8.9.3.30 IfcDirection

RV ⓘ

AbV ⓘ

8.9.3.30.1 Semantic definition

The IfcDirection provides a direction in two or three dimensional space depending on the number of DirectionRatio's provided. The IfcDirection does not imply a vector length, and the direction ratios does not have to be normalized.

{ .extDef}

8.9.3.30.2 Entity inheritance

8.9.3.30.3 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. 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.
Click to show 2 hidden inherited attributes Click to hide 2 inherited attributes
IfcDirection (2)
1	DirectionRatios	LIST [2:3] OF IfcReal	The components in the direction of X axis (DirectionRatios[1]), of Y axis (DirectionRatios[2]), and of Z axis (DirectionRatios[3])
*	Dim	IfcDimensionCount	This attribute is formally derived. `HIINDEX(DirectionRatios)` The space dimensionality of this class, defined by the number of real in the list of DirectionRatios.

Table A

8.9.3.30.4 Formal propositions

Name	Description
MagnitudeGreaterZero	The magnitude of the direction vector shall be greater than zero.
`SIZEOF(QUERY(Tmp <* DirectionRatios \| Tmp <> 0.0)) > 0`

Table B

8.9.3.30.5 Formal representation

ENTITY IfcDirection
SUBTYPE OF (IfcGeometricRepresentationItem);
DirectionRatios : LIST [2:3] OF IfcReal;
DERIVE
Dim : IfcDimensionCount := HIINDEX(DirectionRatios);
WHERE
MagnitudeGreaterZero : SIZEOF(QUERY(Tmp <* DirectionRatios | Tmp <> 0.0)) > 0;
END_ENTITY;