Find the local exteremes of a periodic boundary

Grasshopper
1

Hello Everyone,
I’m looking for a way to find the local extremes of a periodic boundary. When I choose to work with periodic boundary the extremes can be found in several directions (I used RhinoCurveExtremeParameters method). Does anyone have any idea how to find local extremes of a periodic curve without optimization solvers?
P.S I’m not sure if those points are called local extremes.
Best,

Mahan

Periodic boundary
Periodic boundary1240×620 51.4 KB

2

I guess you’re looking for MaxCurvaturePoints:

image
image1333×750 66 KB 

private void RunScript(Curve curve, ref object A)
{
  A = curve.MaxCurvaturePoints();
}

MaxCurvature.gh (3.3 KB)

2 Likes
3

Hi Mahdiyar. Is that a custom made function? Because it doesn’t exist in my library.

Best,

Mahan

4

It’s only available in Rhino 7 WIP.

5

So then it’s the question how we can have it in Rhino 6? Maybe there is a way if we can understand the mathematical solution.

6

MaxCurvature(Rhino 6).gh (4.9 KB)

source: https://github.com/mcneel/rhino-developer-samples/blob/6/rhinocommon/cs/SampleCsCommands/SampleCsExtractMinMaxRadiusPoints.cs

2 Likes
7

extreme_curvature_2020May19a
extreme_curvature_2020May19a1340×475 48.1 KB

extreme_curvature_2020May19a.gh (9.5 KB)

from Curve.MaxCurvaturePoints Method:

The maximum curvature points identify where the curvature starts to decrease in both directions from the points.

3 Likes
8

Thanks Joseph. it works well.

Best,
Mahan