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IfcArbitraryProfileDefWithVoids

作者:互联网

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

RuleDescription
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

#AttributeTypeCardinalityDescriptionC
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

 

#ConceptModel View
IfcProfileDef
  Property Sets for Objects Common Use Definitions
 

 

 

 

EXPRESS Specification

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

 

标签:profile,定义,shall,曲线,curve,area,IfcArbitraryProfileDefWithVoids
来源: https://www.cnblogs.com/herd/p/14296154.html