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IfcDimensionCurve

Definition from IAI: A dimension curve is an annotated curve within a dimension that has the dimension text and may have terminator symbols assigned. It is used to present the extent and the direction of the dimension.

NOTE: The dimension text is not directly associated to the IfcDimensionCurve. It is associated as IfcStructuredDimensionCallout via the IfcDimensionCalloutRelationship to the dimension (one of IfcAngularDimension, IfcDiameterDimension, IfcLinearDimension, or IfcRadiusDimension).

Dimension Curve  

NOTE: The IfcDimensionCurve is an entity that had been adopted from ISO 10303, Industrial automation systems and integration—Product data representation and exchange, Part 101: Integrated application resources: Draughting.

NOTE Corresponding STEP name: dimension_curve. Please refer to ISO/IS 10303-101:1994 page 15 for the final definition of the formal standard.

HISTORY New entity in Release IFC2x 2nd Edition.

EXPRESS specification:

ENTITY IfcDimensionCurve
SUBTYPE OF ( IfcAnnotationCurveOccurrence);
INVERSE
AnnotatedBySymbols  :  SET [0:2] OF IfcTerminatorSymbol FOR AnnotatedCurve;
WHERE
WR51  :  SIZEOF(USEDIN(SELF,'IFCPRESENTATIONDIMENSIONINGRESOURCE.IFCDRAUGHTINGCALLOUT.CONTENTS')) >= 1;
WR52  :  (SIZEOF(QUERY (Dct1 <* USEDIN(SELF,'IFCPRESENTATIONDIMENSIONINGRESOURCE.' + 'IFCTERMINATORSYMBOL.ANNOTATEDCURVE') | (Dct1.Role = IfcDimensionExtentUsage.ORIGIN))) <= 1) AND (SIZEOF(QUERY (Dct2 <* USEDIN(SELF,'IFCPRESENTATIONDIMENSIONINGRESOURCE.' + 'IFCTERMINATORSYMBOL.ANNOTATEDCURVE') | (Dct2.Role = IfcDimensionExtentUsage.TARGET))) <= 1);
WR53  :  SIZEOF(QUERY (Dct <* AnnotatedBySymbols | NOT('IFCPRESENTATIONDIMENSIONINGRESOURCE.IFCDIMENSIONCURVETERMINATOR' IN TYPEOF(Dct)))) = 0 ;
END_ENTITY;

Attribute definitions:

AnnotatedBySymbols  :  Reference to the terminator symbols that may be assigned to the dimension curve. There shall be either zero, one or two terminator symbols assigned.

Formal Propositions:

WR51  :  A dimension curve shall be used by at least one referencing dimension curve directed callout, i.e. it should not be used outside of the context of a dimension element group.
WR52  :  The dimension curve should not be annotated with more than one terminator having the role "Origin", nor with more than one terminator having the role "Target".
WR53  :  All terminators assigned to a dimension curve shall be dimension curve terminators.

Inheritance graph

ENTITY IfcDimensionCurve;
ENTITY IfcRepresentationItem;
INVERSE
LayerAssignments  :  SET OF IfcPresentationLayerAssignment FOR AssignedItems;
StyledByItem  :  SET [0:1] OF IfcStyledItem FOR Item;
ENTITY IfcStyledItem;
Item  :  OPTIONAL IfcRepresentationItem;
Styles  :  SET [1:?] OF IfcPresentationStyleAssignment;
Name  :  OPTIONAL IfcLabel;
ENTITY IfcAnnotationOccurrence;
ENTITY IfcAnnotationCurveOccurrence;
ENTITY IfcDimensionCurve;
INVERSE
AnnotatedBySymbols  :  SET [0:2] OF IfcTerminatorSymbol FOR AnnotatedCurve;
END_ENTITY;