UV field might be blank/undefined

Some files have missing uv fields '1//1' instead of '1/1/1/'. We fall back to using uv 0 in this case.

Author: einarf

pywavefront/obj.py

@@ -378,7 +378,11 @@ def emit_vertex(vertex):
             for i, v in enumerate(self.values[1:]):
                 parts = v.split('/')
                 v_index = (int(parts[0]) - 1)
-                t_index = (int(parts[1]) - 1) if has_vt else None
+                # uv field might be blank
+                try:
+                    t_index = (int(parts[1]) - 1) if has_vt else None
+                except ValueError:
+                    t_index = 0
                 n_index = (int(parts[2]) - 1) if has_vn else None
 
                 # Resolve negative index lookups

tests/fixtures/simple_missing_uv.obj

@@ -0,0 +1,28 @@
+# Comment
+mtllib simple.mtl
+o Simple
+v 0.01 0.02 0.03
+v 0.04 0.05 0.06
+v 0.07 0.08 0.09
+v 0.11 0.12 0.13
+vt 10 11
+vt 12 13
+vt 14 15
+vt 16 17
+vn 20 21 22
+usemtl Material.simple
+f 2/3/1 1/2/1 3/1/1
+o SimpleB
+v 1.0 0.0 1.0
+v -1.0 0.0 1.0
+v 1.0 0.0 -1.0
+v -1.0 0.0 -1.0
+vt 0.0 1.0
+vt 0.0 0.0
+vt 1.0 0.0
+vt 1.0 1.0
+vn 0.0 1.0 0.0
+usemtl Material2.simple
+f 6/7/2 5/6/2 7/5/2
+f 6//2 5//2 7//2
+f 6/7/2 5/6/2 7/5/2

tests/test_parser.py

@@ -9,11 +9,13 @@
 
 
 class TestParsers(unittest.TestCase):
+
     def setUp(self):
         # Append current path to locate files
         meshes = pywavefront.Wavefront(fixture('simple.obj'))
         self.mesh1 = meshes.mesh_list[0]
         self.mesh2 = meshes.mesh_list[1]
+        self.maxDiff = None
 
     def testObjName(self):
         """Parsing an obj file with known names should set those names."""
@@ -43,6 +45,7 @@ def testObjMaterials(self):
         self.assertEqual(material1.name, 'Material.simple')
         self.assertEqual(material2.name, 'Material2.simple')
 
+
 class TestParserCollectFaces(unittest.TestCase):
     """Test collecting (possibly triangulated) faces"""
     def setUp(self):
@@ -102,6 +105,7 @@ def test_missing_material_create(self):
 
 
 class TestParserVertexVariants(unittest.TestCase):
+    maxDiff = None
 
     def testObjNoNormals(self):
         """Parse obj without normals"""
@@ -174,6 +178,27 @@ def testObjColors(self):
 
         self.assertEqual(self.mesh2.materials[0].vertex_format, "T2F_C3F_N3F_V3F")
 
+    def test_undefined_uvs(self):
+        """obj file were some uv entries are undefiend"""
+        meshes = pywavefront.Wavefront(fixture('simple_missing_uv.obj'))
+        self.mesh2 = meshes.mesh_list[1]
+
+        self.assertEqual(self.mesh2.materials[0].vertices, [
+            1.0, 0.0, 0.0, 1.0, -0.0, -1.0, 0.0, 1.0,
+            0.0, 0.0, 0.0, 1.0, -0.0, 1.0, 0.0, 1.0,
+            0.0, 1.0, 0.0, 1.0, -0.0, 1.0, 0.0, -1.0,
+
+            10.0, 11.0, 0.0, 1.0, -0.0, -1.0, 0.0, 1.0,
+            10.0, 11.0, 0.0, 1.0, -0.0, 1.0, 0.0, 1.0,
+            10.0, 11.0, 0.0, 1.0, -0.0, 1.0, 0.0, -1.0,
+
+            1.0, 0.0, 0.0, 1.0, -0.0, -1.0, 0.0, 1.0,
+            0.0, 0.0, 0.0, 1.0, -0.0, 1.0, 0.0, 1.0,
+            0.0, 1.0, 0.0, 1.0, -0.0, 1.0, 0.0, -1.0,
+        ])
+
+        self.assertEqual(self.mesh2.materials[0].vertex_format, "T2F_N3F_V3F")
+
 
 class TestMtlParser(unittest.TestCase):
     def setUp(self):