8.9.3.66 IfcSpiral
ABSTRACT This definition may not be instantiated
8.9.3.66.1 Semantic definition
Spirals are curves that revolve around a point while increasing its length. In general, these curves are parameterized in the following way:
x = r(ฯ) cosฯ y = r(ฯ) sinฯ
In the case of the clothoid and higher order transition spirals, the parametrization is: x = โซcos &Theta dl y = โซsin &Theta dl
where &Theta is the deflection or bearing angle and dl the differential of the spiral length.
8.9.3.66.2 Entity inheritance
-
- IfcCurve
- IfcAnnotationFillArea
- IfcBooleanResult
- IfcBoundingBox
- IfcCartesianPointList
- IfcCartesianTransformationOperator
- IfcCsgPrimitive3D
- IfcDirection
- IfcFaceBasedSurfaceModel
- IfcFillAreaStyleHatching
- IfcFillAreaStyleTiles
- IfcGeometricSet
- IfcHalfSpaceSolid
- IfcLightSource
- IfcPlacement
- IfcPlanarExtent
- IfcPoint
- IfcSectionedSpine
- IfcSegment
- IfcShellBasedSurfaceModel
- IfcSolidModel
- IfcSurface
- IfcTessellatedItem
- IfcTextLiteral
- IfcVector
8.9.3.66.3 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. |
|
| IfcCurve (1) | |||
| * | Dim | IfcDimensionCount |
This attribute is formally derived. The space dimensionality of this abstract class, defined differently for all subtypes, i.e. for IfcLine, IfcConic and IfcBoundedCurve. |
| Click to show 3 hidden inherited attributes Click to hide 3 inherited attributes | |||
| IfcSpiral (1) | |||
| 1 | Position | IfcAxis2Placement |
No description available. |
8.9.3.66.4 Formal representation
ENTITY IfcSpiral
ABSTRACT SUPERTYPE OF (ONEOF
(IfcClothoid
,IfcCosineSpiral
,IfcSecondOrderPolynomialSpiral
,IfcSeventhOrderPolynomialSpiral
,IfcSineSpiral
,IfcThirdOrderPolynomialSpiral))
SUBTYPE OF (IfcCurve);
Position : IfcAxis2Placement;
END_ENTITY;