﻿ IfcBooleanResult

#### IfcBooleanResult

Natural language names
 Boolesches Ergebnis Boolean Result Résultat booléen
##### 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
#AttributeTypeCardinalityDescription G
1OperatorIfcBooleanOperator The Boolean operator used in the operation to create the result.X
2FirstOperandIfcBooleanOperand The first operand to be operated upon by the Boolean operation.X
3SecondOperandIfcBooleanOperand The second operand specified for the operation.X
Dim
:=FirstOperand.Dim
IfcDimensionCountThe 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
RuleDescription
SameDimThe dimensionality of the first operand shall be the same as the dimensionality of the second operand.
FirstOperandClosedIf the FirstOperand is of type IfcTessellatedFaceSet it has to be a closed tessellation.
SecondOperandClosedIf the SecondOperand is of type IfcTessellatedFaceSet it has to be a closed tessellation.
##### Inherited definitions from supertypes
Entity inheritance
Attribute inheritance
#AttributeTypeCardinalityDescriptionG
IfcRepresentationItem
LayerAssignmentIfcPresentationLayerAssignment
@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
StyledByItemIfcStyledItem
@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
1OperatorIfcBooleanOperator The Boolean operator used in the operation to create the result.X
2FirstOperandIfcBooleanOperand The first operand to be operated upon by the Boolean operation.X
3SecondOperandIfcBooleanOperand The second operand specified for the operation.X
Dim
:=FirstOperand.Dim
IfcDimensionCountThe 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 ```

References: IfcBooleanOperand IfcCsgSelect