obj
What is a .obj file?
model/obj
OBJ (Wavefront OBJ) is a text-based 3D geometry format defining vertices, texture coordinates, normals, and faces, and referencing materials through a companion MTL file. It is simple, widely supported, and can represent polygonal meshes with UV mapping. It is a common interchange format across 3D tools.
How to use a .obj file
Use an example OBJ to test mesh and UV parsing, MTL material resolution, and importers in 3D engines, renderers, and modeling applications.
Download example .obj files
- OBJ: Wavefront CubeA 10 mm cube as a Wavefront OBJ, plain-text vertices and triangular faces, the lingua franca of 3D asset exchange. For testing OBJ importers and conversion.
- OBJ: Textured Mini QuadWavefront OBJ textured quad SAMPLE with MTL reference.
- OBJ: PBR Sphere referencing an MTLA smooth-shaded sphere as Wavefront OBJ with `mtllib`/`usemtl` pointing at a sibling MTL. Downloading the OBJ alone gives you the classic missing-material case; downloading both reproduces the glTF metallic-roughness twin in this group.
- OBJ: Clean Reference CubeA welded, manifold, consistently-wound unit cube: 8 vertices, 12 triangles, 18 edges each shared by exactly two faces, and a signed volume of exactly 1.0. This is the answer key: each defect fixture in the degenerate/ subcategory is this mesh with exactly one thing wrong.
- OBJ: Zero-area TrianglesThe reference cube plus four triangles with no area, one for each way a mesh can have one: three collinear points, two coincident vertices at different indices, a repeated index, and all three indices identical. Their face normals are undefined, which is where downstream tools produce NaN.
- OBJ: Duplicate Vertices, Split SeamThe reference cube with all eight corners stored twice at bit-identical coordinates: the first six triangles use one copy, the last six use the other. It renders as a closed cube but is topologically two disconnected surface patches with a split seam, which is why smoothing, subdivision and boolean operations all misbehave on it.
- OBJ: Non-manifold Edge (three faces on one edge)The reference cube with a two-triangle fin welded along one top edge, so that edge is shared by three faces instead of two. Non-manifold edges have no defined surface orientation, which is why slicers refuse them and why subdivision and offsetting produce garbage.
- OBJ: Inverted Normals / Mixed WindingThe reference cube with three of its six cube faces (six of its twelve triangles) wound clockwise instead of counter-clockwise, and `vn` records that follow the reversed winding into the solid. The classic symptom is a model that looks half-invisible with backface culling on and half-black with it off.
and 16 more in the library.