| Extension | F3D |
| Full Name | Fusion 360 |
| Type | CAD |
| Mime Type | application/octet-stream |
| Format | Binary |
The F3D format is a purpose-built file format created by Autodesk for use with their Fusion 360 Computer Aided Design (CAD) software. Fusion 360 is popular for use in various engineering and manufacturing sectors, with the format continuing to evolve with new features added with each new release.
Contained within an F3D file is the 3D object, along with its associate elements. These are defined in a manner that incorporates a complete history of the object, allowing adjustments to be made to earlier parts of the object while maintaining the final valid 3D model.
As F3D files can only be opened using Fusion 360, support for opening these files with other software is limited. Fusion 360 does offer export options for STEP, STL, and other popular formats, meaning F3D files can be indirectly converted to other formats and consumed by other CAD applications relatively easily.
The OBJ file format is a 3D graphics file format used to define complex 3D models, including geometry, materials, and textures. OBJ files are text files, making them human-readable and easy to modify by hand. The downside to this ease of readability is that the files can become rather large when dealing with large or complex 3D models.
As mentioned, the OBJ format stores not only 3D model geometry but also materials and textures. These materials are usually defined in a separate file with the MTL file extension and specify geometry rendering details such as diffuse and specular colour, transparency, and much more.
The OBJ material file can also reference external texture files. These are usually JPEG or PNG files; however, these can be older formats, such as TGA. Where materials are used, the OBJ file will also contain material names preceding the geometry faces they should be applied to. If textures are referenced, the geometry will also contain texture coordinates (UV) for each vertex.
