I have downloaded different puppets designed in Illustrator, and I have noticed some differences with how the layers are used with the files.
1. Does the arrangement/order of layers in the Layers Panel matter, or is it just an issue of making sure that they are named properly?
2. I have noticed some files include a "Head" Layer ,while other files have a "Face" Layer. What are the naming requirements for Layers that should be included in a file to create basic functionality? Are the following correct:
Hair (guessing this is optional?)
Nose (guessing this is optional?)
All the different mouth Sub Layers, though I am assuming you can design and use just the ones you like?
3. Does it make a difference if I have a Layer and many objects on that layer, and possibly artwork on sublayers and I choose to group it or not? Does this have any effect on how CA operates?
1. The nesting of layers is very important. Children often are "attached to" the parent, so if they are not under the parent layer they may not be recognized. E.g. Eyes must be inside Head - some behaviors look for Head first, then look for eyes, eyebrows etc.
2. CH automatically tags layers for you based on the name. You can do it manually (in the "Tags" section of the properties panel). So your can call layers anything you like ... but it creates more work for you. So the recommendation is to use the tag names as layer names (like "Head"). Behaviors don't look at layer names - they look for layers with tags on them (where tags are added automatically at times based on the layer name). You are correct - there is no behavior that looks for a tag of Hair, so the layer Hair is just for you as the creator to group things logically. I would also expect to look in that layer for "dangle handles" to make the hair bounce around. So logical naming is helpful, but not always essential.
3. The layer structure is very important to CH. For example, if you want hair to bounce and move a bit in front of the face, you get into topics like "independence". You might rename "Hair" to "+Hair" which adds an independence flag on the Hair layer automatically (you can click the crown and do it by hand, but more work again!). You can then add "dangles" to the tips of the hair to make them bounce. If the hair was not in a separate layer, the face etc near the dangle would also move. So layers are important when you want parts of the puppet to move without moving other parts of the artwork. They are also important when you want to swap/replace artwork. For example, the mouth you draw a series of mouth positions for different sounds. Ch can then switch between your different artwork. The "Visemes" like vowel sounds, "F", "M", etc (see tags again) must appear under a Mouth tagged layer.
So understanding layers is important. Understanding "independence" is also important.
Thanks so much for your reply.
1. The problem I have had was if I keep the eyes within the head Layer they need to be arranged so they are at the very top of the sublayers (not sure if this is what they are called?)within head, otherwise, the artwork for the head/face will cover it. So I am assuming that if I need to keep the eyes inside the Head Layer it is ok to move them to the top of the stacking order of the Head group? If so, I would need to do the same with eyebrows within the Head Layer, etc.
2. Since there is no behavior for a tag of Hair, can I place a Hair layer anywhere I like?
1. Exactly - the order of layers controls what is in front of what. So yes, move the eyes to the top is fine and normal. Just keep under the same parent. Behaviors do not care about the order of children etc (err, 99.9% of the time). Eventually you might hit an annoying advanced cases where "oh, I want in front of that and behind that but the parent layers don't allow that". Things to look forward to! 😉
2. I would do some tutorials on independence etc. If you want hair to be "independent", which I often do so it can bounce around etc, then it has to be "attached" to a parent layer so it moves with it. Normally Hair will be inside Head so the hair will follow the head. I might create a "Hair Fringe" layer in front, make it independent, add some dangles so it bounces around, then change the "origin marker" of the fringe layer to control where on the head it attaches to. A common mistake is to go wild on independent layers. Don't! Add it whenever you want something to move independent to the other artwork. E.g. hair wants to move separate to the face (if long hair or a fringe). But the face skin artwork rarely would be independent - it should be part of the Head.
(deep breath). Why? Because Ch has the concept of "meshes". When you mark a layer as independent, it starts a new mesh. Think of it like a new sheet of paper or thin rubber you draw on. You can stretch that sheet as needed, and it will only affect the artwork drawn on that layer. But you want to attach it with a pin ("hinge attachment") or staple ("weld attachement") which will control how it moves relative to its parent. Your fringe should be attached at the middle/top of the fringe artwork, so it moves with the head.
So there is a clear tree of nested layers - very important for behaviors. There is ALSO a tree of meshes. Children meshes attach to parent meshes. If the Face skin artwork, for example, was independent, you can end up with the "Head" layer with no artwork in its mesh (if all children are independent). That means there is nothing for the children to attach to! So Head generally has the face skin layer not independent, then eyes etc can attach to it.
When you click on a layer, you will see a yellow outline. That is the mesh outline for all artwork in that mesh.
But go watch a video - probably will explain it better.