Double Bind for Layers

Double bind is very useful for having a specific sub-root bone in a layer to control not only the image in the same layer, but also the image one-level higher. Therefore, this method ensures you the connectivity of the joint areas between two body parts when the character is performing.

Given a free-bone character constructed with multiple layers:

The layers are shown as in the illustration.

Notice that the bind statuses for all layers in the rightmost column are Single Bind.

This means that the sub-root bones of these layers only control the image in the same layer. Take the hand layer as an example:

Therefore, when you animate the bones in a layer, only the image in the same layer can be animated, which causes the broken issue.

To solve this issue, you need to:

1. Select the character and click the Composer button on the Toolbar.
   
   
2. Open the Layer Manager in the Composer mode.
   
   
3. Find the desired layer and then click the Double Bind button.
   
   This will ensure that the layer image connected to this sub-root bone can be animated as well.
   
   
4. Press down the Preview button and use the IK or FK methods to view the animation result.
   
5. Even if you use the Motion Key Editor and offset the layer, the layer that is double bound will also be driven by the bone.