Skeletal animation

When the animated object is more general than, for example, a humanoid character, the set of "bones" may not be hierarchical or interconnected, but simply represent a higher-level description of the motion of the part of mesh it is influencing.

The process of rigging is we take that digital sculpture, and we start building the skeleton, the muscles, and we attach the skin to the character, and we also create a set of animation controls, which our animators use to push and pull the body around.This technique constructs a series of bones (which need not correspond to any real-world anatomical feature), sometimes also referred to as rigging in the noun sense.

Skeletal animation is referring to the forward kinematics part of the rig, where a complete set of bone configurations identifies a unique pose.

Each bone in the skeleton is associated with some portion of the character's visual representation (the mesh) in a process called skinning.

Virtual anatomy properties such as weight of limbs, muscle reaction, bone strength, and joint constraints may be added for realistic bouncing, buckling, fracture, and tumbling effects.

Joints or bones (in green) used to pose a hand. In practice, the joints themselves are often hidden and replaced by more user-friendly objects or simply toggled invisible. In this example from the open source project Blender , these "handles" (in blue) have been scaled down to bend the fingers. The joints are still controlling the deformation, but the animator only sees the handles.