Segmented arms that work like an actual puppet (w/ examples)?

Report · Jun 29, 2020

So what I'm trying to do is create a puppet in Character Animator whose limbs move as if they're attached by those paper fastener pins (below)

As far as I am aware, I can't use Arm IK because that always adds an elbow, which I don't want. What I'm kind of after is this effect shown in the two images below (if you know what the source material is then I'm very sorry);

(Sorry for the bad quality, I really had to go digging.) As you can see, the above character's lower arms pivot around the elbow point, and the upper arms pivot around the shoulder point, if that makes sense.

I literally don't know if this is possible in Character Animator either, although i did manage to find something close around the 6:30 mark of the 'Adobe Character Animator: 40 Secrets' video, in which he used transform behavious on segmented arm layers to create a similar effect:

As great as this is, it seems that it isn't possible to have the lower arm layer over the top of the uper arm, as the lower arm cannot connect to the upper arm if it's above it in the layer hierarchy.

Gonna be honest, I have no idea where to start, so any guidance would be amazing and help me greatly. If you need any more info from me I'd happily provide. Thanks!

Report · Jun 29, 2020

There is a trick to it and restrictions. To get the layers correct is not that hard actually. To have the lower arm over the top of the upper arm you just move that layer higher:

Body

. +Arm

. . +Lower Arm

. . . +Hand

. . . . Hand artwork

. . . Lower arm artwork

. . Upper arm artwork

The hand is then in front of the lower arm which is in front of the upper arm. (You then use "Attach To" of type "Hinge" not "Weld" to get the pin effect.)

The problem is when you come to draggers. If the arm is independent to the body, you will need a dragger near the elbow of the upper arm, and another dragger at the wrist (at the end of the lower arm segment). Without this, dragging at the wrist will not move the upper arm. This is because nested independent layers will not move the parent. So you have to record the elbow drag and the wrist drag with this puppet. It works, but is more work during recordings. (If the Arm can be dependent you avoid the problem - but as soon as you have two independent nesting levels the problem occurs - each level needs a dragger.)

Does that answer the question?

Report · Jun 29, 2020

I did not say explicitly sorry, but "attach to" is based on nesting, not ordering. "In front of" is based on ordering". So you just need to get it ordered right.

There are cases that *are* impossible. For example, you cannot have a head in front of the body and neck (attached to it), but the rear hair goes behind the body. You cannot do both the nesting and the layer ordering at the same time in that case. Luckily your example with the arms can be done.

Report · Oct 11, 2021

Hello Alank. I've been trying to follow your recommendations here to do a pin-joint-type puppet. However, although I've nested the parts of the arm, used Attached to, and used Hinge as you suggested, the arm segments don't drag each other properly. They just pivot at their origin without dragging anything. Could you PLEASE have a look at where I might have detoured from your suggestion?

Report · Oct 11, 2021

At work at the moment, but the origins when they overlap the parent artwork should turn green to indicate attachment. Not sure why they are not green on your screenshots. Are you able to "Export Puppet" from the menu, share that file via Google Drive or Dropbox or similar? It shares the artwork and rigging hierarchy. On the surface what you are doing makes sense, but obviously something is going wrong. If you are allowed to share the puppet, it can help diagnose quicker. (If you share on the forums someone might jump on before I can after work, otherwise feel free to direct message me.) I think you are 90% of the way there.

Report · Oct 12, 2021

Thank you for sharing the puppet (via DM). I can see a few problems (easily fixed).

If you look at the Attach To settings in the properties, the drop down says the layer above or "Auto". I have never fully understood this setting to be honest, but set it to Auto and then the Left Arm can be attached to the parent mesh correctly.

Repeat for all the independent layers - set them all to Auto. (Upgrading old puppets to newer versions of CH defaulted this to the layer name I think.)
Never have an independent group where all the children are independent. There needs to be at least some artwork in the layer for children to attach to. In your case, "Left Arm" and "L Upper Arm" are both independent, but "Left Arm" only has the one child of "L Upper Arm". So don't make "L Upper Arm" independent. Turn that off.

After those changes on the left arm, things seemed to work much better compared to the right arm.

Report · Oct 12, 2021

That got it fixed!!!! THANKS A LOT Alank. BTW, I didn't know about the need to have at least one non-independent children layer. Now I know, hehe.

Report · Jan 27, 2023

Hi - I want to do exactly as you - BUT getting knowhere how did you 'connect' the forearm to the upper arm at the elbow? There is a new leader/follower behaviour in the latest version - was wondering about thet?