I've created a little demo for this technology.  It took me just a few hours to make it:
https://hackaday.io/project/172309-3d-printed-joystick
There seem to be many followers of this project, however no one has actively took an interest by building anything.  All it takes is a $5 USB cam and some cheap fiber guys...  Unless YOU create sensors, this project is not going anywhere !!!  What happened?  Is it too complicated or there is a boundary to entry?  I think it's simpler than learning how to solder and program MCUs.  Let me know what's up by sending me a PM  or email: toandrey (at) yahoo (dot) com    I am lost here.