8.9.3.28 IfcCurveSegment
8.9.3.28.1 Semantic definition
A type of segment positioned along a curve cutting a segment from the parent curve. If the segment is placed through IfcAxis2PlacementLinear, the positioning curve (Placement.Location.BasisCurve) does not neccessarily correspond with the ParentCurve.
8.9.3.28.2 Entity inheritance
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- IfcSegment
- IfcAnnotationFillArea
- IfcBooleanResult
- IfcBoundingBox
- IfcCartesianPointList
- IfcCartesianTransformationOperator
- IfcCsgPrimitive3D
- IfcCurve
- IfcDirection
- IfcFaceBasedSurfaceModel
- IfcFillAreaStyleHatching
- IfcFillAreaStyleTiles
- IfcGeometricSet
- IfcHalfSpaceSolid
- IfcLightSource
- IfcPlacement
- IfcPlanarExtent
- IfcPoint
- IfcSectionedSpine
- IfcShellBasedSurfaceModel
- IfcSolidModel
- IfcSurface
- IfcTessellatedItem
- IfcTextLiteral
- IfcVector
8.9.3.28.3 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. |
|
| IfcSegment (2) | |||
| 1 | Transition | IfcTransitionCode |
Connectivity between the continuous segments is not enforced per se to be tangential. Setting "TangentialContinuity" to True means that the current segment shall continue with tangential continuity to the previous one. |
| UsingCurves | SET [1:?] OF IfcCompositeCurve FOR Segments |
The set of composite curves which use this composite curve segment as a segment. This set shall not be empty. |
|
| Click to show 4 hidden inherited attributes Click to hide 4 inherited attributes | |||
| IfcCurveSegment (5) | |||
| 2 | Placement | IfcPlacement |
Placement in the context of the curve using this segment. As insertion point SegmentStart is the reference point of Placement. RefDirection of Placement also specifies the sense of the trimmed segment of ParentCurve. RefDirection is bound to the paramettrization sense of the segment. |
| 3 | SegmentStart | IfcCurveMeasureSelect |
First trimming point of the curve segment on the ParentCurve. This point is used as the insertion point into the segmented, gradient or composite curve using this segment. |
| 4 | SegmentLength | IfcCurveMeasureSelect |
Length of segment measured as length or parameter value from SegmentStart. The sign of this value defines the sense agreement. |
| 5 | ParentCurve | IfcCurve |
Curve to be used as base for the segment definition. |
| * | Dim | IfcDimensionCount |
This attribute is formally derived. The space dimensionality of this class, defined by the dimensionality of the first ParentCurve. |
8.9.3.28.4 Examples
8.9.3.28.5 Formal representation
ENTITY IfcCurveSegment
SUBTYPE OF (IfcSegment);
Placement : IfcPlacement;
SegmentStart : IfcCurveMeasureSelect;
SegmentLength : IfcCurveMeasureSelect;
ParentCurve : IfcCurve;
DERIVE
Dim : IfcDimensionCount := ParentCurve.Dim;
END_ENTITY;