Animated Layer Order not working in smart action

[haleycollins]

I am having trouble creating a smart action where I am turning the torso and moving the arms in front of and behind the body as it turns. When I create a layer order animation keyframe in the smart action, it shows up, but the layer won't actually move in the layer panel. I don't have any other layer animation order keyframes so I'm not sure why that could be. I am attaching my rig file, the smart action is called "Chest_L_R"

https://www.dropbox.com/s/6ofjvet653w9k ... .moho?dl=0

Thanks for any help!

[synthsin75]

You're already using animated layer order in another smart action (Head_Turn) for the Rake group layer.
You can only have one smart bone control a group layer's layer sorting. If you need it for the head, you need to do that in a head group.

[Greenlaw]

IMO, instead of using animated layer order for this, It's better to split the arms and duplicate layers, and then animate their visibility states.

For example: create a duplicate or reference layer for an arm group, then place one group layer in front of and one behind the torso. Then use an action to reveal and hide different sections of the arm to make it be in front of, behind, or to appear to wrap around the torso. This can be done by splitting the arms into sections or using masks to hide/reveal sections.

There are many ways to segment the arm (or any limb) at the joint so it appears to bend seamlessly as it wraps around the torso. Here are some common techniques...

For bitmaps, I like to use a vector mask layer that has no antialiasing in it (to prevent an anti-aliasing 'gap' from appearing in the final render.) If you bind the vector mask to follow the joint bend properly, the arm should appear to wrap in front of and behind the torso seamlessly. If you look at the King Julien and Croods animations I did in Moho, this was the setup used. (See my 2017 demo reel for reference.)

For vector art, I like to split the arm curve at the elbow joint and create two shapes instead of one, that is one for the upper arm section and one for the lower arm section. Next, duplicate this layer and knock out the upper arm shape in one layer and the lower arm shape in the other using the Delete Shape tool. Be sure to delete only the shapes and not the points, so you still have the full curve for the arm in both layers. Retaining the full curve allows the arm to bend identically at the joint. You'll also want to add a single point in the 'split' curve so you can pull it over the joint slightly...this prevents an unsightly gap from appearing when you render. You can see examples of this in my Boss Baby footage animated in Moho. (See my 2019 demo reel for reference.)

When you set up the Smart Bone Dial (SBD) to control the arm wrap, make each frame in the action represent different visibility states for the arm sections. I typically make two SBDs, one for the left arm and one for the right arm, and each one controls 4 possible combinations (sometimes 5 if I want one to completely hide the arm.) For example, the SBD for the left arm would control these combinations:



To reduce screen clutter, some animators will use a single SBD to control every possible combination for both arms together. I prefer separate L/R SBDs because it's easier to animate with, but either way works well.

Side note: Many years ago, I would use Stroke Exposure to control a sliding mask for this affect. It was cool in theory but completely unnecessary in practice. It's much easier and just as effective to simply hide and reveal the sections using visibility keys. I'm just mentioning this to show there are many different ways to set up and animate 'wrap' controls, and you'll want to experiment and see which one works best for you. The ones described above are just my usual goto techniques.

Hope this helps.