Converting a given 3D model (a .obj file) to JSON format
Three js has its own converter now
The converted location in source code
So if you just downloaded three.js you should goto <your threejs root folder >/utils/converters to find the converter.
now in the command lin
cd <your threejs root folder >/utils/converters
obj2three.js <path to your model or .obj file>
Now a JSON file will be created in the folder you are in. You can use this with your JS code. Have . fun