IfcConic

IfcConic是参数化的平面曲线。

注：定义根据ISO/CD 10303-42:1992

圆锥曲线是一个平面曲线，它可以由一个平面与一个圆锥相交而成。圆锥曲线是根据其固有的几何性质来定义的，而不是用其他几何来描述的。圆锥实体始终有一个由axis2_placement定义的放置坐标系；参数表示是根据该放置坐标系定义的。

注：实体改编自ISO 10303-42中定义的圆锥曲线

IFC1.0中增加的新实体

#	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
IfcConic
1	Position	IfcAxis2Placement	[1:1]	The location and orientation of the conic. Further details of the interpretation of this attribute are given for the individual subtypes."	X

 

EXPRESS Specification

ENTITY IfcConic
 ABSTRACT SUPERTYPE OF(ONEOF(IfcCircle, IfcEllipse))
 SUBTYPE OF (IfcCurve);
  Position : IfcAxis2Placement;
END_ENTITY;