8.8.3.4 IfcBooleanClippingResult

AbV ⓘ

8.8.3.4.1 Semantic definition

A clipping result is defined as a special subtype of the general IfcBooleanResult. It constrains the operands and the operator of the Boolean result.

A clipping result is the Boolean difference between a swept solid and a half space solid, or between the result of the Boolean difference and a half space solid. Hence more than one difference operation can be applied to achieve the final Boolean result.

8.8.3.4.2 Entity inheritance

8.8.3.4.3 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. 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.
	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. IFC2x3-CHANGE The inverse attribute StyledByItem has been added.
Click to show 2 hidden 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. `FirstOperand.Dim` 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.

Table 8.8.3.4.A

8.8.3.4.4 Formal propositions

Name Description

FirstOperandType

The first operand of the Boolean clipping operation shall be either an IfcSweptAreaSolid or (in case of more than one clipping) an IfcBooleanResult.

 ('IFC4X3_DEV_738df036.IFCSWEPTAREASOLID' IN TYPEOF(FirstOperand)) OR 
('IFC4X3_DEV_738df036.IFCSWEPTDISCSOLID' IN TYPEOF(FirstOperand)) OR 
('IFC4X3_DEV_738df036.IFCBOOLEANCLIPPINGRESULT' IN TYPEOF(FirstOperand))

OperatorType

The Boolean operator for clipping is always "Difference".

Operator = DIFFERENCE

SecondOperandType

The second operand of the Boolean clipping operation shall be an IfcHalfSpaceSolid.

('IFC4X3_DEV_738df036.IFCHALFSPACESOLID' IN TYPEOF(SecondOperand))

Table 8.8.3.4.B

8.8.3.4.5 Formal representation

 ENTITY IfcBooleanClippingResult
 SUBTYPE OF (IfcBooleanResult);
 WHERE
	FirstOperandType : ('IFC4X3_DEV_738df036.IFCSWEPTAREASOLID' IN TYPEOF(FirstOperand)) OR 
('IFC4X3_DEV_738df036.IFCSWEPTDISCSOLID' IN TYPEOF(FirstOperand)) OR 
('IFC4X3_DEV_738df036.IFCBOOLEANCLIPPINGRESULT' IN TYPEOF(FirstOperand));
	OperatorType : Operator = DIFFERENCE;
	SecondOperandType : ('IFC4X3_DEV_738df036.IFCHALFSPACESOLID' IN TYPEOF(SecondOperand));
END_ENTITY;

8.8.3.4.6 References

IfcBooleanResult