Shortest

Given a mesh and two vertex indices find the shortest path between the two vertices while only traveling along edges of the mesh using a distance-weighted graph search.

import trimesh
import numpy as np
import networkx as nx

# test on a sphere mesh
mesh = trimesh.primitives.Sphere()

# edges without duplication
edges = mesh.edges_unique

# the actual length of each unique edge
length = mesh.edges_unique_length

# create the graph with edge attributes for length
g = nx.Graph()
for edge, L in zip(edges, length):
    g.add_edge(*edge, length=L)

# arbitrary indices of mesh.vertices to test with
start = 0
end = int(len(mesh.vertices) / 2.0)

# run the shortest path query using length for edge weight
path = nx.shortest_path(g,
                        source=start,
                        target=end,
                        weight='length')

# VISUALIZE RESULT
# make the sphere white
mesh.visual.face_colors = [255,255,255,255]
# Path3D with the path between the points
path_visual = trimesh.load_path(mesh.vertices[path])

# create a scene with the mesh, path, and points
scene = trimesh.Scene([path_visual, mesh ])

scene.show()