| Extension | PDF |
| Full Name | Portable Document Format |
| Type | Document |
| Mime Type | application/pdf |
| Format | Binary |
PDF documents have been around for many years, becoming the standard format for storing and transmitting documents with rich content such as formatted text, images, tables, and other complex formatting. The format is still under development, with new features being added with each revision.
One of the reasons for its widespread adoption is its ability to store all the required document components, especially fonts, within a single file, allowing the document to be rendered equally on different platforms and devices.
PDF documents are read-only, unless opened within Adobe's own editing software. Support for importing and converting to and from the PDF format is widely supported by document editing software.
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.
