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Salutations,

I am currently trying to make a rig for a project involving 2D planes to create some kind of equivalent of DragonBones in Blender (I'm working on Linux and DragonBones isn't available there plus I thought this'd be a good way to learn rigging). I am using inverse kinematics and managed to use the "Inverse Kinematics" tab to have my bones only rotate around the x-axis. It worked quite well but on certain angles, the bones would bend the wrong way. I decided to add a pole target to fix this and it kinda does but apparently using a pole target nullifies the effect of the "Inverse Kinematics" tab and now I have my bones rotating in ways that I don't want them to.

Does anyone know how I could have both a pole target (or any way that wouldn't make the bones suddenly bend the other way) AND restrict the rotation around the x-axis ?

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  • $\begingroup$ could you please share the bones with the problem? blend-exchange.giantcowfilms.com $\endgroup$
    – moonboots
    Commented Oct 29, 2018 at 10:34
  • $\begingroup$ <img src="https://blend-exchange.giantcowfilms.com/embedImage.png?bid=5458" /> There you go $\endgroup$
    – AnthoJack
    Commented Oct 29, 2018 at 10:38
  • $\begingroup$ your armature seems ok, actually you could correct all these bad twists with the pole target (change its position in Pose mode when you see that your leg is twisting). Could you do it with IK limits ? I'm going to dig that... $\endgroup$
    – moonboots
    Commented Oct 29, 2018 at 11:17
  • $\begingroup$ The solution, in this case, is to not use a pole target; the only reason for a pole target to exist here would be to rotate your thigh bone in ways not allowed by your IK limits. Given your file's IK limits and existing bend, there is only one (or no) solution for the IK chain. If it was bending the wrong way without a pole target, then you need to either change your angle limits to accommodate the way that you want it to bend, and/or you need to change the direction of your bend, by rotating your calf bone in its X axis in pose mode. $\endgroup$
    – Nathan
    Commented May 28, 2022 at 19:49

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Maybe I'm wrong and someone will find a solution with the IK limits but it looks like you can't prevent the knee twisting this way.

You need to use your Pole Target bone to fix the problem, and anyway the Pole Target is here for that.

So, in Pose mode when you see that the leg rotation make your knee twist in the bad direction, just move the Pole Target and give it a Keyframe so that the knee comes back to the right bending.

enter image description here

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  • $\begingroup$ Inverse kinematics with pole target works fine once I've deleted the Inverse kinematics tab constraints but I'll still leave this subject open in case somebody finds a way to lock the rotation even with a pole target $\endgroup$
    – AnthoJack
    Commented Oct 30, 2018 at 9:44
  • $\begingroup$ IK works fine once you've deleted the IK tab constraints? Sorry I don't know what you mean. $\endgroup$
    – moonboots
    Commented Oct 30, 2018 at 10:09
  • $\begingroup$ When I had the IK tab constraints set, moving my IK bone made my parent bones move in strange ways. Deleting it solved it $\endgroup$
    – AnthoJack
    Commented Nov 2, 2018 at 7:58

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