SplitFaceRadial.py

import rhinoscriptsyntax  as rs
import scriptcontext as sc
import Rhino

def RadialSplit():

    blnDel = True
    
    while True:
        if sc.sticky.has_key('DELETE_SPLIT'):
            blnDel  = sc.sticky['DELETE_SPLIT']
        
        go = Rhino.Input.Custom.GetObject()
        go.GeometryFilter = Rhino.DocObjects.ObjectType.Surface
        go.SetCommandPrompt("Select surface to split")
        opDel = Rhino.Input.Custom.OptionToggle(blnDel,'No', 'Yes')
        go.AddOptionToggle("DeleteInput", opDel)
        
        rc = go.Get()
        if go.CommandResult() != Rhino.Commands.Result.Success:
            return go.CommandResult()
            
        if rc == Rhino.Input.GetResult.Option:
            blnDel = opDel.CurrentValue
            sc.sticky['DELETE_SPLIT'] = blnDel
            continue
        if rc == Rhino.Input.GetResult.Object:
            objref = go.Object(0)
            idx = objref.GeometryComponentIndex.Index
            id = go.Object(0).ObjectId
            break
            
    if not id: return
    
    tol = sc.doc.ModelAbsoluteTolerance
    geo = sc.doc.Objects.Find(id).BrepGeometry
    
    if idx == -1: idx = 0
    
    face = geo.Faces[idx]
    if not face.IsPlanar():
        print "The selected face is not planar. Nothing done."
        return
    trims = [face.OuterLoop.Trims[n].Edge.EdgeCurve for n in range(face.OuterLoop.Trims.Count)] 
    
    border = Rhino.Geometry.Curve.JoinCurves(trims)[0]
    border = border.Simplify(Rhino.Geometry.CurveSimplifyOptions.All,tol, sc.doc.ModelAngleToleranceRadians    

    if border.IsClosable(tol*10):
        border.MakeClosed(tol)
    #sc.doc.Objects.AddCurve(border)
      
    mp  = Rhino.Geometry.AreaMassProperties.Compute(border)
    
    if not mp:
        print "Error locating centroid"
        return
    
    pt = mp.Centroid
    pts = []
    for trim in trims:
        pts.append(trim.PointAtStart)
        pts.append(trim.PointAtEnd)
     
    pts = Rhino.Geometry.Point3d.CullDuplicates(pts, tol)
    
    lines  = [Rhino.Geometry.LineCurve(point, pt) for point in pts]
    
    brep = face.Split(lines, tol)
    
    if brep:
        brep.Compact()
        if blnDel:
            sc.doc.Objects.Replace(id, brep)
        else:
            sc.doc.Objects.AddBrep(brep)
    sc.doc.Views.Redraw()
    
    
if __name__ == '__main__':RadialSplit()