Limit Rotation of rigged Arm with IK

Hello everyone still here for asking noob question about rigging, I am try to do some rigging on arms on my model as see in the pic.

I want to limit the rotation of Bone 1 (as well as for hand too), my arms is controlled by the bone on hand (2) and (3) , on bone 1 is applied the current IK bone constraint
Now I would like to apply limitation on the possibility of turn my arm bones but seems I am not able to accomplish that, I did try to play on bone properties as well as adding a limit rotation but seems it not working as I expected and my arm could go behind my model back :slight_smile: How to apply this kind of rotation limitation with IK ? Thank you

In general, bone constraints (like limit rotation) won’t work with IK. At any given moment, it’s either use IK or use bone constraints, not both.

You should look at properties/bone/IK (with “1” selected in pose mode) and consider locking or establishing IK angle limits for those bones.

It doesn’t look like you have a bend built into the bones. Ideally, you should build a slight bend into the bones to indicate to Blender how you want them to bend in the presence of an IK constraint. This is usually sufficient to limit bones, and additional angle limits are often a bad idea (usually, any time they actually do anything, they’re likely to lead to animation twitch.)

Usually, the solution to angle limit problems is, don’t pose it like that. In this case, that means, don’t pose the IK target and/or pole target in a position that leads to positions you don’t want. Many people create pole targets for IK when they would be better off without a pole target; a pole target is optional, and if you don’t want to pose the pole target bone, you shouldn’t be using one.


the pole target kills all kinds of limitations to the bones. The limit rotation ajustments in the IK panel are also disabled when you activate a pole target somewhere in the IK chain. So you have to decide wether you want to limit your bones or use pole targets.
I recently stumbeled over that problem and I’m not sure if it’s a bug or developers intention…


That’s not quite true. That’s true only for the first bone in the chain. For subsequent bones in the chain, you can use both IK limits/locks and a pole target.

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Ah…ok, good to know! Thanks, that might avoid some potential trouble for me :smiley:

Thank you for the awesome explanation and tips, I am really new on blender so everyday learning something new :slight_smile: