NurbsCurveCreateSpiral Method (Point3d, Vector3d, Point3d, Double, Double, Double, Double) |
Creates a C1 cubic NURBS approximation of a helix or spiral. For a helix,
you may have radius0 == radius1. For a spiral radius0 == radius1 produces
a circle. Zero and negative radii are permissible.
Namespace:
Rhino.Geometry
Assembly:
RhinoCommon (in RhinoCommon.dll)
Since: 5.2
Syntax public static NurbsCurve CreateSpiral(
Point3d axisStart,
Vector3d axisDir,
Point3d radiusPoint,
double pitch,
double turnCount,
double radius0,
double radius1
)
Public Shared Function CreateSpiral (
axisStart As Point3d,
axisDir As Vector3d,
radiusPoint As Point3d,
pitch As Double,
turnCount As Double,
radius0 As Double,
radius1 As Double
) As NurbsCurve
Parameters
- axisStart
- Type: Rhino.GeometryPoint3d
Helix's axis starting point or center of spiral. - axisDir
- Type: Rhino.GeometryVector3d
Helix's axis vector or normal to spiral's plane. - radiusPoint
- Type: Rhino.GeometryPoint3d
Point used only to get a vector that is perpendicular to the axis. In
particular, this vector must not be (anti)parallel to the axis vector.
- pitch
- Type: SystemDouble
The pitch, where a spiral has a pitch = 0, and pitch > 0 is the distance
between the helix's "threads".
- turnCount
- Type: SystemDouble
The number of turns in spiral or helix. Positive
values produce counter-clockwise orientation, negative values produce
clockwise orientation. Note, for a helix, turnCount * pitch = length of
the helix's axis.
- radius0
- Type: SystemDouble
The starting radius. - radius1
- Type: SystemDouble
The ending radius.
Return Value
Type:
NurbsCurveNurbsCurve on success, null on failure.
See Also