How to work with Auto-attachment feature?

I should write up a blog on this one sometime...  here is my view of the world. I simplify some issues to get the basic concepts across.

There are layers and meshes. Making a layer independent causes a new mesh to be started where all child layers are merged onto that mesh, until a new layer is marked as independent and a new mesh is started all over again.

I think of a mesh like a sheet of rubber. You can layer artwork onto the mesh, but when you start warping the mesh, all of the artwork on that mesh warps with it. The layers are drawn on top to bottom on the screen, so the order of layers affects what appears in front of what.

Also, there is a yellow outline on a mesh. That should hug the outline of the artwork. Its like scissors cutting out around the artwork. If cut out correctly, the puppet will warp nicer. E.g arms can bend nicer. If not cut out correctly,  the arms are still connected firmly to the body (there is rubber sheet still between the arms and the body) so moving the arms moves the body. Not good. So its critical for good puppet behavior to make sure CH works out the contour of meshes correctly.

This also means you cannot have disconnected (non-overlapping) artwork on the same mesh. When you try to cut it out, some will fall on the floor! At that stage CH gives up and does not cut out the artwork at all for that mesh (so the yellow mesh is a big sheet of rubber - not what you want).

Child meshes need to attach to their parent mesh. The “attach to” setting can be hinge which is like putting a pin through both layers - the child mesh will cleanly rotate at the connection point. Otherwise you can use “weld” which is like putting a dab of glue at the connection point - the child layer will try not to rotate at that point - it will try to stay aligned with the parent mesh when it moves. That is, if the body leans to the left, the arm will lean with it.

Hinge might be a nice way to attach a glass of water to a hand for example, to keep the water in the cup level. Hing might also be suitable at the shoulder when the arm connects to the body, so the arm has more freedom of movement. If not, then I throw lots of sticks on the body to stop the arm warping it too much.

Start a new child mesh when you want the child artwork to not affect the parent. E.g. I generally don’t want the mouth of a puppet to affect the shape of the head, so that is a good candidate for independence. Eyes the same - blinking eyes I generally don’t want to distort the face. See https://extra-ordinary.tv/2018/04/21/debugging-character-animator-eyess/  for more discussion on eyes.

You end up with lots of independent layers sometimes, but don’t mistake this with putting independence everywhere! It should be a very deliberate decision. Too much independence can make it hard to connect meshes together, causing floating effects. Each time a new independent mesh is started should be for a considered reason. The child artwork wants to follow the position of the parent, but not warp the parent. Child meshes with a dragger also will not move the parent mesh, so you can limit the scope of a dragger. E.g. A dragger on an arm that is independent will never move the body no matter how hard you stretch it. A dragger on a arm that is a part of the body mesh can move the body as well.

Sticks I generally put on the root layer of a mesh, so I can find them easily. You can nest them on child layers, but I generally don’t. That is just me. That means I think carefully about independence and meshes first. Then I start thinking about sticks and pins etc. Sticks, back to the sheet of rubber analogy, is like putting toothpicks on the rubber sheet. That part of rubber sheet won’t flex any more (as easily). So I put sticks in arms and legs where bones would be, to encourage more natural looking flexing at joints.

I also often put sticks along the jaw line of a puppet if the head is not independent to the body to encourage the neck to flex instead of the shape of the head.

If a head is independent it will swivel without moving the body. If dependent I generally like to have some neck between the head and body so the neck can flex instead of the body or head shapes. So if you want the web cam to move the head and affect the body as well, its easier if the head is NOT independent.

(There are tricks which I will ignore here... okay, cannot resist, you can put a fake head on the body as well and have two face behaviors so the web cam moves the body as well. Rarely done, but can be useful.)

There is an advanced problem. If you want flowing hair behind the body, the head in front of the body, and the hair attached to the head, the ONLY way I know how to achieve this is for the head NOT to be independent. Its a pain. So deciding if you need rear hair behind the body is an important decision early on.

But child meshes always need to attach to a parent. They move with it. If they are not attached, they float away.

- So eyes attach to the face. That is easy. They are drawn in front of the face anyway.

- The body I often draw a long neck that goes up behind the head. That gives the head something to attach to. You cannot have the neck stop at the edge of the head and still have the head independent.

- Arms also overlap the body at the shoulder.

These overlap points becomes the attach point of where the child mesh should attack to the parent. You drag the origin handle of the child mesh over the parent mesh (the parent mesh goes green at that point). When the parent mesh then moves (e.g. the body mesh), the child will follow (e.g. the arms).

You can use pins to fix a mesh to its parent mesh. I generally only do this for the feet of the puppet. But it fixes that point relative to the parent mesh. If your legs are independent and a child of the body mesh, it will fix them relative to the body (not the background of the scene). As a result I typically do not make legs independent if I want to pin the feet to the background of the scene. I rarely use pins for anything else.

I have not talked about profiles here. Too much for one post! But hopefully the above gets you now the beginnings of enlightenment!

Hi there,

I understand your concern. You may use the auto attachment feature for attaching the independent groups.

Check out these two articles: https://helpx.adobe.com/in/adobe-character-animator/using/prepare-artwork.html#subpuppet_attachpoint

1. Prepare artwork in Adobe Character Animator
2. Edit and modify puppet structure

If there is something you need to discuss specifically, please share a screenshot of what happens on your screen so that we can take a look.

We're here to help.

Thanks,

Shivangi