Illusion of Life in 3D Character Animation. Part 1

What are the most common mistakes new animators make and why? Could it be that the mistakes come from ignoring the classic rules of animation? Back in 2003 I did a study wishing to confirm just that. Idea was to find what makes good animation and then, via a case study, see if new animators can hit the target – and if not see where they fail and why. Study was in Finnish, title translates to “The Illusion of life in 3D Character Animation” – my final thesis in Multimedia studies. I shall examine this in 2 articles though without the ‘scientific’ style and constant referencing. References are listed at the end.

What is good character animation?

Illusion of Life in 3D Character Animation, poster for the study

Unquestionably we want to see characters come to life. To seem alive a character has to move like a living creature and show self-motivation in it’s actions. Illusion is based on how it reminds us of life and how at the same time it is a caricature – and imitation of life rather than a copy. A copy of life would be difficult and boring to do, and could not be applied to all imaginary characters. Imitation is enough. What is there to imitate, then? Two things: Lifelike motion and acting.

Since acting is, in my opinion, more advanced than making things move ‘right’, and since it would have expanded study scope greatly, I chose to ignore it. But I did expect lifelike motion. To achieve that one needs to study motion.

Discoveries made from studying motion

  • Balance Origin of motion. Each movement is caused by gravity, or other such major force, or is a reaction to it. A move starts by going off balance and ends by again achieving balance. Character has a center of balance and to move about a character has use energy to get that center moving, actually often falling. For example walk is a combination of controlled falls. Fall, catch, fall, catch and so on.
  • Balance. A bipedal character is in balance when you can draw straight line from base of the neck to A) the leg that has weight or B) to a direct line crossing the two ankles.
  • Tilt & Twist. Gravity gave the need for a rigid supporting skeleton and we move it with muscles. But muscles are expensive to both build and use, so creatures with rigid spine(vertebrate) have evolved a way to move by tilting and twisting. In fact all vertebrate moves are rotation of some sort and every body part involved in creating a motion rotates on three(3) axis.

Tilt and Twist
Look at bipedal walk. Tilt and twist of the hips gets a leg up and going and gives reach to the motion. So also moves the point of balance. Rotations of upper body help to compensate for this. Other vetebrate creatures like lizards have short legs but compensate this with a very flexible spine. Understanding movement and then by training futher bare skeletons can tell you how a creature would move in life.

Principles of the Illusion of Life

Animation professionals, back in the first golden age of animation, studied things like the above and developed principles to achieve Illusion of Life. They still apply. For purposes of my study I’ve chosen 9 about lifelike motion and ignored others that concern storytelling(framing and more) or acting. The explanations are my variations of what you can find elsewhere on the net or in books.

  1. Tilt & Twist As explained before vertebrate movement is all about rotations.
  2. Dynamic balance is having characters mass, inertia and energy in balance. Body parts work together for balance.
  3. Dynamics is making note of the laws conserning mass and energy and applying them to animation so it looks like things have weight. Often dynamics is called acceleration and deceleration.
  4. Follow Through and Overlapping Action means that in nature not all parts of a character get to speed or stop at the same time.
  5. Squash and stretch concern shape changes – all living creatures shapes change in movement in many parts of the body and even as a whole, too, in extreme motions.
  6. Arcs: natural movement goes in arcs. It has to do with rotational joints and gravity. See no 1.
  7. Natural faults and variance, even chaos. This is the spice of life – imperfections in all things.
  8. Anticipation is simply anticipating and action with a counter-action. All natural motions have anticipation.
  9. Subconscious action is what everybody does without noticing, like shifting weight when standing. It is part personality, part chaos that is life and part the fact that living things just get stiff without motion.

All the above principles incorporate timing. Timing (what moves when in relation to what else) creates illusion of weight and more. Think of it as the tool to do the principles with.

As you can see, the principles above come from the real world. Yet using principles with our often unreal worlds and characters gives them the Illusion of Life. It’s the illusion, the touch of familiar we are after, not The Real. Heck, you can have Lifelike Adventures of Mr. Garden Hose by applying these right. And they don’t have to applied exactly like in real life, rather used for good effect. Animation can (and should) go beyond the ‘real’.

I claim using the principles does create lifelike motion and that they are one requirement for good animation. Rest is created with visual storytelling choises and acting.

Do you agree the principles still apply? Have you kept the classic learnings in mind when animating, or do you just trust yourself to get it right, naturally?

Tune in later for part 2 where we examine an animation with the principles in mind.

References used(back in 2003)

Leave a Reply

Your email address will not be published. Required fields are marked *