IfcArbitraryProfileDefWithVoids

ifcarbitraryprofiledeffithvoids定义了一个带有孔的任意闭合二维轮廓。它由外边界和内边界给出。ifcarbitraryprofiledeffithvoids的一个常见用法是用作创建扫掠曲面或扫掠实体的横截面。

IFC2x中增加的的新实体。

非正式提议：

1、外曲线和所有内曲线应为闭合曲线。

2、外曲线应包括所有内曲线。

3、内曲线不得与外曲线或任何其他内曲线相交。也就是说，考虑到几何表示上下文的几何精度因素，轮廓定义的两条曲线不得有共同点或段。换句话说，曲线不能交叉，也不能相互接触。

4、没有内曲线可以封闭另一条内曲线。

下图说明了带有空隙的任意闭合轮廓定义。在超类型IfcArbitraryClosedProfileDef中定义的外圆曲线和内曲线在相同的基础坐标系中定义。公共基础坐标系由使用轮廓定义的扫掠区域实体定义。它是xy平面：

IfcSweptAreaSolid.位置

或者，如果是截面脊椎，则为每个列表成员的xy平面IfcSectionedSpine.CrossSectionPositions（IfcSectionedSpine.CrossSectionPositions横截面位置）. OuterCurve属性定义一条二维闭合有界曲线，InnerCurves定义一组二维闭合有界曲线。

Formal Propositions

Rule	Description
WR1	The type of the profile shall be AREA, as it can only be involved in the definition of a swept area.
WR2	All inner curves shall have the dimensionality of 2.
WR3	None of the inner curves shall by of type IfcLine, as an IfcLine can not be a closed curve.

 

Attribute inheritance

#	Attribute	Type	Cardinality	Description	C
IfcProfileDef
1	ProfileType	IfcProfileTypeEnum	[1:1]	Defines the type of geometry into which this profile definition shall be resolved, either a curve or a surface area. In case of curve the profile should be referenced by a swept surface, in case of area the profile should be referenced by a swept area solid.	X
2	ProfileName	IfcLabel	[0:1]	Human-readable name of the profile, for example according to a standard profile table. As noted above, machine-readable standardized profile designations should be provided in IfcExternalReference.ItemReference.	X
	HasExternalReference	IfcExternalReferenceRelationship @RelatedResourceObjects	S[0:?]	Reference to external information, e.g. library, classification, or document information, which is associated with the profile.	X
	HasProperties	IfcProfileProperties @ProfileDefinition	S[0:?]	Additional properties of the profile, for example mechanical properties.	X
IfcArbitraryClosedProfileDef
3	OuterCurve	IfcCurve	[1:1]	Bounded curve, defining the outer boundaries of the arbitrary profile.	X
IfcArbitraryProfileDefWithVoids
4	InnerCurves	IfcCurve	S[1:?]	Set of bounded curves, defining the inner boundaries of the arbitrary profile.	X

 

Concept inheritance

 

#	Concept	Model View
IfcProfileDef
	Property Sets for Objects	Common Use Definitions

 

EXPRESS Specification

ENTITY IfcArbitraryProfileDefWithVoids
 SUBTYPE OF (IfcArbitraryClosedProfileDef);
  InnerCurves : SET [1:?] OF IfcCurve;
 WHERE
  WR1 : SELFIfcProfileDef.ProfileType = AREA;
  WR2 : SIZEOF(QUERY(temp <* InnerCurves | temp.Dim <> 2)) = 0;
  WR3 : SIZEOF(QUERY(temp <* InnerCurves | 'IFCGEOMETRYRESOURCE.IFCLINE' IN TYPEOF(temp))) = 0;
END_ENTITY;