https://www.youtube.com/watch?v=UHjkMThH0aE https://www.youtube.com/watch?v=UHjkMThH0aE and the subsequent videos might be more interesting. I remember seeing a

https://www.youtube.com/watch?v=UHjkMThH0aE https://www.youtube.com/watch?v=UHjkMThH0aE and the subsequent videos might be more interesting. I remember seeing a really good video explaining and demonstrating this system a few years ago, but can't find it again unfortunately.