Copy relative positions of empties to bone rotations in a smaller armature I have an armature and a set of empties that line up with each endpoint of a bone by their relative positions, but not by their literal locations or overall scale.



The empties are animated in the way I would like the armature bones to move.



How can I map the relative positions of these empties to the bones' rotations? I'm using Blender 2.79.



(I do NOT want to just match the literal locations of the empties to each other by scaling them down or scaling up the bones, as pictured below.)



UPDATE! Thank you to batFINGER for letting me know about the Track To object constraint. Now I can do this:



(Yes, I did start with the tutorial from Remington Graphics on using a Kinect for motion tracking. He did not mention in his video how to assign the Motion Tracking data to an armature that isn't what he set up in his free .blend file, which is what I set out to do here. While he uses Stretch To constraints, I use Track To and Copy Rotation.)
Rotation constraints.



Going off the image in question, contend this can be done with two copy rotation pose bone constraints.

Add a copy rotation constraint from base pose bone targeting base emtpy. Check the offset property.  Do for corresponding bone - empty pairs down the chain.