PathManager passing

Summary:
Make no internal functions inside pytorch3d/io interpret str paths except using a PathManager from iopath which they have been given. This means we no longer use any global PathManager object and we no longer use fvcore's deprecated file_io.

To preserve the APIs, various top level functions create their own default-initialized PathManager object if they are not provided one.

Reviewed By: theschnitz

Differential Revision: D25372969

fbshipit-source-id: c176ee31439645fa54a157d6f1aef18b09501569

tests/test_obj_io.py

@@ -8,6 +8,7 @@ from pathlib import Path
 
 import torch
 from common_testing import TestCaseMixin
+from iopath.common.file_io import PathManager
 from pytorch3d.io import load_obj, load_objs_as_meshes, save_obj
 from pytorch3d.io.mtl_io import (
     _bilinear_interpolation_grid_sample,
@@ -460,7 +461,9 @@ class TestMeshObjIO(TestCaseMixin, unittest.TestCase):
             ]
         )
         mtl_file = StringIO(mtl_file)
-        material_properties, texture_files = _parse_mtl(mtl_file, device="cpu")
+        material_properties, texture_files = _parse_mtl(
+            mtl_file, path_manager=PathManager(), device="cpu"
+        )
 
         dtype = torch.float32
         expected_materials = {

tests/test_ply_io.py

@@ -5,12 +5,21 @@ import unittest
 from io import BytesIO, StringIO
 from tempfile import TemporaryFile
 
+import pytorch3d.io.ply_io
 import torch
 from common_testing import TestCaseMixin
-from pytorch3d.io.ply_io import _load_ply_raw, load_ply, save_ply
+from iopath.common.file_io import PathManager
+from pytorch3d.io.ply_io import load_ply, save_ply
 from pytorch3d.utils import torus
 
 
+global_path_manager = PathManager()
+
+
+def _load_ply_raw(stream):
+    return pytorch3d.io.ply_io._load_ply_raw(stream, global_path_manager)
+
+
 class TestMeshPlyIO(TestCaseMixin, unittest.TestCase):
     def test_raw_load_simple_ascii(self):
         ply_file = "\n".join(