ifc边界曲面是有限面积的曲面。
注：定义根据ISO/CD 10303-42:1992
有界曲面是具有可识别边界的有限区域曲面。
注：实体改编自ISO10303-42中定义的有界曲面。
IFC2x中增加的新实体
IFC4更改实体变得抽象。
非正式提议：
①有界曲面具有有限的非零表面积。
②有界曲面有边界曲线。
| # | 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 | |||||
| IfcSurface | |||||
| Dim :=3 |
IfcDimensionCount | [1:1] | The space dimensionality of IfcSurface. It is always a three-dimensional geometric representation item. | X | |
| IfcBoundedSurface | |||||
EXPRESS Specification
ENTITY IfcBoundedSurface
ABSTRACT SUPERTYPE OF(ONEOF(IfcBSplineSurface, IfcCurveBoundedPlane, IfcCurveBoundedSurface, IfcRectangularTrimmedSurface))
SUBTYPE OF (IfcSurface);
END_ENTITY;