Instead of making a way to create general springy shapes, another interesting direction is to make a way to create springy characters that walk or fly or hop or crawl or slither.
And one thing that those characters usually have in common is that their limbs don’t change length. Arms, legs, necks, torsos — every part of a skeleton can all be quite flexible in how they bend, but the limbs of your skeleton don’t usually grow or shrink when you move.
Unless of course you are Reed Richards, in which case I am absolutely thrilled and honored that you are reading this. Email me — we’ll have lunch. Bring Susan.
Anyway, it turns out that this “limitation” — limbs not growing or shrinking in length — is really great for puppeteering, since the limbs of such skeletons move more like actual arms and legs.