I'm new to Blender, and am trying to teach myself how to rig. I have a simple robot model with two arm bones and an IK bone on the hand to control the arm. The IK bone's Deform box is unchecked. I selected the "forearm" bone, then the IK bone, and selected "Inverse Kinematics." Under bone properties, I have specified that there are two bones in the chain. I think that this should make the entire arm should move (bending between the two bones, with the shoulder remaining fixed) but whenever I hold the IK bone, all I can do is rotate it alone. If I grab the upper arm, I can manipulate the entire arm, with the IK bone staying fixed (unless I pull in the other direction--the arm will come with me.) I must be doing something very simple wrong, but I can't figure out what it is.

The leg is an even bigger problem. I have two leg bones and a foot bone, with an IK bone coming off the heel. I select the foot bone first, then the IK bone, and select "inverse kinematics," which makes the two bones rotate a seemingly random amount.

  • $\begingroup$ Could you add your .blend file using a service like: pasteall.org/blend so that someone could analyze it? $\endgroup$ – stacker May 15 '14 at 20:44

I know you probably know the answer already since this was at May 15th.. But anyway.

The IK should not have any properties. The only ones should have properties with IK's would be the [Lower leg]/[calf] bones and the [lower arm]/[forearm] bones. There are many types of ways to use IK's but you only have them present for the forearm and calf bones. Make sure that they are not parented to the bone that is trying to use its IK. Also under the IK constraint, be sure to have an IK chain length of two. Sometimes you can add the shoulder bone or hips with a three chain but gives odd movements. Also arm IK's also work great with pole bones. Either elbows or knees. I suggest a blender IK rig tutorial.

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