The IfcAxis1Placement provides location and direction of a single axis.
Figure 1 illustrates the definition of the IfcAxis1Placement within the parent three-dimensional coordinate system.
Figure 1 — Axis1 placement
NOTE Definition according to ISO/CD 10303-42:1992
The direction and location in three dimensional space of a single axis. An axis1_placement is defined in terms of a locating point (inherited from placement supertype) and an axis direction: this is either the direction of axis or defaults to (0.0,0.0,1.0). The actual direction for the axis placement is given by the derived attribute z.
NOTE Entity adapted from axis1_placement defined in ISO10303-42.
HISTORY New entity in IFC1.5
|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.
|1||Location||IfcPoint||The geometric position of a reference point, such as the center of a circle, of the item to be located.|
|Dim||INVALID||The space dimensionality of this class, derived from the dimensionality of the location.|
|2||Axis||OPTIONAL IfcDirection||The direction of the local Z axis.|
|Z||INVALID||The normalized direction of the local Z axis. It is either identical with the Axis value, if given, or it defaults to [0.,0.,1.]|
ENTITY IfcAxis1Placement SUBTYPE OF (IfcPlacement); Axis : OPTIONAL IfcDirection; DERIVE Z : IfcDirection := NVL (IfcNormalise(Axis), IfcRepresentationItem() || IfcGeometricRepresentationItem () || IfcDirection([0.0,0.0,1.0])); WHERE AxisIs3D : (NOT (EXISTS (Axis))) OR (Axis.Dim = 3); LocationIs3D : SELF\IfcPlacement.Location.Dim = 3; LocationIsCP : 'IFC4X3_DEV.IFCCARTESIANPOINT' IN TYPEOF(SELF\IfcPlacement.Location); END_ENTITY;