3D rigging or 3D Character Rigging is a process used in the animation of digital characters. It is also known as skeletal rigging in some cases (you’ll see why in a bit). To simply explain it, rigging is the process of creating a digital skeleton so that the character mimics real world (or non-real world) motion that is initiated by skeletons.
The skeleton is made up of a series of digital bones and joints, which is then responsible for translating movement to that portion of the character. That movement is then used in concert with the rest of the skeleton. The animation, obviously, can be as precise or as imprecise as the animator wishes it to be. The more bones a rigger uses, the more poses the animator can use to simulate movements onto the character.
The way each “bone” affects the movement is very complex. In one form of rigging, bones can only affect bones that are below it. So a shoulder will only affect the bones of the arm below it, not anything else. The leg is likewise limited to its own movement. In another form of rigging, the animator can choose which bones affect the movement of the character, and how. For example, instead of the shoulder being the rotating point for the arm, the animator could use the elbow. This second form of rigging is mostly used for the animation of arms and legs.
What is it Used For?
3D Rigging is used primarily for the animation of animated characters in film. For example, movies that are totally animated use 3D rigging to animate the characters. It is also used in films that use CGI.
3D rigging is also used for other purposes. In academic study, for example, it is used to study the movement of bones in the actual human skeleton, as well as in robotics.