A software I use for animation (Moho) has a new feature called "Vitruvian bones". You can have multiple skeletons inside a skeleton that you can then switch with corresponding graphics. See paragraph "Vitruvian bones": https://moho.lostmarble.com/pages/features Example on usage: Let's say I have a character with a rigged head. If the character would turn head, from facing left to facing the camera, I could just switch the base bone set and graphics would follow. Now the character would have an alternate head graphic, rigged differently that would fit that angle. Another example is that when an arm is animated from side perspective and the character rotates arm facing the camera. Same rig no longer applies so one could just switch the arm "sub"-rig. So basically the feature is: rigs inside rigs, each rig rigged to different graphics.