Animation

12 Principles Of Animation

(1) Squash and Stretch

(2) Anticipation

(3) Staging

(4) Straight Ahead Action and Pose to Pose

(5) Follow Through and Overlapping Action

(6) Slow in and Slow Out

(7) Arcs

(8) Secondary Action

(9) Timing

(10) Exaggeration

(11) Solid Drawing

(12) Appeal

Solid DrawingSolid drawing can be translated into computer graphics terms as solid modeling and rigging. Effective modeling helps convey the weight and shape of a character. Character rigs can be designed character specific to create distinct movement and animation style. A strong silhouette, gives the viewer clues about a characters personality and style.

Appeal

Appeal or character personality creates an emotional connection between the character and the viewer. Characters must be well developed in order for the audience to have a clear understanding of the desires and needs that drive that characters actions and behavior. In many cases this includes the way a character moves or how the character is designed.

Appeal

The viewer should understand what is the motivation behind a character’s actions. Visually, this can be expressed by their posture, how they move, or how fast they react. An animated character needs to be visually believable and appealing. Which means that the characters actions and shape need to effectively communicate the character’s personality and attitude. The viewer is supposed to want to see what a character is doing.

Straight Ahead Action and Pose to PoseThere are two main approaches to traditional animation, Straight Ahead and Pose to Pose. Straight Ahead animation involves creating the first frame of animation and continuing frame by frame until the end of the animated shot. Straight Ahead animation is more practical for traditional animation than computer animation. Pose to Pose animation is more planned out and involves creating key poses need to perform the animated shot, and then filling in the frames in between.

Straight Ahead Action

3D animation and most traditionally animated films are considered Pose to Pose animation because they are based on key frames. Motion Capture is an alternative method for creating animation data, that is considered Straight Ahead Action. When an actor performs an action, the motion data is recorded and then applied to a digital skeleton. Since the data is recorded from beginning to end, motion capture animation is considered Straight Ahead Action animation. Rotoscoped animation and dynamic simulations are also considered Straight Ahead Animation.

Key FramesKeyframes are key moments that define an animated sequence. This process is based on traditional hand drawn animation where an animator draws the key positions of an animated sequence. In betweening is the process of filling in all the frames in between the key frames. In some cases a more experience senior animator creates all of the key frames for a sequence, and then a junior animator goes in a fills in all the frames in between.

Key Frame Interpolation

In most 3D software packages key frame interpolation is used to fill in the frames in between key frames. This process involves averaging the animation information of the key frames to find the characters position at a position in time in between the key frames.

Linear Interpolation

Linear interpolation is the simplest form of key frame animation. Linear interpolation averages the animation information from each key frame and produces evenly spaced in betweens. This can produce mechanical looking motion due to the fact that abrupt changes in speed and direction occur at every key frame. In the graph editor linear interpolation creates straight lines that connect key frames to one another.

Curved Interpolation

Curved interpolation averages the animation information from each key frame taking into account the change in variation over time. In the graph editor this produces a smooth curve that connects the key frames. By default most 3D packages use curved interpolation to create the frames in between key frames.

Frames Per SecondAnimated sequences are made up of single frames that are sometimes called still frames or stills. The number of frames that make up one second are determined by the final output. Standard NTSC video is 30 frames per second(29.97 frames per second to be exact), film is 24 frames per second, and video games frame rates are dependent on hardware capabilities.

NTSC stands for National Television System Committee.

3:2 Pull Down

In order to convert film to video, image sequences need to be converted from 24 fps to 30 fps using the 3:2 pulldown. The 3:2 pull down is the process that converts film footage at 24 frames per second to video footage at 30 frames per second. This process converts the film footage into fields which are then combined to create the video frames. There are 4 film frames for every 5 video frames.

Muybridge

Eadweard Muybridge is a photographer that studied motion and became famous for his photographs of figures and animals in motion. Muybridge used a special camera setup to capture images of a horse as it galloped through a corridor. He used a setup consisting of fifty cameras and tripwires to capture frames of the horse galloping. His photographs were able to prove that there is a point at which all of a horses hooves are off the ground at the same time. He used similar camera setups to study human motion and other animals.

Telecine

A Telecine is the machine that converts motion picture film to a digital format. Telecine also refers to the process of transferring film to a digital format. A Telecine allows film footage to be viewed on televisions, video cassettes, and computers rather that having to be projected using a film projector.

Walkcycle - Contact

The first key frame of the walk cycle is generally at the extended position where the feet are furthest apart. The characters weight is shifting to the front foot. This position is referred to as the contact position.

Walkcycle - Recoil

As the character’s weight shifts to the front foot, the knee bends to absorb the weight. This position is called the recoil position and is the lowest frame of the walkcycle. The main body is lower on this key frame to simulate the shift in weight.

Walkcycle - Passing

The character moves forward and the knee straightens on the weight bearing leg. This causes the body to move upward. This position is called the passing position because the non-weight bearing foot moves forward past the supporting foot with the knee leading the motion.

Walkcycle – High Point

As the body moves forward the heel of the weight bearing foot lifts off the ground transferring all the weight to the toe. This position is called the high point as the weigh bearing leg is full extended pushing the body forward. The main body begins to fall forward and the other leg swings forward to catch the character’s weight.

Walkcycle - Contact

The weight shifts to the other foot and now the character is in the exact opposite position as the first key frame where the feet are farthest apart. This is the contact position.

Cartoon Animation by Preston Blair

The Animator’s Survival Kit by Richard Williams

The Illusion Of Life by Frank Thomas and Ollie Johnston

Animals In Motion by Eadweard Muybridge

The Human Figure in Motion by Eadweard Muybridge

*Digital Character Animation 2 by George Maestri

Animation Reference