[craigseeman]

I first saw this effect in https://youtu.be/XEvSTQKO7i4 and always wondered how it was done.

[sdca]

Here's another one

https://youtu.be/tt7gP_IW-1w

And another that mimics the effect

https://youtu.be/FQlhQ-GrzLk

And another that appears to be a mixture of both

https://youtu.be/b4Bj7Zb-YD4

[dsnuh]

Another... https://vimeo.com/3139412