ifc4x3 IfcAdvancedBrepWithVoids

IfcAdvancedBrepWithVoids

1语义定义

IfcAdvancedBrepWithVoids是高级B-rep的一种专门化，其内部包含一个或多个空隙。空隙表示为闭合壳，其定义使得壳法线指向空隙。

 

注：根据ISO 10303-42中定义的advanced_brep_shape_presentation改编的实体。

IFC4中的新实体

 

非正式提议：

1. 每个空壳应与外壳和其他空壳分离
2. 每个空壳应封闭在外壳内，但不得封闭在任何其他空壳内。特别是外壳不在空心壳组中
3. IfcManifoldSolidBrep中的每个外壳只能引用一次。
4. IfcAdvancedBrep和IfcAdvanceBrepWithVoids中所有壳体的所有表面。Voids应为IfcAdvanedFace类型。

 

 

2实体继承

 

 

3实体属性

#	Attribute	Type	Description
IfcRepresentationItem (2)
	LayerAssignment	SET [0:1] OF IfcPresentationLayerAssignment FOR AssignedItems	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. IFC2X3-CHANGE The inverse attribute LayerAssignments has been added.IFC4-CHANGE The inverse attribute LayerAssignment has been restricted to max 1. Upward compatibility for file based exchange is guaranteed.
	StyledByItem	SET [0:1] OF IfcStyledItem FOR Item	Reference to the IfcStyledItem that provides presentation information to the representation, e.g. a curve style, including colour and thickness to a geometric curve. IFC2X3-CHANGE The inverse attribute StyledByItem has been added.
IfcSolidModel (1)
*	Dim	IfcDimensionCount	This attribute is formally derived. 3 The space dimensionality of this class, it is always 3.
IfcManifoldSolidBrep (1)
1	Outer	IfcClosedShell	A closed shell defining the exterior boundary of the solid. The shell normal shall point away from the interior of the solid.
Click to show 4 hidden inherited attributes Click to hide 4 inherited attributes
IfcAdvancedBrepWithVoids (1)
2	Voids	SET [1:?] OF IfcClosedShell	No description available.

 

 

 

ENTITY IfcAdvancedBrepWithVoids
 SUBTYPE OF (IfcAdvancedBrep);
    Voids : SET [1:?] OF IfcClosedShell;
 WHERE
    VoidsHaveAdvancedFaces : SIZEOF (QUERY (Vsh <* Voids |
  SIZEOF (QUERY (Afs <* Vsh.CfsFaces |
  (NOT ('IFC4X3.IFCADVANCEDFACE' IN TYPEOF(Afs)))
  )) = 0
)) = 0;
END_ENTITY;

 

 

 

 

 

 

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