From 8b3ba6ede4c489635ca6cb97fbb112755c933abf Mon Sep 17 00:00:00 2001 From: Raashish Aggarwal <94279692+raashish1601@users.noreply.github.com> Date: Mon, 19 Oct 2026 14:36:14 -0700 Subject: [PATCH] Accept tab-separated lines in load_obj (#2061) Summary: `load_obj` recognizes vertex, texture, normal and face lines with `line.startswith("v ")`, `"vt "`, `"vn "` and `"f "`. The OBJ format separates fields with any whitespace, and some exporters write a tab after the keyword. Those lines are skipped without any error, so the mesh silently loses vertices and faces: ```python from io import StringIO from pytorch3d.io import load_obj verts, faces, _ = load_obj(StringIO("v\t0 0 0\nv 1 0 0\nv 0 1 0\nf\t1 2 3\n")) verts.shape, faces.verts_idx.shape # before: (2, 3), (0, 3) after: (3, 3), (1, 3) ``` This dispatches on the first token of the already split line (`tokens[:1] == ["v"]`), the same way the `usemtl` branch already does. Pull Request resolved: https://github.com/facebookresearch/pytorch3d/pull/2061 Test Plan: added `test_load_obj_tab_separated` to `tests/test_io_obj.py`, using tabs in `v`, `vt`, `vn` and `f` lines. It fails on main and passes with the change. I ran `tests/test_io_obj.py` on Windows without the C++ extension: the same 19 tests fail before and after (they reopen a `NamedTemporaryFile` or need `_C`), and the rest pass. flake8 is clean on the changed lines. Reviewed By: MichaelRamamonjisoa Differential Revision: D124656223 Pulled By: bottler fbshipit-source-id: ab0ef3dc0f3c998c44874e6a416e6a9649f29378 --- pytorch3d/io/obj_io.py | 8 ++++---- tests/test_io_obj.py | 23 +++++++++++++++++++++++ 2 files changed, 27 insertions(+), 4 deletions(-) diff --git a/pytorch3d/io/obj_io.py b/pytorch3d/io/obj_io.py index 9e2e2e7f..36b6ff53 100644 --- a/pytorch3d/io/obj_io.py +++ b/pytorch3d/io/obj_io.py @@ -472,26 +472,26 @@ def _parse_obj(f, data_dir: str): materials_idx = len(material_names) - 1 else: materials_idx = material_names.index(material_name) - elif line.startswith("v "): # Line is a vertex. + elif tokens[:1] == ["v"]: # Line is a vertex. vert = [float(x) for x in tokens[1:4]] if len(vert) != 3: msg = "Vertex %s does not have 3 values. Line: %s" raise ValueError(msg % (str(vert), str(line))) verts.append(vert) - elif line.startswith("vt "): # Line is a texture. + elif tokens[:1] == ["vt"]: # Line is a texture. tx = [float(x) for x in tokens[1:3]] if len(tx) != 2: raise ValueError( "Texture %s does not have 2 values. Line: %s" % (str(tx), str(line)) ) verts_uvs.append(tx) - elif line.startswith("vn "): # Line is a normal. + elif tokens[:1] == ["vn"]: # Line is a normal. norm = [float(x) for x in tokens[1:4]] if len(norm) != 3: msg = "Normal %s does not have 3 values. Line: %s" raise ValueError(msg % (str(norm), str(line))) normals.append(norm) - elif line.startswith("f "): # Line is a face. + elif tokens[:1] == ["f"]: # Line is a face. # Update face properties info. _parse_face( line, diff --git a/tests/test_io_obj.py b/tests/test_io_obj.py index eb379ea5..1d483640 100644 --- a/tests/test_io_obj.py +++ b/tests/test_io_obj.py @@ -319,6 +319,29 @@ class TestMeshObjIO(TestCaseMixin, unittest.TestCase): self.assertTrue(materials is None) self.assertTrue(tex_maps is None) + def test_load_obj_tab_separated(self): + # Tabs are whitespace too, including between the keyword and the values. + obj_file = "\n".join( + [ + "v\t0.1\t0.2\t0.3", + "v 0.2 0.3 0.4", + "v\t0.3 0.4 0.5", + "vt\t0.5\t0.5", + "vn\t0.0\t0.0\t1.0", + "f\t1/1/1\t2/1/1\t3/1/1", + ] + ) + verts, faces, aux = load_obj(StringIO(obj_file)) + expected_verts = torch.tensor( + [[0.1, 0.2, 0.3], [0.2, 0.3, 0.4], [0.3, 0.4, 0.5]], dtype=torch.float32 + ) + self.assertClose(verts, expected_verts) + self.assertClose(faces.verts_idx, torch.tensor([[0, 1, 2]])) + self.assertClose(faces.textures_idx, torch.tensor([[0, 0, 0]])) + self.assertClose(faces.normals_idx, torch.tensor([[0, 0, 0]])) + self.assertClose(aux.verts_uvs, torch.tensor([[0.5, 0.5]])) + self.assertClose(aux.normals, torch.tensor([[0.0, 0.0, 1.0]])) + def test_load_obj_error_textures(self): obj_file = "\n".join(["vt 0.1"]) with NamedTemporaryFile(mode="w", suffix=".obj") as f: