanOperator;

  FirstOperand : IfcBooleanOperand;

  SecondOperand : IfcBooleanOperand;

 DERIVE

  Dim : IfcDimensionCount := FirstOperand.Dim;

 WHERE

  SameDim : FirstOperand.Dim = SecondOperand.Dim;
  FirstOperandClosed : NOT('IFCGEOMETRICMODELRESOURCE.IfcTessellatedFaceSet' IN TYPEOF(FirstOperand)) OR (EXISTS(FirstOperand.Closed) AND FirstOperand.Closed);
  SecondOperandClosed : NOT('IFCGEOMETRICMODELRESOURCE.IfcTessellatedFaceSet' IN TYPEOF(SecondOperand)) OR (EXISTS(SecondOperand.Closed) AND SecondOperand.Closed);
END_ENTITY;

 EXPRESS-G diagram

	Boolesches Ergebnis
	Boolean Result
	Résultat booléen