IfcCurve

Definition from ISO/CD 10303-42:1992: A curve can be envisioned as the path of a point moving in its coordinate space.

NOTE: Corresponding STEP entity: curve, only the following subtypes have been incorporated into IFC: line as IfcLine, conic as IfcConic, bounded_curve as IfcBoundedCurve. Please refer to ISO/IS 10303-42:1994, p.37 for the final definition of the formal standard. The derived attribute Dim has been added (see also note at IfcGeometricRepresentationItem).

HISTORY: New entity in IFC Release 1.0

Informal proposition:

A curve shall be arcwise connected
A curve shall have an arc length greater than zero.

EXPRESS specification:

ENTITY IfcCurve

ABSTRACT SUPERTYPE OF

(ONEOF(IfcBoundedCurve, IfcConic, IfcLine, IfcOffsetCurve2D, IfcOffsetCurve3D))

SUBTYPE OF (

IfcGeometricRepresentationItem);

DERIVE

Dim

IfcDimensionCount := IfcCurveDim(SELF);

END_ENTITY;

Attribute definitions:

Dim

The space dimensionality of this abstract class, defined differently for all subtypes, i.e. for IfcLine, IfcConic and IfcBoundedCurve.

Inheritance graph

ENTITY IfcCurve;

ENTITY IfcRepresentationItem;

INVERSE

LayerAssignments

SET OF IfcPresentationLayerAssignment FOR AssignedItems;

StyledByItem

SET [0:1] OF IfcStyledItem FOR Item;

ENTITY IfcGeometricRepresentationItem;

ENTITY IfcCurve;

DERIVE

Dim

IfcDimensionCount := IfcCurveDim(SELF);

END_ENTITY;