Pointing an IK controlled rig at an object moving along a path?

Hi and Welcome!

I wonder if anyone can help me with an issue I’ve had.

I have a robot arm model, which I have rigged and set up so it has an IK handle and constraints set up, so that when I drag the end of the arm that has a welding tip, the whole of the arm follows the movement quite nicely.

What I would like to do however, is to have it point or “weld” along a 3dimensional path, while keeping the IK constraints.

Only thing I managed to do so far was to have the single bone (the ik control) point at the path, while ignoring all the IK constraints…

In the attached file, I created a 3 bone arm and added an ik constraint to the last bone in the arm, then I added a 4th bone at the end of the 3rd bone, that’s the ik controller and set the constraint to use that bone as the controller. I then added a bezier curve and an empty at the beginning of the path, parented the empty to the path and choose the ‘follow path’ option from the pop up menu. Then I added a copy location constraint to the controller bone and set the empty as the target for that constraint. When you press alt-a, the empty will follow the path and the controller bone with copy the location of the empty, moving the arm in the process…



Arm.blend (326 KB)

Awesome! Thanks!

I was beginning to think that this is impossible!

Thanks for your help!

I followed these simple steps you provided to the letter, even in the same file you provided - everything seemed to be set up exactly as you have set up, and it still wouldnt move…

What I had to finally do to make it work was to uncheck the “connected” option for the ik controller bone. Wouldn’t have thought that up in a million years.

Really gratefull for the help.