Making a knee bend in a desired way in IK setup, is as simple as just changing that bend in edit mode. But what if I want the knee to be able to bend both ways, depending on situation. A switchable behaviour set up by say a driver. Is something like this possible to achieve in blender? Should probably add that I'm not working with a leg setup, just using the knee analogy, to refer to the point between two bones in IK chain.

  • $\begingroup$ Maybe it's not possible with a classic knee IK setup and you have to mix IK on your lower leg (Chain Length 1) with a Damped Track constraint that will track the thigh to a kind of pole target? $\endgroup$ – moonboots Oct 5 '18 at 10:04
  • $\begingroup$ Thanks for your reply! Unfortunately using chain length 1 IK on the lower leg, doesn't seem to keep it grounded when rotating the upper leg with damped track. $\endgroup$ – John Oct 5 '18 at 15:03
  • $\begingroup$ Actually I think I just made it work using as you said damped track, but with chain length of 2. When carefully moving the tracking target bone closer to the knee, the upper leg swaps its bend. Although it's a bit unpredictable when exactly it will change its bend. $\endgroup$ – John Oct 5 '18 at 15:24
  • $\begingroup$ I was not sure about this solution, if you find something satisfying, please post a detailed answer $\endgroup$ – moonboots Oct 5 '18 at 15:31
  • $\begingroup$ I understand. I'm not yet 100% satisfied with this solution though. In the animation I'm doing, when the knee gets completely straight, I need it to continue bending in another direction. However the transition seems a bit jumpy, not too noticeable but still. $\endgroup$ – John Oct 5 '18 at 16:23

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