Line of Action Principle. How to improve your character’s posture.

Line of Action is both an animation and drawing principle. It’s a crucial knowledege that all character artists must master, whether you are conceptualizing a human or animal character, for illustration or animation purposes, in 2D or 3D medium. A powerful and clean line of action will always make your character look more alive.

Line of action is the key for adding attitude in the character’s posture or, dynamism in its movement. It’s the touch that creates that feeling of a smooth visual flow.

What is Line of Action

One of my favorite animation books is Cartoon Animation by Preston Blair (originally published in 1944). It’s an oldie but, good advice never goes out of style. In fact, I find this book very inspiring and well-written, it covers all the fundamentals of traditional character animation. Then, let’s not forget that Preston Blair was a veteran with Walt Disney and Metro Golden-Mayer studios. So, according to Preston Blair here’s a definition for the line of action.

An imaginary line extending through the main action of the figure is the line of action. Plan your figure and its details to accentuate this line. By doing so, you will strengthen the dramatic effect. The first to draw when constructing a figure is the line of action. – Preston Blair (character animator, author)

Line of Action (literally is not a line, usually it’s a curve) represents a visual guideline for charcater posing:

• It gives clarity in any character’s posture.
• It gives the feeling of flow, rhythm, and yet simplicity within any character’s posture.
• It’s a visualization of the entire motion sequence, both in time and space.
• It trains the artist’s brain to simply “see” and to “understand” the motion itself, without any other distractions.

Now, lets start and breakdown some of the key points that you can take away and you can really rock in your character posing. I’ll do so by sharing some of real life references.

Line of action as a body posture

Body posture refers to the positioning of a character’s body, it can be a standing or a sitting posture. It simply means the way the character (human) holds or carries their body. A fact to always remember is that, at the core of a posture is the back (spinal) alignment or, curvature.

When generally defining a body posture, there are two terms in doing so.

• Good posture: ability to get in and out of any position.
• Poor posture: physical stress and stiffness of the spine.

Line of action as a body language signal

Think of your character as a real human (in terms of human behavior). Our body naturally reveals how we feel and what our mind is thinking. It gives visual hints about personality characteristics, for example whether a person is confident, open, or submissive.

Character’s posture becomes now an important indicator of its personality or, the state of mind. When trying to read a body language, there are only 2 key postures.

• Open posture indicates: friendliness, openness, and willingness.
• Closed posture indicates: hostility, unfriendliness, and anxiety.

Line of action as a motion sequence

As I’ve said earlier, line of action also defines the overall character’s motion in time and space. Now, the line of action becomes the key in capturing the “feeling” of both, balance and rhythm. Just think about dancers and athletes, how they appear to perform so smooth, confident and elegant?

Here are the two elements to consider in any motion sequence.

• Visualizes the entire motion sequence in terms of line of action, each key pose has its own line of action.
• Create contrast in terms of momentum and speed by reversing the line of action (spine curvature).

Link between character’s posture and movement

When you draw or animate a character, you must analyze the character’s posture as in real life situation. You want to create a believable character regardless of the visual style, how cartoon or realistic it may look. The design of the character is not a limitation but an advantage for creative animation.

Always remember, there’s a natural link between posture – movement. The body must respond to both physical stress (interacting with physical objects) and to emotional stress (the way we think and feel).

A clear and strong line of action will always tell something to your audience, it conveys both the action and the emotion.

Think at the the line of action such as a motion analysis of the character, just as in sports where there’s the motion analyses of the athletes’ performance.

When you first learn character animation or character concept, is not the big things that makes the difference, are the little things. It’s not the design of the character the makes it look alive (that’s just a tiny part of the package) it’s how the character moves in a way that it does support the design and the story.

So maximize your character posing through the use of line of action.

• every posture has its own line of action.
• every motion sequence is defined by key posses with clear line of action.
• accentuated it more in body mechanics such as sports actions.
• exaggerated it for a cartoon style but in a way that still looks believable.

Practicing motion study sketching is the best method for training the brain to see ONLY the line of action. Here’s how I do it – Motion Study of Ballet Dance, 50+ sketches

Related articles

Check out my other animation and drawing principles.

• Squash and Stretch Principle, how to add weight and flexibility.
• Stickman drawing for animators, how to sketch a complex motion by using a simplified way of visualization.