标签：multiple val sub with pre orm actual express expr
笛卡尔变换算子2d非均匀定义了二维空间中由平移、旋转、镜像和非均匀缩放组成的几何变换。非均匀缩放由两个不同的缩放因子给出：
①IfcCartesianTransformationOperator.Scale：x轴比例因子
②Scale2:y轴比例因子
如果忽略比例因子（在超级类型IfcCartesianTransformationOperator处），则默认为1.0。如果省略Scale2因子，则默认为Scale的值（x轴比例因子）。
注意，在超级类型IfcCartesianTransformationOperator中定义的比例因子（Scl）用于表示计算的比例因子（通常为x轴比例因子）。
在IFC2x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 | |||||
| IfcCartesianTransformationOperator | |||||
| 1 | Axis1 | IfcDirection | [0:1] | The direction used to determine U[1], the derived X axis direction. | X |
| 2 | Axis2 | IfcDirection | [0:1] | The direction used to determine U[2], the derived Y axis direction. | X |
| 3 | LocalOrigin | IfcCartesianPoint | [1:1] | The required translation, specified as a cartesian point. The actual translation included in the transformation is from the geometric origin to the local origin. | X |
| 4 | Scale | IfcReal | [0:1] | The scaling value specified for the transformation. | X |
| Scl :=NVL(Scale, 1.0) |
IfcReal | [1:1] | The derived scale S of the transformation, equal to scale if that exists, or 1.0 otherwise. | X | |
| Dim :=LocalOrigin.Dim |
IfcDimensionCount | [1:1] | The space dimensionality of this class, determined by the space dimensionality of the local origin. | X | |
| IfcCartesianTransformationOperator2D | |||||
| U :=IfcBaseAxis(2,SELF\IfcCartesianTransformationOperator.Axis1, SELF\IfcCartesianTransformationOperator.Axis2,?) |
IfcDirection | L[2:2] | The list of mutually orthogonal, normalized vectors defining the transformation matrix T. They are derived from the explicit attributes Axis1 and Axis2 in that order. | X | |
| IfcCartesianTransformationOperator2DnonUniform | |||||
| 5 | Scale2 | IfcReal | [0:1] | The scaling value specified for the transformation along the axis 2. This is normally the y scale factor. | X |
| Scl2 :=NVL(Scale2, SELF\IfcCartesianTransformationOperator.Scl) |
IfcReal | [1:1] | The derived scale S(2) of the transformation along the axis 2 (normally the y axis), equal to Scale2 if that exists, or equal to the derived Scl1 (normally the x axis scale factor) otherwise. | X | |
ENTITY IfcCartesianTransformationOperator2DnonUniform
SUBTYPE OF (IfcCartesianTransformationOperator2D);
Scale2 : OPTIONAL IfcReal;
DERIVE
Scl2 : IfcReal := NVL(Scale2, SELF\IfcCartesianTransformationOperator.Scl);
WHERE
Scale2GreaterZero : Scl2 > 0.0;
END_ENTITY;
IfcCartesianTransformationOperator2DnonUniform
标签：multiple val sub with pre orm actual express expr
原文地址：https://www.cnblogs.com/herd/p/13174108.html
