What is OBJ?

OBJ files store 3D geometry data in a simple text format. Each line defines vertices (v), texture coordinates (vt), normals (vn), or faces (f). OBJ files often come with .mtl (material) files that define surface properties like color, texture maps, and reflectivity. The format is human-readable and can be edited in any text editor.

OBJ is used for 3D modeling exchange between software (Blender, Maya, 3ds Max), 3D printing preparation, game asset development, and AR/VR applications. It's the standard interchange format when moving models between different 3D programs. Unlike proprietary formats (FBX, BLEND), OBJ is open and universally supported, making it ideal for collaboration and archiving.

Did you know? OBJ is the most universal 3D format - supported by virtually every 3D software!

History

Wavefront Technologies created OBJ for their Advanced Visualizer software, and it became an industry standard due to its simplicity and openness.

Key Milestones

  • 1980s: OBJ format created by Wavefront
  • 1994: Widely adopted in 3D industry
  • 2000s: Standard for software interchange
  • 2010: Used in 3D printing workflows
  • 2015: AR/VR applications adopt OBJ
  • Present: Universal 3D exchange format

Key Features

Core Capabilities

  • Text-Based: Human-readable format
  • Geometry: Vertices, faces, normals
  • UV Mapping: Texture coordinates
  • Materials: MTL file support
  • Groups: Object organization
  • Universal: All 3D software supports

Common Use Cases

3D Exchange

Between software packages

3D Printing

Model preparation

Game Assets

Model import/export

AR/VR

3D content creation

Advantages

  • Universal software compatibility
  • Simple and open format
  • Human-readable text
  • Easy to parse and edit
  • Good for interchange
  • Supports materials and textures
  • Industry standard for decades

Disadvantages

  • No animation support
  • No scene hierarchy
  • Large file sizes (text format)
  • Limited material capabilities
  • No lighting or camera data
  • Slower to load than binary

Technical Information

Format Specifications

Specification Details
File Extension .obj (geometry), .mtl (materials)
MIME Type model/obj, text/plain
Format Type Text-based 3D geometry
Content Vertices, faces, UVs, normals
Coordinate System Right-handed (default)
Typical Size 1-100 MB

Common Tools

  • 3D Software: Blender, Maya, 3ds Max, Cinema 4D
  • Viewers: MeshLab, Windows 3D Viewer, Online OBJ viewers
  • Converters: Assimp, FBX Converter, Blender
  • Editors: MeshLab, MeshMixer, CloudCompare