The principles of animation

I got a chance to look at the 12 basic principles of animation. These points are followed by many animators and were set in the book 'the illusion of life - Disney animation'. This book was published in 1981 and written by Ollie Johnston and frank Thomas. Despite it being dated it applies timeless points to make animated characters appear real and fluid in their movements.
1. Squash and Stretch
This is considered the most important principle as when movement occurs, things do get stretched, what it also means is that things also get squashed in reaction to the stretching. The idea is that it gives a sense of weight to the asset. If a ball was to contract as it impacted the ground, it would need to stretch width-wise as the lower part would be squashed. I think of it as though if the item is pressed in then it would need to push out to react. It cannot just disappear.
2. Anticipation
This one is in the name, you create anticipation for the audience as though they could visualize the move before it happens, it adds to the realism as they expect it rather than just see it.
3. Staging
This one directs the audiences attention, its what they focus on and how the animator makes it so.
4. Straight ahead action - Pose to Pose
This applies to drawn animation more, but it is relevant still. Pose to pose is used a lot in computer animation and is used to maintain proportions. Straight ahead action is used for fluid movement
5. Follow through and overlapping action
This helps give the impression that the laws of physics exist within animation. Follow through represents the movement of body parts after a movement has been acted, as you do not just stop instantly after you wave your arm. Overlapping is the representation of speed, as certain parts of the body will move quicker than other parts.
6. Slow in and slow out
Just like overlapping action this is the movement of the body. This applies to the movement between poses, such as jumping/standing still.
7. Arcs
The majority of actions carried out by the body are done in a arched movement type. turning the head for instance is not usually a straight flat rotate, the person would usually arch their head to turn it or it would look un-natural.
8. Secondary action
This is basically background action, it alleviates some focus from the main character or asset meaning that the audience sees a second movement in the scene. It is key to note that they do not take away the focus from the main character but rather helps it.
9. Timing
Timing is fairly straightforward, it presents the amount of time it would take to for instance pull something towards you, the weight of the object would impact the time it took to pull it.
10. Exaggeration
This is used in cartoon animation mostly but does hold its place in realistic animation, usually movements are fast in frames and the eye struggles to register slight un natural movements. It is common in extreme poses such as the bending of the back.
11. Solid Drawing
This is the character and how they are drawn, they need to display their weight, anatomy and balance.
12. Appeal
This is important to characters, they must show likability - if that is the aim for the character or vice versa.