How to make a advanced torso RIG with I'm learning rigging and most of the rig systems I found pretty easy to reproduce by watching videos and demos. I understand local\global\parent coordinates even creating complex bone based facial rigs, but...

I found realy dificult to create a more advanced rig for a torso.
something like that: https://youtu.be/im5XhbpGXjw
and even do not have ways to think how to describe this kind of rig.

how this hinge and pivot slide works?

Please, don't tell me to use the rigfy addon or blenrig, this is not my goal.
I'm trying to learn how does this stuff work, think will be usefull in future.
That looks the Sintel rig from Blender Foundation Open Movie Durian Project  Sintel.



It is open content freely available to anyone, you can use it study it, modify it and redistribute it as you see fit, along with all assets and production files from the movie.

You can access it by subscribing to the Blender Cloud just like any of the content from all other Blender Foundation Open Projects which will cost you a small symbolic monthly fee.

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