When character rig is generated, these prototype objects are used to create point and box controllers which you can use to animate the character, and also for creating rigid bodies which are necessary for making character movement physically accurate.
To rig a character, you need to add a set of prototype objects to every joint of the character skeleton.
Prototype objects are created in sets. Each set include:
Proto Rigid Body (1)
The main element of the set. Rigid body is attached to the joint (or several joints), while every other prototype is attached to the rigid body itself.
When rig is generated, this object is used for creating a rigid body.
Proto Box Controller (2)
The secondary element that encompasses the joint(s)
When rig is generated, this object is used for creating a box controller.
Proto Point Controllers
- Main point controller (3) is placed at the foundation of the main joint. Prototypes for Point Controller Edges connect it to two more point controllers
- Main direction (4) point controller, placed at the point where the main joint connects with the child joint. Its position is determined by the child joint
- Additional point controller (5). Its position can be set manually using the Additional point in Axis group of parameters
These three elements are used for creating point controllers when rig is generated.
Created prototypes can be selected in the Viewport window. Selecting an element in the Viewport will also select it in the Outliner window, where you can adjust its parameters. You can also use Manipulators to adjust the positions abd sizes of the prototype elements; this is not required, but can be useful in some cases.