There is a tendency for animation students to forget the importance of film theory. Animation is of course about movement, so we often look to animations created in the past as our principal way of learning. But the ideas about animation that occupy themselves less with core physical mechanics and the nuances of motion, such as narrative, composition, staging and timing, are first and foremost rooted in the language of film narrative. So if we are to understand the creation of animation not for itself, but for a greater whole anchored in the language of film, then we can look to the entire history of live action film to gain a greater understanding of how to approach various obstacles in CG.
When we refer to secondary characters, we are often just speaking about the characters occupying the background. These are characters that are not directly involved in the performance of the heroes or principal characters in the shot. Background characters fulfill the critical task of making the scene believable. So just to be clear, don't think of a secondary character as someone that is less important to the story than the hero (for example, the hero's ugly twin brother that only shows up once in the film). A secondary character is like an extra or a background character. Their performances are a critical aspect of a shot, and require just as much love from the animator as the principals. In live action film, a great deal of importance is placed on the composition and direction of the extras in the scene. Quite often, when I watch a film for the second time, I will look exclusively at the background characters in a scene as it unfolds, to see how the extras were directed. You can sometimes catch an extra doing something odd or performing in a way that is inconsistent with the scene and the other extras surrounding him. When this happens, if the viewer catches it, the believability of the scene is breached. While this may only be in some small way, depending on the nature of the performer's action and how close to camera they are, the fact of the matter is that background characters must be handled with care, as they can serve to either enforce the story or have a negative impact on it.
There have even been some films where this notion gets turned on its head by the more masterful directors. Take for example a truly brilliant scene in Alfred Hitchcock's Strangers on a Train, where the insane Bruno Anthony (played by Robert Walker) sits with a large crowd who are watching a tennis match. Every extra turns their heads from left to right, left to right, in perfect unison, watching the off camera tennis ball getting hit back and forth over the net. But as the camera pushes in, we notice Bruno sitting right in the middle of the crowd. He does not turn his head, but instead stares menacingly at his co-star who sits across the court. One person, performing out of character from the rest, can draw a huge amount of attention to the viewer. In this case, the character out of synch wasn't an extra, but a main character. Hitchcock used this to create a feeling of ominousness and insanity, revealing to the viewer that Bruno is not like everyone else.
Let's look at another example. Imagine watching a movie about a high school football game. In the fourth quarter, the score is tied and there's three seconds left on the clock. Now imagine that the stands are filled with........no one. Imagine the stadium is empty. No one is watching the game. This would have a dramatic impact on the believability of the scene. No boos, no cheering, no ambient motion filling every shot, no cut-ins to reactions when a goal is scored, or when a pass is missed. The scene would be flat!
Some directors have completely mastered the use of extras or background characters in their movies. I think of Robert Altman films like Nashville, or Stanley Kubrick's epic masterpiece Barry Lyndon, or Laurence of Arabia. These are examples of films with hundreds of extras performing in a way that enforces the narrative but never dominates or overshadows the principal characters unless otherwise intended (as we saw with Hitchcock).
From an animation standpoint, background characters can often provide the animator with an enormous amount of creative freedom. Most often, background characters won’t be as rigidly directed as the principal characters. This means that the animator can experiment in many different ways. Quite often, early motion tests, either for rig development or as a means to understand the way the character moves and expresses itself, will find their way into the backgrounds of a scene. Because so little direction is often put into background performances, animators may go straight ahead in the creation process, animating as loose and creatively as possible. Background animation opens the animator up to the whole gambit of possible actions that character might perform in the scene. Going back to our crowded stadium example, you could animate a little girl eating a hotdog and the wiener pops out the back of the bun and lands on her dress. Or maybe you'll need to animate 10 different ways characters might clap their hands. Whatever the scene might be, background animation can be super detailed, refined, and creative.
There are, however, some limitations both creatively and technically when creating background performances. Some background behaviors may be required to cycle, or conform to the requirements of a massive pipeline (crowd simulations that plug and play different cycling animations). As with live action, when animating background animation, the performance should never be so big as to draw attention to itself and possibly remove focus from the heroes. Nor should the actions be inconsistent with the tone of the scene, nor should the style of the animation diverge from the general style of the project. Often you may not know where or how your background animation will be used, so you can end up sort of animating in the dark. Inevitably, someone will need to customize the performance to the shot for a number of possible reasons. The animations may need to conform to certain frame ranges, or the performance may need to be altered for uneven terrain or camera angles specific to the shot they are placed in. The eyeline of the character may need to be changed, foot contacts, a character's silhouette or orientation to camera, or a “big” action in the animation may be landing in sync with an important moment in the hero’s performance.
You can have a ton of fun creating animation for secondary characters. Keep things loose and creative, and remember that they are there to enforce the narrative qualities of the scene, so they serve a critical importance in the language of film. Guest Blogger Aaron Gilman