IFC 4.3.0.1 (IFC4X3) development

8.9.3.1 IfcAxis1Placement

8.9.3.1.1 Semantic definition

The IfcAxis1Placement provides location and direction of a single axis.

axis1 placement
Figure 8.9.3.1.A — Axis1 placement

Figure 8.9.3.1.A illustrates the definition of the IfcAxis1Placement within the parent three-dimensional coordinate system.

8.9.3.1.2 Entity inheritance

8.9.3.1.3 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.

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.

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.

Location.Dim

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
IfcAxis1Placement (2)
2 Axis OPTIONAL IfcDirection

The direction of the local Z axis.

* Z IfcDirection

This attribute is formally derived.

NVL (IfcNormalise(Axis), IfcRepresentationItem() || IfcGeometricRepresentationItem () || IfcDirection([0.0,0.0,1.0]))

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.]

Table 8.9.3.1.B

8.9.3.1.4 Formal propositions

Name Description
AxisIs3D

The Axis when given should only reference a three-dimensional IfcDirection.

(NOT (EXISTS (Axis))) OR (Axis.Dim = 3)
LocationIs3D

The Cartesian point defining the Location shall have the dimensionality of 3.

SELF\IfcPlacement.Location.Dim = 3
LocationIsCP

No description available.

'IFC4X3_DEV_cedaad7e.IFCCARTESIANPOINT' IN TYPEOF(SELF\IfcPlacement.Location)
Table 8.9.3.1.C

8.9.3.1.5 Formal representation

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_cedaad7e.IFCCARTESIANPOINT' IN TYPEOF(SELF\IfcPlacement.Location);
END_ENTITY;

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8.9.3.1.6 Changelog

  • where rule, AxisIs3D
  • where rule, LocationIs3D
  • where rule, WR1
  • where rule, WR2
  • where rule, LocationIsCP