|modifications||attributes DirectionRatios definition||Changed from list[2:3] of real to list[2:3] of IfcReal|
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.
NOTE Definition according to ISO/CD 10303-42:1992
This entity defines a general direction vector in two or three dimensional space. The actual magnitudes of the components have no effect upon the direction being defined, only the ratios X:Y:Z or X:Y are significant.
NOTE The components of this entity are not normalized. If a unit vector is required it should be normalized before use.
NOTE Entity adapted from direction defined in ISO 10303-42.
HISTORY New entity in IFC1.0
|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||DirectionRatios||LIST [2:3] OF IfcReal||The components in the direction of X axis (DirectionRatios), of Y axis (DirectionRatios), and of Z axis (DirectionRatios)|
|Dim||INVALID||The space dimensionality of this class, defined by the number of real in the list of DirectionRatios.|
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;