IfcGeometricConstraintResource(几何模型资源)
模式IfcGeometricModelResource定义用于几何模型表示的资源。此资源的主要应用是表示产品模型的形状或几何形式。以下是几何模型资源当前版本中几何模型表示的范围:
①描述三维实体精确几何形态的数据;
②构造性立体几何模型;
③半空间的定义;
④通过扫描操作创建实体模型;
⑤流形边界表示(brep)模型;
⑥表面模型;
⑦镶嵌模型;
⑧几何集合。
8.8 IfcGeometricModelResource
Types
1 IfcBooleanOperator (布尔运算符类型)
2 IfcBooleanOperand (布尔运算类型)
3 IfcCsgSelect (构造几何实体选择类型)
4 IfcGeometricSetSelect (几何集选择)
Entities
1 IfcAdvancedBrep (高级边界实体)
2 IfcAdvancedBrepWithVoids (有镂空的高级边界实体)
3 IfcBlock (块实体)
4 IfcBooleanClippingResult (布尔裁剪结果实体类)
5 IfcBooleanResult (布尔结果实体)
6 IfcBoundingBox (边界框实体)
7 IfcBoxedHalfSpace (半空间实体)
8 IfcCartesianPointList (笛卡尔数据列表实体)
9 IfcCartesianPointList2D (二维笛卡尔数据列表)
10 IfcCartesianPointList3D (三维笛卡尔数据列表)
11 IfcCsgPrimitive3D (基本三维构造几何实实体)
12 IfcCsgSolid (构造几何实体)
13 IfcExtrudedAreaSolid ()
14 IfcExtrudedAreaSolidTapered ()
15 IfcFaceBasedSurfaceModel (基于面的曲面模型实体)
16 IfcFacetedBrep (面边界)
17 IfcFacetedBrepWithVoids (有空隙的面边界)
18 IfcFixedReferenceSweptAreaSolid ()
19 IfcGeometricCurveSet ()
20 IfcGeometricSet (几何集合)
21 IfcHalfSpaceSolid (半空间实体)
22 IfcManifoldSolidBrep (流形固体曲面)
23 IfcPolygonalBoundedHalfSpace (多边形有界半空间)
24 IfcRectangularPyramid (矩形锥形)
25 IfcRevolvedAreaSolid ()
26 IfcRevolvedAreaSolidTapered ()
27 IfcRightCircularCone ()
28 IfcRightCircularCylinder ()
29 IfcSectionedSpine ()
30 IfcShellBasedSurfaceModel (壳体表面模型)
31 IfcSolidModel (实体模型)
32 IfcSphere (球体)
33 IfcSurfaceCurveSweptAreaSolid ()
34 IfcSweptAreaSolid ()
35 IfcSweptDiskSolid ()
36 IfcSweptDiskSolidPolygonal (实心多边形)
37 IfcTessellatedFaceSet ()
38 IfcTessellatedItem (镶嵌项)
39 IfcTriangulatedFaceSet (三角面集合)
Functions
1 IfcTaperedSweptAreaProfiles (锥型剖面)
2 IfcPointListDim (点列表维度)
类型:
1 IfcBooleanOperator (布尔运算符类型)
应用于第一个和第二个布尔操作数的布尔运算符。
Enumeration definition
Constant | Description |
---|---|
UNION | The operation of constructing the regularized set theoretic union of the volumes defined by two solids. |
INTERSECTION | The operation of constructing the regularised set theoretic intersection of the volumes defined by two solids. |
DIFFERENCE | The regularised set theoretic difference between the volumes defined by two solids. |
2 IfcBooleanOperand (布尔运算类型)
选择类型,包括可能参与布尔运算以形成CSG实体的所有几何表示项。它包括实体模型、半空间实体和CSG基元。布尔结果也可以用作操作数,从而启用嵌套布尔操作。
Enumeration definition
Constant | Description |
---|---|
IfcSolidModel | |
IfcHalfSpaceSolid | |
IfcBooleanResult | |
IfcCsgPrimitive3D |
3 IfcCsgSelect (构造几何实体选择类型)
选择类型,方便在IfcCsgSolid中选择IfcBooleanResult和IfcCsgPrimitive3D的子类型作为潜在的根树表达式。
4 IfcGeometricSetSelect (几何集选择)
实体:
1 IfcAdvancedBrep (高级边界实体)
2 IfcAdvancedBrepWithVoids (有镂空的高级边界实体)
3 IfcBlock (块实体)
IfcBlock是一个构造实体几何(CSG)三维基本体。它由三个正交轴上的位置和正定距离来定义。继承的位置属性具有IFCAXISPLATEX3D类型,并提供:
●自动机3DD位置:原语轴系统的位置和方位。
●SELFIfcCsgPrimitive3D.Position.Location:块在位置上有一个顶点,并且边在正方向上与放置轴对齐。
XLength、YLength和ZLength属性定义IfcBlock沿三个轴的大小。
在每个侧面上,纹理都是垂直对齐的。在顶面和底面上,纹理前后对齐。纹理根据重复和重复被拉伸或重复到每个面的程度。
图308说明了具有钳制纹理的默认纹理映射(RepeatS=False和RepeatT=False)。左边的图像显示S轴指向右边的纹理,T轴指向上的纹理。右边的图像显示了纹理的几何形状,其中X轴指向右边,Y轴指向左边,Z轴指向上。
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Figure 308 — Block textures |
Attribute definitions
# | Attribute | Type | Cardinality | Description | C |
---|---|---|---|---|---|
2 | XLength | IfcPositiveLengthMeasure | [1:1] | The size of the block along the placement X axis. It is provided by the inherited axis placement through SELFIfcCsgPrimitive3D.Position.P[1]. | X |
3 | YLength | IfcPositiveLengthMeasure | [1:1] | The size of the block along the placement Y axis. It is provided by the inherited axis placement through SELFIfcCsgPrimitive3D.Position.P[2]. | X |
4 | ZLength | IfcPositiveLengthMeasure | [1:1] | The size of the block along the placement Z axis. It is provided by the inherited axis placement through SELFIfcCsgPrimitive3D.Position.P[3]. | X |
Inherited definitions from supertypes
Entity inheritanceAttribute inheritance
# | 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 | |||||
IfcCsgPrimitive3D | |||||
1 | Position | IfcAxis2Placement3D | [1:1] | The placement coordinate system to which the parameters of each individual CSG primitive apply. | X |
Dim :=3 |
IfcDimensionCount | [1:1] | The space dimensionality of this geometric representation item, it is always 3. | X | |
IfcBlock | |||||
2 | XLength | IfcPositiveLengthMeasure | [1:1] | The size of the block along the placement X axis. It is provided by the inherited axis placement through SELFIfcCsgPrimitive3D.Position.P[1]. | X |
3 | YLength | IfcPositiveLengthMeasure | [1:1] | The size of the block along the placement Y axis. It is provided by the inherited axis placement through SELFIfcCsgPrimitive3D.Position.P[2]. | X |
4 | ZLength | IfcPositiveLengthMeasure | [1:1] | The size of the block along the placement Z axis. It is provided by the inherited axis placement through SELFIfcCsgPrimitive3D.Position.P[3]. | X |
4 IfcBooleanClippingResult (布尔裁剪结果实体类)
5 IfcBooleanResult (布尔结果实体)
6 IfcBoundingBox (边界框实体)
IfcBoundingBox定义了一个与定义它的对象坐标系的轴平行的正交长方体。它是由一个角点定义的,角点是三维笛卡尔点,三个长度度量值定义盒子在正轴方向上的X、Y和Z参数。
Attribute definitions
# | Attribute | Type | Cardinality | Description | C |
---|---|---|---|---|---|
1 | Corner | IfcCartesianPoint | [1:1] | Location of the bottom left corner (having the minimum values). | X |
2 | XDim | IfcPositiveLengthMeasure | [1:1] | Length attribute (measured along the edge parallel to the X Axis) | X |
3 | YDim | IfcPositiveLengthMeasure | [1:1] | Width attribute (measured along the edge parallel to the Y Axis) | X |
4 | ZDim | IfcPositiveLengthMeasure | [1:1] | Height attribute (measured along the edge parallel to the Z Axis). | X |
Dim :=3 |
IfcDimensionCount | [1:1] | The space dimensionality of this class, it is always 3. | X |
Attribute inheritance
7 IfcBoxedHalfSpace (半空间实体)
IfcBoxedHalfSpace仅在布尔操作中使用(作为其超类型IfcHalfSpaceSolid)。它将域精确地划分为两个子集,其中所讨论的域是属性封闭的域。
属性封闭的目的是为布尔操作中的其他操作数提供一个搜索框。它应足够大,以便在布尔运算后用半空间完全封闭生成的实体。但是,它不会改变最终结果。布尔操作的结果将是相同的,就像由超类型IfcHalfSpaceSolid执行一样。参见下面的图:
提供外壳的IfcBoundingBox是为了方便接收应用程序,以便使用大小框比较来提高效率(例如,首先检查大小框是否相交,如果不相交,则不必进行计算来检查实体是否相交)。
因此,外壳有助于防止处理与无限大小相关的问题。封闭框位于对象坐标系内,由所表示元素的ObjectPlacement(例如,IfcLocalPlacement)建立。图311显示了封闭框足够大,可以完全封闭布尔结果。
Entity inheritance
Attribute inheritance
# | 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 | |||||
IfcHalfSpaceSolid | |||||
1 | BaseSurface | IfcSurface | [1:1] | Surface defining side of half space. | X |
2 | AgreementFlag | IfcBoolean | [1:1] | The agreement flag is TRUE if the normal to the BaseSurface points away from the material of the IfcHalfSpaceSolid. Otherwise it is FALSE. | X |
Dim :=3 |
IfcDimensionCount | [1:1] | The space dimensionality of this class, it is always 3 | X | |
IfcBoxedHalfSpace | |||||
3 | Enclosure | IfcBoundingBox | [1:1] | The box which bounds the resulting solid of the Boolean operation involving the half space solid for computational purposes only. | X |
8 IfcCartesianPointList (笛卡尔数据列表实体)
IfcCartesianPointList是点列表的抽象超类型。
Attribute definitions
# | Attribute | Type | Cardinality | Description | C |
---|---|---|---|---|---|
Dim :=IfcPointListDim(SELF) |
IfcDimensionCount | [1:1] | The space dimensionality of this class, either 2 or 3, depending on the sub type. | X |
Inherited definitions from supertypes
Entity inheritance
Attribute inheritance
# | 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 | |||||
IfcCartesianPointList | |||||
Dim :=IfcPointListDim(SELF) |
IfcDimensionCount | [1:1] | The space dimensionality of this class, either 2 or 3, depending on the sub type. | X |
9 IfcCartesianPointList2D (二维笛卡尔数据列表)
IfcCartesianPointList2D定义二维笛卡尔点的有序集合。每个笛卡尔点由两个坐标的固定列表提供为二维点。属性CoordList是一个二维列表,其中
●第一维度是表示每个二维笛卡尔点的无界列表;
●第二维度是两个列表成员的固定列表,其中[1]是笛卡尔点的x坐标,[2]是笛卡尔点的y坐标。
Attribute definitions
# | Attribute | Type | Cardinality | Description | C |
---|---|---|---|---|---|
1 | CoordList | IfcLengthMeasure | L[1:?]L[2:2] | Two-dimensional list of Cartesian points provided by two coordinates. | X |
Inherited definitions from supertypes
Entity inheritance
Attribute inheritance
# | 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 | |||||
IfcCartesianPointList | |||||
Dim :=IfcPointListDim(SELF) |
IfcDimensionCount | [1:1] | The space dimensionality of this class, either 2 or 3, depending on the sub type. | X | |
IfcCartesianPointList2D | |||||
1 | CoordList | IfcLengthMeasure | L[1:?]L[2:2] | Two-dimensional list of Cartesian points provided by two coordinates. | X |
10 IfcCartesianPointList3D (三维笛卡尔数据列表)
IfcCartesianPointList3D定义三维笛卡尔点的有序集合。每个笛卡尔点由一个固定的三坐标列表提供为三维点。属性CoordList是一个二维列表,其中
●第一维度是表示每个三维笛卡尔点的无边界列表;
●第二维度是由三个列表成员组成的固定列表,其中[1]是笛卡尔点的x坐标,[2]是y坐标,[3]是z坐标。
Attribute definitions
# | Attribute | Type | Cardinality | Description | C |
---|---|---|---|---|---|
1 | CoordList | IfcLengthMeasure | L[1:?]L[3:3] | Two-dimensional list of Cartesian points provided by three coordinates. | X |
Inherited definitions from supertypes
Entity inheritance
Attribute inheritance
# | 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 | |||||
IfcCartesianPointList | |||||
Dim :=IfcPointListDim(SELF) |
IfcDimensionCount | [1:1] | The space dimensionality of this class, either 2 or 3, depending on the sub type. | X | |
IfcCartesianPointList3D | |||||
1 | CoordList | IfcLengthMeasure | L[1:?]L[3:3] | Two-dimensional list of Cartesian points provided by three coordinates. | X |
11 IfcCsgPrimitive3D (基本三维构造几何实体实体)
IfcCsgPrimitive3D是所有三维原语的抽象超类型,用作树根项或CSG实体模型中的布尔结果。所有三维CSG基元都是在三维放置坐标系中定义的。
Attribute definitions
# | Attribute | Type | Cardinality | Description | C |
---|---|---|---|---|---|
1 | Position | IfcAxis2Placement3D | [1:1] | The placement coordinate system to which the parameters of each individual CSG primitive apply. | X |
Dim :=3 |
IfcDimensionCount | [1:1] | The space dimensionality of this geometric representation item, it is always 3. | X |
Inherited definitions from supertypes
Entity inheritance
Attribute inheritance
# | 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 | |||||
IfcCsgPrimitive3D | |||||
1 | Position | IfcAxis2Placement3D | [1:1] | The placement coordinate system to which the parameters of each individual CSG primitive apply. | X |
Dim :=3 |
IfcDimensionCount | [1:1] | The space dimensionality of this geometric representation item, it is always 3. | X |
12 IfcCsgSolid (构造几何实体)
ifccsg实体是使用构造性实体几何模型表示三维形状的实体。它由单个3D CSG基元表示,或作为布尔运算的结果。布尔运算的操作数可以是布尔运算本身,形成CSG树。以下卷可以是CSG树的一部分:实体模型,例如面B-Rep(IfcFacetedBrep,IfcFacetedBrepWithVoids)、扫描区域实体(IfcExtrudedAreaSolid,ifcRevolveAreaSolid,IfcSurfaceCurveSweptAreaSolid)、扫描磁盘实体(IfcSweptDiskSolid)、半空间实体(IfcHalfSpaceSolid和子类型)和CSG原语(子类型IfcCsgPrimitive3D)。
CSG实体的完整定义需要两种信息:几何和结构。
几何信息通过实体模型传递。这些通常是基本体,例如圆柱体、楔体和拉伸体,但可以包括常规的B-Rep模型。实体模型也可以是半空间实体。
结构信息位于布尔结果和构造几何实体的树(严格来说是无环有向图)中,它们表示构建实体的“配方”。终端节点是几何基本体和其他实体。每个CSG实体都有一个与之相关联的布尔结果,它是定义实体的树的根。(树中可能还有更多布尔结果作为操作数)。CSG实体的意义在于,由关联树定义的实体被标识为一个重要对象本身,并且通过这种方式,它与表示构建过程中中间结果的其他布尔结果实体不同。
块几何可以用构造性实体几何模型来表示,表示为CSG基元。
13 IfcExtrudedAreaSolid ()
IfcExtrudedAreaSolid是通过扫描轮廓定义提供的横截面来定义的。挤出方向由“挤出方向”属性指定,挤出长度由“深度”属性指定。如果平面区域有内边界(定义的孔),则应将这些孔扫入实体的孔中。
生成的实体由IfcSweptAreaSolid.Position相对于对象坐标系定位。如果提供,则允许重新定位拉伸实体。如果未提供,则默认为当前对象坐标系。挤出方向在由IfcSweptAreaSolid.position定义的位置坐标系内给定。挤压方向可以是不垂直于位置坐标系的Z轴的任何方向。
对于侧面,纹理是朝着垂直方向连续对齐的,沿着侧面,原点位于任意轮廓的第一个点,并沿着轮廓的外部边界逆时针(如上图所示)。对于参数化外形,原点定义为圆形外形的+Y范围(没有锐边)和所有其他外形的+Y范围的第一个逆时针锐边。纹理根据重复在轮廓的外边界的每一侧拉伸或重复。纹理沿拉伸轴沿拉伸轴的两侧延伸或重复。
对于顶部和底部封口,纹理是前后对齐的,原点在最小的X和Y范围内。纹理根据重复和重复在每个面的顶部和底部拉伸或重复。
对于具有空隙的截面轮廓,纹理将沿内侧垂直对齐,原点位于任意截面轮廓的第一个点,并顺时针遵循截面轮廓的内边界(如上图所示)。对于参数化外形,内侧的原点定义在圆形外形的+Y范围内(没有锐边,如空心椭圆或圆角矩形),对于所有其他外形,第一锐边从+Y范围顺时针定义。
示例图说明了具有重复纹理(RepeatS=True和RepeatT=True)的默认纹理映射。左边的图像显示S轴指向右边的纹理,T轴指向上的纹理。右边的图像显示了纹理的几何形状,其中X轴指向右边,Y轴指向左边,Z轴指向上。对于具有IccHiPiPrPieleDF的轮廓的IFCExpDeDeaRealSoLID,侧纹理坐标原点是从+y轴顺时针方向的第一个角计数器,它等于(-0.5*IfcIShapeProfileDef.OverallWidth, +0.5*IfcIShapeProfileDef.OverallDepth),
而顶部(端盖)纹理坐标从(-0.5*IfcIShapeProfileDef.OverallWidth, -0.5*IfcIShapeProfileDef.OverallDepth).
此示例说明了具有拉伸实体几何图形的标准事例列,该列基于参数化的I形截面轮廓和相应的材质截面轮廓集使用定义。图441显示了结果形状。
14 IfcExtrudedAreaSolidTapered ()
15 IfcFaceBasedSurfaceModel (基于面的曲面模型实体)
16 IfcFacetedBrep (面边界)
17 IfcFacetedBrepWithVoids (有空隙的面边界)
18 IfcFixedReferenceSweptAreaSolid ()
19 IfcGeometricCurveSet ()
20 IfcGeometricSet (几何集合)
21 IfcHalfSpaceSolid (半空间实体)
22 IfcManifoldSolidBrep (流形固体曲面)
23 IfcPolygonalBoundedHalfSpace (多边形有界半空间)
多边形有界半空间是半空间实体的一种特殊子类型,其中布尔表达式中使用的半空间的材质由多边形边界限定。半空间的底面由其相对于对象坐标系的法向定位(在超类型IfcHalfSpaceSolid中定义),其多边形(带或不带弧段)边界在由位置属性建立的位置坐标系的XY平面中定义,减法体垂直于位置坐标系的XY平面挤压,即,由位置属性定义的正Z轴的方向。
边界由位置坐标系XY平面内的二维多段线(或由直线段和圆弧段组成的二维复合曲线)定义。曲面在半空间中的边由曲面法线和协定标志确定。如果agreement标志为TRUE,则该子集是正常点远离的子集。如果agreement标志为FALSE,那么该子集就是normal指向的子集。
●黑色坐标表示对象坐标系(通常由IfcLocalPlacement提供)。
●绿色坐标表示位置坐标系;多边形边界在此坐标系内给出。它由IfcPolygonalBoundedHalfSpace.Position提供。此坐标系相对于对象坐标系。减法体的挤压方向是正Z轴。
●红色坐标表示平面的法向。它由基面(IfcSurface.Position)提供。此法线也与对象坐标系相关。
24 IfcRectangularPyramid (矩形锥形)
IfcRectangularPyramid是一个构造实体几何(CSG)三维基本体。它是一个有一个矩形底部和一个叫做顶点的点作为顶部的实体。从底部到顶部逐渐变细。从基部到顶点的轴线垂直于基部。继承的位置属性定义了IFCAXISPLATES3D,并提供了金字塔的位置和方向:
●自动机3DD位置:原语轴系统的位置和方位。
●SELFIfcCsgPrimitive3D.Position.Location:圆形区域的中心是圆锥体的底面。
●自IFCsgPrimiTig.3D位置。[3 ]:遗传布局坐标系的Z轴提供了IfcRealDealARTION的中心轴,顶点位于Z轴的正方向上的高度值。底半径定义放置坐标系xy平面上的圆形底面。
如图,金字塔位于其自身的放置坐标系内。原点是位于XY平面的底部矩形的中心。顶点位于正Z轴处[ 0, 0,高度]。
在每个三角形侧面上,纹理都是垂直对齐的。纹理根据重复被拉伸或重复到每个面的底部。根据Repeat T向顶点拉伸或重复纹理,如果Repeat为False,则顶点的坐标为(0.5,1.0)。
在底面上,纹理前后对齐。
图319说明了使用钳制纹理的默认纹理映射(RepeatS=False和RepeatT=False)。左边的图像显示S轴指向右边的纹理,T轴指向上的纹理。右边的图像显示了纹理的几何形状,其中X轴指向右边,Y轴指向左边,Z轴指向上。
25 IfcRevolvedAreaSolid ()
26 IfcRevolvedAreaSolidTapered ()
27 IfcRightCircularCone ()
28 IfcRightCircularCylinder ()
29 IfcSectionedSpine ()
30 IfcShellBasedSurfaceModel (壳体表面模型)
IfcShellBasedSurfaceModel通过一组打开或关闭的壳来表示形状。壳内的连接面具有维度2,并且放置在维度3的坐标空间中。
基于壳的曲面模型由一组开壳或闭壳描述。除边缘和顶点外,外壳不得相交。特别是,不同的面可能不相交。一个壳的完整面可以与另一个壳共享。壳的重合部分应参考定义重合区域的相同面、边和顶点。至少应有一个外壳。壳可以独立于表面模型而存在。
31 IfcSolidModel (实体模型)
32 IfcSphere (球体)
IfcSphere是一个构造实体几何(CSG)三维基本体。它是一个实体,曲面上的所有点与中心点的距离都相同。继承的位置属性定义了IFCAXISPLATEX3D并提供:
①位置:原语轴系统的位置和方位。
②SELFIfcCsgPrimitive3D.Position.Location:球体的中心。
③z坐标轴(3):Z轴指向其正极朝向北极,其负向指向南极。
如图:球体的几何参数。球体位于相对于对象坐标系的其自身放置坐标系内。原点是球体的中心。
33 IfcSurfaceCurveSweptAreaSolid ()
34 IfcSweptAreaSolid ()
35 IfcSweptDiskSolid ()
36 IfcSweptDiskSolidPolygonal (实心多边形)
37 IfcTessellatedFaceSet ()
38 IfcTessellatedItem (镶嵌项)
39 IfcTriangulatedFaceSet (三角面集合)
函数:
1 IfcTaperedSweptAreaProfiles (锥型剖面)
2 IfcPointListDim (点列表维度)