The OBJ file format is a widely used file format for 3D computer graphics and 3D printing applications. It is used to store 3D models and their associated geometry, texture coordinates, vertex normals, and material properties.

Here are key points about OBJ files:

  1. Text-Based: OBJ files are text-based, which means they can be viewed and edited using a simple text editor. This makes them human-readable and easy to work with.
  2. Geometry: OBJ files can describe the geometry of 3D models, including vertices (points in 3D space), faces (triangles or polygons formed by connecting vertices), and vertex normals (vectors that define the orientation of the surface at each vertex).
  3. Textures and Materials: OBJ files can also reference external texture maps and material libraries. This allows 3D models to be textured and have associated material properties such as color, reflectivity, and transparency.
  4. Grouping and Smoothing: OBJ files support the grouping of objects and smoothing groups, which can be used to control how the surface of a 3D model appears smooth or faceted.
  5. Wavefront OBJ: OBJ stands for “Wavefront Object,” and it was originally developed by Wavefront Technologies for their Advanced Visualizer software. It has since become a widely supported file format in the computer graphics industry.
  6. Compatibility: OBJ files are compatible with a wide range of 3D modeling and rendering software. They are often used for exchanging 3D models between different applications.
  7. 3D Printing: OBJ files can be used for 3D printing, just like STL files. Many 3D printers and slicing software can work with OBJ files, especially when they contain watertight and manifold geometry.
  8. Limitations: While OBJ files are versatile, they may not support advanced features found in other formats, such as rigging and animation data. Additionally, OBJ files can become quite large when storing high-resolution textures and complex geometry.
  9. Multipart OBJ: OBJ files can store multiple 3D objects in a single file, each with its own geometry and material properties. This makes them suitable for creating complex scenes.
  10. Customization: Users can create and edit OBJ files using 3D modeling software. This allows for customization, modification, and creation of 3D models for various applications, including animation, gaming, visualization, and 3D printing.

OBJ files are a versatile and widely supported format for 3D modeling and rendering, making them a common choice for exchanging and sharing 3D models in the computer graphics industry.