标签：换算 ecif img tran scale The val ant ems
IfcCartesianTransformationOperator2D定义二维空间中的几何变换。
注释定义符合ISO/CD 10303-42:1992
笛卡尔变换算子2d定义了二维空间中由平移、旋转、镜像和均匀缩放组成的几何变换。规范化向量u的列表定义正交矩阵T的列。这些向量由基轴函数从方向属性axis1和axis2计算。如果| T |=-1，则转换包括镜像。
注：实体改编自ISO10303-42中定义的笛卡尔变换算子。
在IFC2x中增加的新实体。
Formal Propositions
| Rule | Description |
|---|---|
| DimEqual2 | The coordinate space dimensionality of this entity shall be 2. |
| Axis1Is2D | The inherited Axis1 should have (if given) the dimensionality of 2. |
| Axis2Is2D | The inherited Axis2 should have (if given) the dimensionality of 2. |
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 | |||||
| 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 | |
ENTITY IfcCartesianTransformationOperator2D
SUPERTYPE OF(IfcCartesianTransformationOperator2DnonUniform)
SUBTYPE OF (IfcCartesianTransformationOperator);
DERIVE
U : LIST [2:2] OF IfcDirection := IfcBaseAxis(2,SELF\IfcCartesianTransformationOperator.Axis1, SELF\IfcCartesianTransformationOperator.Axis2,?);
WHERE
DimEqual2 : SELF\IfcCartesianTransformationOperator.Dim = 2;
Axis1Is2D : NOT(EXISTS(SELF\IfcCartesianTransformationOperator.Axis1)) OR (SELF\IfcCartesianTransformationOperator.Axis1.Dim = 2);
Axis2Is2D : NOT(EXISTS(SELF\IfcCartesianTransformationOperator.Axis2)) OR (SELF\IfcCartesianTransformationOperator.Axis2.Dim = 2);
END_ENTITY;
IfcCartesianTransformationOperator2D
标签：换算 ecif img tran scale The val ant ems
原文地址：https://www.cnblogs.com/herd/p/13174164.html
