Skin
Skin
The skin object is a deformer that has been developed especially for character animation. It takes over the task of deforming the character mesh from the joint objects or any other objects that have a Weight tag assigned. As with all deformers, the skin object must be a child of the mesh it is to deform or it must be on the same hierarchy level within an object group.
Unlike other deformers, the skin object only works with editable polygon objects or, in certain cases as described below, with point objects (that is, objects which contain points, such as splines and FFDs).
If you're using a Subdivision Surface object with your character, the skin object must be a child of the character's mesh or grouped with the mesh inside a null. The null must then be a child of the Subdivision Surface. Otherwise, you can get unexpected results when the mesh and skin object are on the same hierarchy level directly under the Subdivision Surface. This is because the skin object will then be affecting the Subdivision Surface.
With the old bones system in Cinema 4D, the bone objects has to be children of the character's mesh. Now, however, you can place the joints wherever you wish in the scene hierarchy, completely independently of the skin object and character's mesh. This is because the joints themselves are not deformers and they are linked to the mesh via the Weight tag.