Adding Curvature Circles
This guide demonstrates how to add curvature circles using RhinoScript.
Rhino’s Curvature command is very useful for analyzing the curvature at a point on a curve. This script shows how to add the circle to the document when the curve is picked (instead of just drawing it dynamically).
There is no option on the Curvature command for leaving the circle that it draw dynamically. But, with the help of a script, you can write a subroutine that will. The following example demonstrates how to do just this.
Option Explicit Sub CurvatureCircle Dim crv, crv_pt, crv_t Dim arr, crv_pl, pl crv = Rhino.GetObject("Select curve for curvature measurement", 4, True) If IsNull(crv) Then Exit Sub Do crv_pt = Rhino.GetPointOnCurve(crv, "Select point on curve for curvature measurement") If IsNull(crv_pt) Then Exit Do crv_t = Rhino.CurveClosestPoint(crv, crv_pt) If IsNull(crv_t) Then Exit Do arr = Rhino.CurveCurvature(crv, crv_t) If IsNull(arr) Then Rhino.Print("Unable to compute curve curvature.") Exit Do End If crv_pl = Rhino.PlaneFromFrame(arr(0), arr(1), arr(4)) pl = Rhino.MovePlane(crv_pl, arr(2)) Rhino.AddCircle pl, arr(3) Rhino.AddPoint arr(0) Loop While Not IsNull(crv_pt) End Sub