Upload a mesh with part segmentation. We recommend using these segmentation tools:
import trimesh
import numpy as np
mesh = trimesh.load("mesh.glb", force="mesh")
mask_npy = np.load("mask.npy")
mesh_parts = []
for part_id in np.unique(mask_npy):
mesh_part = mesh.submesh([mask_npy == part_id], append=True)
mesh_parts.append(mesh_part)
mesh_parts = trimesh.Scene(mesh_parts).export("input_mesh.glb")