title: Is It Possible To Create A Quaternion Twist Solution Which Allows For 360 Degrees Rotation?
body: <p>I have recently been reading about quaternions and was wondering if it is possible to create a system which allows you to create a twist system which doesn't flip at +/-180 and allows for 360 degree twisting?</p>
  
  <p>Every test I've done keeps coming back to calculating an angle between two vectors which always gives you an angle between 0 and 180.</p>
  
  <p>If you're unsure of exactly what I'm looking for then this video from <a href="https://vimeo.com/63911251" rel="nofollow">Jorn-Harald Paulsen</a> should make it clear, I'd like to do it with quaternions but I'm not sure what method he uses.</p>
  
  <p>I've read <a href="http://www.joleanes.com/flippingless.html" rel="nofollow">Felix Joleanes'</a> article on his website about preventing flipping, he has a section dedicated to a twist setup, but it's more like an aim/lookAt constraint and this setup wouldn't work for distributing twist along for multiple joints. It's also depends on using some tricks/hacks with Euler angles which I would rather avoid in favour of quaternions.</p>