code: def _load_texture_images(
      material_names: List[str],
      data_dir: str,
      material_properties: MaterialProperties,
      texture_files: TextureFiles,
      path_manager: PathManager,
  ) -> Tuple[MaterialProperties, TextureImages]:
      final_material_properties = {}
      texture_images = {}
  
      used_material_names = list(material_names)
      if not used_material_names and material_properties:
          if len(material_properties) > 1:
              raise ValueError(
                  "Multiple materials but no usemtl declarations in the obj file"
              )
          # No materials were specified in obj file and only one is in the
          # specified .mtl file, so we use it.
          used_material_names.append(
              next(iter(material_properties.keys()))
          )
  
      # Only keep the materials referenced in the obj.
      for material_name in used_material_names:
          if material_name in texture_files:
              # Load the texture image.
              path = os.path.join(
                  data_dir, texture_files[material_name]
              )
              if path_manager.exists(path):
                  image = (
                      _read_image(
                          path, path_manager=path_manager, format="RGB"
                      )
                      / 255.0
                  )
                  image = torch.from_numpy(image)
                  texture_images[material_name] = image
              else:
                  msg = f"Texture file does not exist: {path}"
                  warnings.warn(msg)
  
          if material_name in material_properties:
              final_material_properties[
                  material_name
              ] = material_properties[material_name]
  
      return final_material_properties, texture_images
  
file_path: pytorch3d/pytorch3d/io/mtl_io.py
imports: import os
  import warnings
  from typing import Dict, List, Optional, Tuple
  import numpy
  import torch
  import torch.nn.functional
  from iopath.common.file_io import PathManager
  from pytorch3d.common.compat import meshgrid_ij
  from pytorch3d.common.datatypes import Device
  from pytorch3d.io.utils import _open_file, _read_image
label_desc: Use image node_id 6 for calling a global function with example usage: _load_texture_images(material_names, data_dir, material_properties, texture_files, path_manager) and returns: final_material_properties,  texture_images