There's no event callback / hooking system that lets custom code run before a transform operation enters its modal state (when you drag the mouse to tweak the transform before pressing Esc to cancel or Enter to confirm) Hm... actually, as I'm testing it, the "Depsgraph Update Pre" signal does fire as soon as you select a…
Basically in CS you can create a biped (skeleton) in a couple of clicks with IK controls ready to go. Hi. The closest thing in Blender is Rigify, an add-on that, like others, comes bundled with the Blender installation. It's a humanoid rigging add-on. I think it comes disabled by default, you need to go to your Preferences…