IfcCurve是二维或三维空间中的曲线。它包括有界和无界曲线的定义。
注：根据ISO 10303-42的定义：
曲线可以想象为点在其坐标空间中移动的路径。
注：实体改编自ISO 10303-42中定义的曲线
在IFC1.0中增加的新实体
非正式提议：
■曲线应呈弧形连接
■曲线的弧长应大于零。
| # | Attribute | Type | Cardinality | Description | C |
|---|---|---|---|---|---|
| IfcRepresentationItem | |||||
| LayerAssignment | IfcPresentationLayerAssignment @AssignedItems |
S[0:1] | 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. | X | |
| StyledByItem | IfcStyledItem @Item |
S[0:1] | Reference to the IfcStyledItem that provides presentation information to the representation, e.g. a curve style, including colour and thickness to a geometric curve. | X | |
| IfcGeometricRepresentationItem | |||||
| IfcCurve | |||||
| Dim :=IfcCurveDim(SELF) |
IfcDimensionCount | [1:1] | The space dimensionality of this abstract class, defined differently for all subtypes, i.e. for IfcLine, IfcConic and IfcBoundedCurve. | X | |
EXPRESS Specification
ENTITY IfcCurve
ABSTRACT SUPERTYPE OF(ONEOF(IfcBoundedCurve, IfcConic, IfcLine, IfcOffsetCurve2D, IfcOffsetCurve3D, IfcPcurve))
SUBTYPE OF (IfcGeometricRepresentationItem);
DERIVE
Dim : IfcDimensionCount := IfcCurveDim(SELF);
END_ENTITY;