Converting file types

Hi, I cannot figure out how to convert a .unity3d file type to a .unity file type. Does anyone know how to? My friend did it, but forgets how he did it.

.unity is the file format for a scene. this filetype can be opened by the unity editor. .unity3d file is the filetype for compiled games and you can open them in the web player or activex. there is not any official conversion tool for this operation. it's possible to extract all resources from .unity3d files but you need to parse it yourself. there is no official documentation about file format structure of unity file formats. the scripts can not be extracted because they will be stored in compiled format in unity3d format. you can disassemble CIL code but nothing more.