An OBJ file is a standard 3D image format that can be exported and opened by various 3D image editing programs. It contains a three-dimensional object, which includes 3D coordinates, texture maps, polygonal faces, and other object information. OBJ files may also store references to one or more .MTL files that contain surface shading material for the object.
OBJ file open in Microsoft 3D Builder
The OBJ format is considered to be a universal 3D model format since it is widely supported by 3D image editing applications. The format is simple and text-based, which is one reason why many programs use it. However, the simple format structure may also lead to huge OBJ file sizes if they store large and complex 3D objects.
You may encounter an OBJ file in a variety of ways, such as when modifying 3D objects in a video game, creating visual effects for a film, or designing a 3D mockup of a real-life object or building. Since the OBJ 3D format is so widely supported, many users export their models as OBJ files when transferring them from one 3D program to another or when sharing a 3D model with a co-worker.
If you receive an OBJ file you can choose from a large number of free and commercial applications to open it. However, you should select the program based on the context in which the OBJ file will be used. For example, if you are looking to open and modify a 3D object utilized in film special effects and are on a tight budget, you could use the free Blender software.
NOTE: While the OBJ format is one of the most common formats used for storing 3D models, it is only one of many options for saving models. Some other options include .DAE, .STL, .IGS, .FBX, .MAX, .DWG, and .3DS.