8.9.3.63 IfcSeventhOrderPolynomialSpiral
8.9.3.63.1 Semantic definition
The IfcSeventhOrderPolynomialSpiral is a specialization of IfcSpiral. The curvature Îș and radius of the curvature Ï, at any point of the curve, are related to the arc length s by the seventh order formulae:
Figure 8.9.3.63.A Interpretation of the parameters:
C = SELF\IfcSpiral.Position.Location x = SELF\IfcSpiral.Position.P[1] y = SELF\IfcSpiral.Position.P[2] A7 = SepticTerm A6 = SexticTerm A5 = QuinticTerm A4 = QuarticTerm A3 = CubicTerm A2 = QuadraticTerm A1 = LinearTerm A0 = ContantTerm
and the seventh order polynomial spiral is parameterized as:
Figure 8.9.3.63.B where:
Figure 8.9.3.63.C and the parametric range is: -â < u < â.
8.9.3.63.2 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
8.9.3.63.3 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. |
| IfcSpiral (1) | |||
| 1 | Position | IfcAxis2Placement |
No description available. |
| Click to show 4 hidden inherited attributes Click to hide 4 inherited attributes | |||
| IfcSeventhOrderPolynomialSpiral (8) | |||
| 2 | SepticTerm | IfcLengthMeasure |
The constant that defines the septic term in the equation which defines the relation between curvature and arc length for the curve. |
| 3 | SexticTerm | OPTIONAL IfcLengthMeasure |
The constant that defines the sextic term in the equation which defines the relation between curvature and arc length for the curve. |
| 4 | QuinticTerm | OPTIONAL IfcLengthMeasure |
The constant that defines the quintic term in the equation which defines the relation between curvature and arc length for the curve. |
| 5 | QuarticTerm | OPTIONAL IfcLengthMeasure |
The constant that defines the quartic term in the equation which defines the relation between curvature and arc length for the curve. |
| 6 | CubicTerm | OPTIONAL IfcLengthMeasure |
The constant that defines the cubic term in the equation which defines the relation between curvature and arc length for the curve. |
| 7 | QuadraticTerm | OPTIONAL IfcLengthMeasure |
The constant that defines the quadratic term in the equation which defines the relation between curvature and arc length for the curve. |
| 8 | LinearTerm | OPTIONAL IfcLengthMeasure |
The constant that defines the linear term in the equation which defines the relation between curvature and arc length for the curve. |
| 9 | ConstantTerm | OPTIONAL IfcLengthMeasure |
The constant that defines the constant term in the equation which defines the relation between curvature and arc length for the curve. |
8.9.3.63.4 Formal representation
ENTITY IfcSeventhOrderPolynomialSpiral
SUBTYPE OF (IfcSpiral);
SepticTerm : IfcLengthMeasure;
SexticTerm : OPTIONAL IfcLengthMeasure;
QuinticTerm : OPTIONAL IfcLengthMeasure;
QuarticTerm : OPTIONAL IfcLengthMeasure;
CubicTerm : OPTIONAL IfcLengthMeasure;
QuadraticTerm : OPTIONAL IfcLengthMeasure;
LinearTerm : OPTIONAL IfcLengthMeasure;
ConstantTerm : OPTIONAL IfcLengthMeasure;
END_ENTITY;