Character animation is key to creating a compelling cartoon. It is the animator's responsibility to create characters that are unique and compelling. A character can be designed brilliantly, but if that character doesn't move or act in an interesting way, the audience will become bored. In 2D animation, the artists must draw each aspect and frame of animation; this requires a great deal of knowledge about human expression and movement.
Facial Expressions
Facial expressions help define many aspects of a character. They can help to show mood, general personality and a character's inner thoughts. If a character receives unexpected bad news, his facial expression might slowly drop from a smile to a frown over a series of frames. If a character becomes enraged by something that is happening, his normal face may slowly begin to become red in color as stress lines appear on his forehead and he begins to scowl. A character experiencing relief may slowly have a smile appear on his face.
Body Language
Body language can also be used to help in character animation. Body language can give the audience an immediate idea of what's going on in a character's mind. A character that is animated with his arms crossed while another character speaks will come across as detached or defensive. You can animate an exasperated character with sudden jerking movements of the limbs and head. The face can turn from side to side looking for something that isn't there to enhance the feeling of exasperation.
A good exercise to increase your body language vocabulary is to observe people at a park. Do quick sketches of the poses people strike as they are talking or moving about. Note what you think the person's general mood is and use this as a reference later in your animation.
Cadence
The speed that your character does actions can have a significant impact on how they are seen by the audience. Hyper characters might twitch their limbs more and finish movements in fewer frames than normal characters. Lazy or sleepy characters will take more frames to accomplish the same basic movements as normal characters.
The speed at which a character moves can also dictate his emotion. Content people tend to move slower and take their time. Angry people may move in quick and sweeping motions. Sad people may move slowly while they are by themselves but then hurry away from groups of people. Take all of this into account when animating your characters.
