OBJ

It stores geometric data such as points, lines, and surfaces in a text-based format and is often used for 3D graphics. The OBJ format does not support animation or materials, but it is widely used and compatible with many programs.

What is the OBJ format?

The OBJ file format was originally developed by Wavefront Technologies and has become the standard for 3D graphics. It is used to store 3D models and is supported by a wide range of applications. It is particularly useful for modelling and 3D printing.

Why is the OBJ format important?

The OBJ format is characterized by its simplicity and flexibility. It allows 3D geometry to be stored in a text-based format that is easy to read and edit. These features make it a popular format for exchanging 3D data between different applications and platforms.

How is the OBJ format used?

The use of OBJ files ranges from creating complex 3D models in CAD programs to integrating these models into game engines or 3D printing software. As the format does not contain animation or lighting information, it is particularly suitable for static models.

Advantages of the OBJ format

A major advantage of the OBJ format is its cross-platform support. Almost all modern 3D applications can import and export OBJ files. In addition, the format is easy to use due to its text-based structure, making it ideal for developing and testing 3D projects.

Limitations of the OBJ format

Despite its advantages, the OBJ format has its limitations. It does not store information about animation or complex material properties that are available in more advanced formats such as FBX or GLTF.

As a result, it is often used only to exchange basic geometry, while other formats are preferred for more complex scenes.

Facts and features

• Text-based format: Based on plain text, it can be opened and edited in a text editor.
• Supports polygon models: OBJ files mainly store polygon models such as triangles and quadrilaterals.
• Widely used in the CGI industry: It is widely used in the film and games industry to exchange models between different applications.
• Accompanying Material File: An additional MTL file is typically used to store information about materials and textures.
• 3D printing: OBJ files are widely supported and used by 3D printing software.
• No compression: OBJ files are uncompressed, which can result in larger file sizes compared to other formats.
• Point clouds: The format can store point clouds as well as surfaces and edges.
• Multi-object support: Multiple separate objects can be defined and stored in an OBJ file.
• No hierarchies: Unlike formats such as FBX, OBJ does not support hierarchies based on rigging, making it less suitable for animated models.

Frequently Asked Questions

Can OBJ files contain textures?
Yes, OBJ files can contain textures, but only indirectly. Information about materials and textures is stored in a separate MTL file that is associated with the OBJ file.

How big are OBJ files compared to other formats?
OBJ files can be relatively large as they are not compressed. They explicitly store each point and surface, resulting in a larger file size compared to compressed formats.

Is the OBJ format suitable for animation?
No, the OBJ format does not store animation data. It is only intended to store static 3D models and does not support rigging or animation data.

What programs support the OBJ format?
Almost all popular 3D applications such as Blender, Maya, 3ds Max and even some game engines such as Unity and Unreal support the import and export of OBJ files.

How are OBJ files used in the real world?
OBJ files are often used to exchange 3D models between different programs or to prepare them for 3D printing. They are also popular in the CGI world for integrating models into different workflows.