|Al Hirschfeld in life and caricature|
The skill of caricature is to see past unnecessary detail to the underlying shapes of a face. It is the process of analyzing and editing. What is essential to a likeness and what is not?
This same process is at the core of life drawing. Someone looking at a posed model is using knowledge of anatomy, perspective, composition and design to reduce a three dimensional figure to a two dimensional representation. What detail is necessary to communicate the gesture and what can be ignored? An untrained artist can trace a photograph of the same pose and while it may superficially resemble the figure, the lack of underlying knowledge will be obvious. There is no analysis or editing, there is only imitation.
Human movement communicates. From infancy, we develop the skill to read body language and facial expressions in order to understand what is happening in another human mind. Because we do this intuitively, we are not aware of the analysis we are doing. We don't consciously realize that some movements and expressions communicate more than others, the same way that some facial detail defines a person's appearance more in a caricature.
Using live reference without understanding how the body uses weight, balance, momentum and time is useless. Using live reference before knowing what movements communicate and what movements can be ignored leads to a result no better than tracing a photograph and calling it a life drawing.
Analysis and editing are essential. Exaggerating what's left after you have eliminated the unnecessary makes the communication more vivid for an audience. We see people moving every day. Acting is a heightened version of daily movement; it's a way of communicating thoughts and emotions more directly than we see in normal life.
Live action reference can suggest things to a knowledgeable animator; it can help the animator analyze how a movement communicates. But without the underlying knowledge, an animator cannot discriminate between what helps an audience understand and what distracts from understanding.
There is a difference between imitation and communication. Until a student understands this, live action reference is simply a faster way to imitate human movement. If the movement is no more insightful than what we see in life, animating it is unnecessary. What we want is movement that communicates more precisely than real life.