Skeleton Layer
From Synfig Studio :: Documentation
Contents
About Skeleton Layers
The Skeleton Layer is to attempt to emulate the skeleton of a vertebrate animal. This feature is still at experimental stage.
Parameters of Skeleton Layers
The parameters of the skeleton layers are:
| Name | Value | Type |
 Z Depth
|
0.000000 | real |
 Name
|
skeleton | string |
 Bones
|
list (Satic List) | list |
Start by adding a Skeleton layer
- Bones names are automatically created. Bones can't be deleted from canvas. You can unreference them in a skeleton layer but they will still available in canvas.
- You only can add more bone by right click on the bones list and selecting "Insert Item Smart". Once added you can modify it and use in other places.
- Bones has two sets of parameters (you can expand it to see them). The default handles bones parameters are the used for make the influence on points. The other set is called the setup values. You can toggle from one set of handles to the other by pressing Alt7 (setup)
- Bones has two kind of scales: normal (for the bone itself) and recursive for the children of the bone. The recursive scales the bone and passes down to the children the same scale value, that is recursively passed down. You can toggle recursive by Alt8.
- Also Alt9 changes between setup->normal->recursive->setup by consecutive key pressings.
- All parameters are animatable but I strongly recommend to only animate the normal parameters for the first time. So the setup values has to be modified in non animation mode.
- You can also animate parent bone. See example.
- Once you have created your skeleton you can forget even deactivate the skeleton layer.
The bones are available everywhere even if the skeleton layer doesn't exists.
Now let's go with the points
- A vector or a spline point can be converted to Bone Influence type. Once you convert it two parameters are shown: Bone Weight Pair list and Link. Link is the original value of the point and Bone Weight Pair List
- The first time a Vertex or Spline Point is converted to a Bone Influence type it would create a bone for that Bone Weight Pair list. Unfortunately this makes the number of bones grow a lot and possibly many of them are useless.
- Once you have it converted to Bone Influence you can add more bones weight pairs to the bone weight pair list as like in any list (Insert Item smart). Later you can modify the bone that is affecting that vertex or spline point. To select a new bone in the parent parameter or the bone parameter of the bone weight pair, just click on the value column of the parameter. A drop down menu with all the existing bones will be offered. Each bone on the list affects weighted by the weight value, so you can make one vertex to be more influenced by a bone than other. If only one bone is in the list, it acts as 100% regardless the weight value.
- Repeat the convert of each vertex and associate it to each bone of the skeleton. Possibly it is better to have a small skeleton (only the root one) and use the convert to bone influence to add more bones when needed.
- Notice that the bone setup position is used to grab the vertex/spline point setup position so each later modification of the non setup value of the bones are relative to that initial position of the vertex, relative to the setup position.
- Of course, you can animate the vertex position along the time and it would be the relative position to the bone setup position. This helps to fix gaps when bone transforms the vertexes in a non desirable way.
