docs: def export_mesh(vertices, triangles, filename, mesh_name="mcubes_mesh"):
      """
      Exports a mesh in the COLLADA (.dae) format.
      
      Needs PyCollada (https://github.com/pycollada/pycollada).
      """
      
      import collada
      
      mesh = collada.Collada()
      
      vert_src = collada.source.FloatSource("verts-array", vertices, ('X','Y','Z'))
      geom = collada.geometry.Geometry(mesh, "geometry0", mesh_name, [vert_src])
      
      input_list = collada.source.InputList()
      input_list.addInput(0, 'VERTEX', "#verts-array")
      
      triset = geom.createTriangleSet(np.copy(triangles), input_list, "")
      geom.primitives.append(triset)
      mesh.geometries.append(geom)
      
      geomnode = collada.scene.GeometryNode(geom, [])
      node = collada.scene.Node(mesh_name, children=[geomnode])
      
      myscene = collada.scene.Scene("mcubes_scene", [node])
      mesh.scenes.append(myscene)
      mesh.scene = myscene
      
      mesh.write(filename)