During skinning, you bind a model’s deformable objects to a skeleton. After skinning, the model is called the character’s skin, and the deformable objects are called skin objects.
A deformable object is any object whose structure is defined by NURBS control vertices (CVs), polygonal vertices, or lattice points. NURBS curves, NURBS surfaces, polygonal surfaces (meshes), and lattice deformers are all deformable objects. A character’s model can consist of one deformable object (for example, a large polygonal surface) or of groups of deformable objects (for example, groups of NURBS surfaces).
Typically, a character’s model consists of deformable objects (typically NURBS surfaces, polygonal surfaces, or both) organized in hierarchical groups. The organization reflects the structure of the character’s appearance, and should be based on how the character will be animated. For example, a NURBS model could consist of groups of NURBS surfaces that make up the character’s feet, legs, torso, arms, hands, neck, and head.