8.9.3.2 IfcAxis2Placement2D
8.9.3.2.1 Semantic definition
The IfcAxis2Placement2D provides location and orientation to place items in a two-dimensional space. The attribute RefDirection defines the x axis, the y axis is derived. If the attribute RefDirection is not given, the placement defaults to P[1] (x-axis) as [1.,0.] and P[2] (y-axis) as [0.,1.].
Figure 8.9.3.2.A illustrates the definition of the IfcAxis2Placement2D within the two-dimensional coordinate system.
Definition according to ISO/CD 10303-42:1992 The location and orientation in two dimensional space of two mutually perpendicular axes. An axis2_placement_2d is defined in terms of a point, (inherited from the placement supertype), and an axis. It can be used to locate and originate an object in two dimensional space and to define a placement coordinate system. The entity includes a point which forms the origin of the placement coordinate system. A direction vector is required to complete the definition of the placement coordinate system. The reference direction defines the placement X axis direction, the placement Y axis is derived from this. Entity adapted from axis2_placement_2d defined in ISO 10303-42. New entity in IFC1.5.8.9.3.2.2 Entity inheritance
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- IfcPlacement
- IfcAnnotationFillArea
- IfcBooleanResult
- IfcBoundingBox
- IfcCartesianPointList
- IfcCartesianTransformationOperator
- IfcCsgPrimitive3D
- IfcCurve
- IfcDirection
- IfcFaceBasedSurfaceModel
- IfcFillAreaStyleHatching
- IfcFillAreaStyleTiles
- IfcGeometricSet
- IfcHalfSpaceSolid
- IfcLightSource
- IfcPlanarExtent
- IfcPoint
- IfcSectionedSpine
- IfcSegment
- IfcShellBasedSurfaceModel
- IfcSolidModel
- IfcSurface
- IfcTessellatedItem
- IfcTextLiteral
- IfcVector
8.9.3.2.3 Attributes
| # | 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. The inverse attribute LayerAssignments has been added. 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. The inverse attribute StyledByItem has been added. |
|
| IfcPlacement (2) | |||
| 1 | Location | IfcPoint |
The geometric position of a reference point, such as the center of a circle, of the item to be located. |
| * | Dim | IfcDimensionCount |
This attribute is formally derived. The space dimensionality of this class, derived from the dimensionality of the location. |
| Click to show 4 hidden inherited attributes Click to hide 4 inherited attributes | |||
| IfcAxis2Placement2D (2) | |||
| 2 | RefDirection | OPTIONAL IfcDirection |
The direction used to determine the direction of the local X axis. If a value is omitted that it defaults to [1.0, 0.0.]. |
| * | P | LIST [2:2] OF IfcDirection |
This attribute is formally derived. P[1]: The normalized direction of the placement X Axis. This is [1.0,0.0] if RefDirection is omitted. P[2]: The normalized direction of the placement Y Axis. This is a derived attribute and is orthogonal to P[1]. If RefDirection is omitted, it defaults to [0.0,1.0] |
8.9.3.2.4 Formal propositions
| Name | Description |
|---|---|
| LocationIs2D |
No description available. |
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| LocationIsCP |
No description available. |
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| RefDirIs2D |
No description available. |
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8.9.3.2.5 Examples
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Figure 8.9.3.2.B -
Figure 8.9.3.2.C -
Figure 8.9.3.2.D -
Figure 8.9.3.2.E -
Figure 8.9.3.2.F -
Figure 8.9.3.2.G -
Figure 8.9.3.2.H -
Figure 8.9.3.2.I -
Figure 8.9.3.2.J -
Figure 8.9.3.2.K -
Figure 8.9.3.2.L -
Figure 8.9.3.2.M
8.9.3.2.6 Formal representation
ENTITY IfcAxis2Placement2D
SUBTYPE OF (IfcPlacement);
RefDirection : OPTIONAL IfcDirection;
DERIVE
P : LIST [2:2] OF IfcDirection := IfcBuild2Axes(RefDirection);
WHERE
LocationIs2D : SELF\IfcPlacement.Location.Dim = 2;
LocationIsCP : 'IFC4X3_DEV_bc7847cd.IFCCARTESIANPOINT' IN TYPEOF(SELF\IfcPlacement.Location);
RefDirIs2D : (NOT (EXISTS (RefDirection))) OR (RefDirection.Dim = 2);
END_ENTITY;