Thanks @bandages - that gives me some insight into this.
Actually, snapping FK bones to IK bones is really easy with python, see here: https://blender.stackexchange.com/questions/223462/how-to-match-fk-bone-to-ik-bone-via-script
That code will snap a FK bone chain to an IK bone chain. I made a test file using that code, and it works. I’ll post the file, when you open the file, in the text editor will be a script called ‘FK_to_IK’. Running that script will snap the FK bones to the IK bones.
basic_ik_fk_snap_setup.blend (769.9 KB)
Snapping IK to FK is also easy, except for the pole target. In the posted file, in the text editor there is another script called ‘IK_to_FK’ which does the same thing as the other ‘FK_to_IK’ and it works, but the bone roll is off… The pole target for the IK isn’t adjusted to match the FK bones.
In my case, I’ve looked over my code and rigify’s code and adapted my code as needed. I’ve got FK to IK snapping working. And IK to FK is working as well, except for the pole target… that’s where things get messy code wise.
Once I figure out the code I’m currently working with, it would take some work, but it could be turned into an add-on. I’ll keep that in mind as I work on it…
thanks,
Randy