IK Bone moving in wrong direction.

Hey forum!

I seem to be having a problem setting up IK rigging for my character. The fundamentals are there its just when I move the leg it bends upward instead of bending forward. Any ideas how to fix this?

How it looks:

How it should look:

FILE: Character Test.blend (840 KB)

Welcome to BA!

Post the blend file please!

I guess the problem is with the bone setup before the IK target is moved, IK chains must NEVER be dead straight or the solver does not know which way to bend the rig, also you can set IK properties for each bone on the IK chain to stop them rotating in ways you don’t want, so you can lock X and Y and only let the bones in the chain bend in Z, but you do this in the IK Properties, NOT with Limit Rotation Constraints, etc as the IK solver ignores every other form of axis lock, or constraint.

Cheers, Clock.


Looking at your rig for a second time, I think the rig is behaving exactly as it should for the way you have it set up, i.e bending in line with the offset from straight, post the blend file and I will point you in the right direction.


Hmm I am a dummy - you have posted the blend file…

OK so there are several things in your blend file that you need to look at, here are some:

Unapplied Scales on both your Armature and Mesh:

Don’t scale in Object Mode, scale in Edit Mode, or Apply the Scale (CTRL+A => Scale), same goes for rotation as well… :ba:

No “Root” bone, should be between the feet and IK targets/major structural bones should be parented to it.

No connectivity between legs and spine - there should be structural bones here.

Why do you have a “Dick” bone??? :eek:

There are others, but they can wait.

Here is my standard “bow legged” rig:

And blend file: bent_leg.blend (470 KB) - just press Play to watch it - then look at all the bones IK properties, which inherits scale, rotation, etc. What does what in the animation, etc. It’s not the only solution, but it works for me.

Cheers, Clock. :slight_smile:

A dick bone is the cornerstone of any good rig, I thought you’d know better Clock. :smiley:
In addition to what he said, there is a property in IK constraints that allow shifting the pole angle so that even though your bone chain is hazardly placed you can correct it afterwards.


Hmmmmm, I see you in a whole new light now Sir! :stuck_out_tongue:

I wil endeavour to add this bone to all my rigs in future. :eek:

Cheers, Clock.

Haha excuse my dick bone fellas. Thank you for all your help will be putting all this into consideration and get back with you!