Does there exists any command line tool that helps you import/export obj/fbx files. I couldn't get the autodesk fbx converter to work. Any decent package preferably CLI tool out there that does the heavy weight lifting or if there's any three.js converters.
For converting various 3D file formats, you can use assimp (https://github.com/assimp/assimp).
A library to import and export various 3d-model-formats including scene-post-processing to generate missing render data.
It also provides a CLI tool (which you have to build yourself).
However, it states that FBX export is still experimental. But give it a try!
EDIT: I just see, there is also a compiled version by now (if you are working on Windows): https://github.com/assimp/assimp/releases/tag/v4.1.0
You have to look for assimp.exe.
Docs on how to use CLI tool should be in doc/AssimpCmdDoc_Html/AssimpCmdDoc.chm, which is, however, a bit outdated.
Basic usage is:
assimp.exe export input.fbx output.obj [additional parameters]
See assimp help and assimp export --help for additional help.