Python, a high-performance concave hull

[Danielm103]

https://github.com/mapbox/concaveman

https://github.com/sadaszewski/concaveman-cpp

 

it’s not automatic in that it requires parameters depending on the point distribution.

 

concavity: A relative measure of concavity. A value of 1 provides a detailed shape, while Infinity results in a convex hull.

lengthThreshold: Determines the minimum segment length considered for further detailing, with higher values leading to simpler shapes.   

 

Chomped through this 280k point set

 

import traceback
from pyrx import Ap, Db, Ed, Ge
 
# --- Command for PyRx ---
@Ap.Command()
def doit0():
    try:
        ps, ss = Ed.Editor.select([(Db.DxfCode.kDxfStart, "POINT")])
        pnts = Ge.Point3dArray([Db.Point(id).position() for id in ss])
        hull_points = pnts.concaveHull(0.8, 100)
        
        db = Db.curDb()
        pl = Db.Polyline(hull_points)
        pl.setDatabaseDefaults()
        pl.setClosed(True)
        pl.setColorIndex(2)
        db.addToModelspace(pl)
        
    except Exception:
        traceback.print_exc()