M_Rhino_Geometry_Curve_PointAtLength

Curve.PointAtLength Method

Gets a point at a certain length along the curve. The length must be non-negative and less than or equal to the length of the curve. Lengths will not be wrapped when the curve is closed or periodic.

Namespace: Rhino.Geometry
Assembly: RhinoCommon (in RhinoCommon.dll) Version: Rhino 6.0

Syntax

C#

public Point3d PointAtLength(
	double length
)

VB

Public Function PointAtLength ( 
	length As Double
) As Point3d

Parameters

 

length

Type: System.Double
Length along the curve between the start point and the returned point.

Return Value

Type: Point3d
Point on the curve at the specified length from the start point or Poin3d.Unset on failure.

Examples

VB

Partial Class Examples
  Public Shared Function ArcLengthPoint(ByVal doc As Rhino.RhinoDoc) As Rhino.Commands.Result
    Dim objref As Rhino.DocObjects.ObjRef = Nothing
    Dim rc As Rhino.Commands.Result = Rhino.Input.RhinoGet.GetOneObject("Select curve", True, Rhino.DocObjects.ObjectType.Curve, objref)
    If rc <> Rhino.Commands.Result.Success Then
      Return rc
    End If
    Dim crv As Rhino.Geometry.Curve = objref.Curve()
    If crv Is Nothing Then
      Return Rhino.Commands.Result.Failure
    End If

    Dim crv_length As Double = crv.GetLength()
    Dim length As Double = 0
    rc = Rhino.Input.RhinoGet.GetNumber("Length from start", True, length, 0, crv_length)
    If rc <> Rhino.Commands.Result.Success Then
      Return rc
    End If

    Dim pt As Rhino.Geometry.Point3d = crv.PointAtLength(length)
    If pt.IsValid Then
      doc.Objects.AddPoint(pt)
      doc.Views.Redraw()
    End If
    Return Rhino.Commands.Result.Success
  End Function
End Class

C#

partial class Examples
{
  public static Rhino.Commands.Result ArcLengthPoint(Rhino.RhinoDoc doc)
  {
    Rhino.DocObjects.ObjRef objref;
    Rhino.Commands.Result rc = Rhino.Input.RhinoGet.GetOneObject("Select curve",
      true, Rhino.DocObjects.ObjectType.Curve,out objref);
    if(rc!= Rhino.Commands.Result.Success)
      return rc;
    Rhino.Geometry.Curve crv = objref.Curve();
    if( crv==null )
      return Rhino.Commands.Result.Failure;

    double crv_length = crv.GetLength();
    double length = 0;
    rc = Rhino.Input.RhinoGet.GetNumber("Length from start", true, ref length, 0, crv_length);
    if(rc!= Rhino.Commands.Result.Success)
      return rc;

    Rhino.Geometry.Point3d pt = crv.PointAtLength(length);
    if (pt.IsValid)
    {
      doc.Objects.AddPoint(pt);
      doc.Views.Redraw();
    }
    return Rhino.Commands.Result.Success;
  }
}

Python

import Rhino
import scriptcontext

def ArcLengthPoint():
    rc, objref = Rhino.Input.RhinoGet.GetOneObject("Select curve", True, Rhino.DocObjects.ObjectType.Curve)
    if rc!=Rhino.Commands.Result.Success: return rc
    crv = objref.Curve()
    if not crv: return Rhino.Commands.Result.Failure
    crv_length = crv.GetLength()
    length = 0
    rc, length = Rhino.Input.RhinoGet.GetNumber("Length from start", True, length, 0, crv_length)
    if rc!=Rhino.Commands.Result.Success: return rc
    pt = crv.PointAtLength(length)
    if pt.IsValid:
        scriptcontext.doc.Objects.AddPoint(pt)
        scriptcontext.doc.Views.Redraw()
    return Rhino.Commands.Result.Success

if __name__=="__main__":
    ArcLengthPoint()

Version Information

Supported in: 6.0.16224.21491, 5D58w

See Also

Reference

Curve Class
Rhino.Geometry Namespace