An Avar or Animation Variable is a variable
controlling the position of part of an animated object, such
as a character. The character "Woody" in
Pixar's movie Toy Story uses 700 avars (with 100 in the face alone
[1]). Successive sets of Avars control all movement of
the character from frame to frame. In development they are
used to define the junctions of a Stick model. Later they
are incorporated into a full Wire frame model or a model
built of polygons. Finally surfaces are added, requiring a
lengthy process of Rendering to produce the final
scene.
There are several ways of generating the Avar values. Motion capture uses lights or markers on a real person acting out the part, tracked by a video camera. Toy Story uses no motion capture, probably because manual control by a skilled animator can produce effects not easily acted out by a real person.