Convex hull division using Fiedler vectors

.py

# %%
import bpy
import networkx as nx  # /path/to/blender's/python -m pip install scipy networkx
import numpy as np
from scipy.spatial import ConvexHull


def obj2GraphAndXyzAndNormFiedler(obj):
    edges = [(e.vertices[0], e.vertices[1]) for e in obj.data.edges]
    G = nx.Graph(edges)
    xyz = dict(zip(G.nodes, [obj.data.vertices[i].co for i in G.nodes]))
    S = [G.subgraph(c).copy() for c in nx.connected_components(G)]
    G = S[0]
    fiedler_vector = nx.fiedler_vector(G)
    minV, maxV = min(fiedler_vector), max(fiedler_vector)
    width = maxV-minV
    norm_fiedler = [(v-minV)/width for v in fiedler_vector]
    return G, xyz, norm_fiedler


def GraphAndXyzAndCategory2MeshLys(G, xyz, category):
    subnodeLys = [[n for n, target in zip(G.nodes, category) if target == c] for c in range(k)]
    subgraphLys = [[G.subgraph(c).copy() for c in nx.connected_components(G.subgraph(subnodes))]
                   for subnodes in subnodeLys]
    hullLys = [[ConvexHull([xyz[n] for n in H.nodes]) for H in subgraphLy]for subgraphLy in subgraphLys]
    meshLys = [[{'verts': hull.points, 'faces': hull.simplices} for hull in hullLy] for hullLy in hullLys]
    return meshLys


def addObjectWithMesh(name, verts, faces, collection='Collection'):
    mesh = bpy.data.meshes.new(name)
    obj = bpy.data.objects.new(mesh.name, mesh)
    col = bpy.data.collections[collection]
    col.objects.link(obj)
    bpy.context.view_layer.objects.active = obj
    mesh.from_pydata(verts, [], faces)
    return obj


# %%
objName = 'bun_zipper'
obj = bpy.data.objects[objName]
G, xyz, norm_fiedler = obj2GraphAndXyzAndNormFiedler(obj)

# %%
k = 24
category = [int(np.floor(v * k)) for v in norm_fiedler]
category = [k-1 if c == k else c for c in category]
meshLys = GraphAndXyzAndCategory2MeshLys(G, xyz, category)

# %%
collection_name = f'{objName}_parts'
if collection_name not in bpy.data.collections:
    collection = bpy.data.collections.new(collection_name)
    bpy.context.scene.collection.children.link(collection)
for i, meshLy in enumerate(meshLys):
    for j, mesh in enumerate(meshLy):
        newObj = addObjectWithMesh(
            f'{objName}_part_{i}_{j}',
            mesh['verts'],
            mesh['faces'],
            collection=collection_name)
        newObj.location = obj.location
        newObj.rotation_euler = obj.rotation_euler
        newObj.scale = obj.scale

# %%