IFC 4.3.0.1 (IFC4X3_TC1)

8.9.3.35 IfcGradientCurve

8.9.3.35.1 Semantic definition

Gradient curve is a type of curve 3D curve representation that is based on its 2D projection (BaseCurve) and a height deifned by its gradient segments which can be derived from a function that retrieves it from the segment start height, its placement and the ParentCurve instance and the type of the ParentCurve.

The parametrization of the gradient curve is based on the underlying segments of its BaseCurve. The value of the parameter equals the parameter value of BaseCurve.

8.9.3.35.2 Entity inheritance

8.9.3.35.3 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.

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.

IfcCurve (1)
* Dim IfcDimensionCount

This attribute is formally derived.

IfcCurveDim(SELF)

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

IfcCompositeCurve (4)
1 Segments LIST [1:?] OF IfcSegment

The component bounded curves, their transitions and senses. The transition attribute for the last segment defines the transition between the end of the last segment and the start of the first; this transition attribute may take the value discontinuous, which indicates an open curve.

2 SelfIntersect IfcLogical

Indication of whether the curve intersects itself or not; this is for information only.

* NSegments IfcInteger

This attribute is formally derived.

SIZEOF(Segments)

The number of component curves.

* ClosedCurve IfcLogical

This attribute is formally derived.

Segments[NSegments].Transition <> Discontinuous

Indication whether the curve is closed or not; this is derived from the transition code of the last segment.

Click to show 7 hidden inherited attributes Click to hide 7 inherited attributes
IfcGradientCurve (2)
3 BaseCurve IfcBoundedCurve

Base curve also the 2D projection of gradient curve.

4 EndPoint OPTIONAL IfcPlacement

End point of gradient curve.

Table 8.9.3.35.B

8.9.3.35.4 Examples

8.9.3.35.5 Formal representation

ENTITY IfcGradientCurve
 SUBTYPE OF (IfcCompositeCurve);
	BaseCurve : IfcBoundedCurve;
	EndPoint : OPTIONAL IfcPlacement;
END_ENTITY;

8.9.3.35.6 References

8.9.3.35.7 Changelog

8.9.3.35.7.1 IFC4.3_TC1

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