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IfcBooleanClippingResult

Definition from IAI: A Clipping result is defined as a special subtype of the general Boolean result (IfcBooleanResult). It constrains the operands and the operator of the Boolean result.

A clipping result is the Boolean difference between a solid (restricted to swept area solid) and a half space solid, whereas more then one difference operation can be applied to the Boolean result.

NOTE The IfcBooleanClippingResult is defined as a special case of the boolean_result, as defined in ISO 10303-42:1994, p. 175. It has been added to apply further contraints to the CSG representation type.

HISTORY New entity in IFC Release 2.x.
ISSUE: See issues for changes made in IFC Release 2.x.

EXPRESS specification:

ENTITY IfcBooleanClippingResult
SUBTYPE OF ( IfcBooleanResult);
WHERE
WR1  :  ('IFCGEOMETRICMODELRESOURCE.IFCSWEPTAREASOLID' IN TYPEOF(FirstOperand)) OR ('IFCGEOMETRICMODELRESOURCE.IFCBOOLEANCLIPPINGRESULT' IN TYPEOF(FirstOperand));
WR2  :  ('IFCGEOMETRICMODELRESOURCE.IFCHALFSPACESOLID' IN TYPEOF(SecondOperand));
WR3  :  Operator = DIFFERENCE;
END_ENTITY;

Formal Propositions:

WR1  :  The first operand of the Boolean clipping operation shall be either an IfcSweptAreaSolid or (in case of more than one clipping) an IfcBooleanResult.
WR2  :  The second operand of the Boolean clipping operation shall be an IfcHalfSpaceSolid.
WR3  :  The Boolean operator for clipping is alway "Difference".

References (1):

Name Type Referred through Express-G
IfcBooleanResult Entity
Subtype
Diagram 1

Inheritance graph

ENTITY IfcBooleanClippingResult;
ENTITY IfcRepresentationItem;
ENTITY IfcGeometricRepresentationItem;
ENTITY IfcBooleanResult;
Operator  :  IfcBooleanOperator;
FirstOperand  :  IfcBooleanOperand;
SecondOperand  :  IfcBooleanOperand;
DERIVE
Dim  :  IfcDimensionCount :=  FirstOperand.Dim;
ENTITY IfcBooleanClippingResult;
END_ENTITY;