Proprietary 3D application files
Unity can also import, through conversion: Max, Maya, Blender, Cinema4D, Modo, Lightwave & Cheetah3D files, e.g. .MAX, .MB, .MA etc.
Advantages:
- Quick iteration process (save the source file and Unity reimports)
- Simple initially
Disadvantages:
- A licensed copy of that software must be installed on all machines using the Unity project
- Files can become bloated with unnecessary data
- Big files can slow Unity updates
- Less validation, so it is harder to troubleshoot problems