Animation Concepts

Animation Concepts

The information that is provided in this section is based on my interpretation and adaptation of the work of Tony White from the book The Animator's Handbook.

[ Inbetweening ] [ Using Key Points ] [ Superimposition ] [ Arcs ] [ Head Turns ] [ Eye Movement ] [ Walking ] [ Running ] [ Anticipation ] [ Realistic Touches ] [ Exaggerated Action ] [ Special Effects ] [ Assignment One ] [ Assignment Two ]

Inbetweening

This process focuses on the need for drawings (pictures) between two extremes or key positions. If more drawings are included the movement produced will be slower and if fewer drawings are included the illusion of faster movement will be created. To help animators an inbetweening chart is used. The numbering used in the chat is based on an even number of inbetweens because when two odd whole numbers are added together and divided by two the result is a whole number.

In the above inbetweening chart, frame-1 and frame-9 represent the key positions. Frame-5 represents the first inbetween half way between the key positions. Frame-3 indicates the need for an inbetween halfway between key frame-1 and the first inbetween. Similarly, frame-7 is the inbetween half way between frame-5 and key frame-9.

If an animator wishes to create the illusion of slowing down there would be more inbetweens at the end and the chart would appear as;

If an animator wishes to create the illusion of the action speeding up there would be more inbetweens at the beginning and the chart would appear as;

If an animator wishes to create the illusion of the action speeding up and then slowing down there would be more inbetweens at the beginning and end and the chart would appear as;

In certain circumstances in which a soundtrack for example limits the number of possible inbetweens the animator may be forced to use the idea of thirds to create the illusion of smooth motion and the chart would appear as:.

Using Key Points

These are useful when changing shapes and form between two key drawings. It requires the animator to select "key points" the link various midpoints of the two shapes. When these points have been chosen the first inbetween is drawn and then the process is repeated until all necessary inbetweens have been drawn. The following example illustrates this point. The inside geometric shape represents the first key position and the outside geometric shape presents the final key position.

The blue geometric shape represents the first inbetween, the green geometric shape represents the second inbetween and the final inbetween is represented by the red geometric shape.

Superimposition

This is required when both shape and position are changing. Demands greater visual judgment.

Steps:

In many instances movements or actions do not occur in a linear or straight line. If the procedure from above is followed for a pendulum swinging back and forth the result would not be an arc or curved path of motion. The blue circle is the diagram below illustrates this point.

It is necessary to superimpose the key frames and the first inbetween (breakdown sheet) in such a way as to have the arms and centers of the pendulum line up. The identified centers and arms act as the key points.

Straight line movement makes it appear mechanical. The illusion that is created is one of the parts of the face sliding across.

The eyes lead the direction of motion. When the head turn rapidly from side to side the eyes may blink or half close. If fewer inbetweens are used from open to closed or from closed to open the illusion created is one of being alert and intelligent. On the other hand if more inbetweens are used the illusion of sleepier or not with it is created. The movement of the pupils follows the same requirement as that of the head and that is all motion must be in an arc to create the illusion of natural motion. It is also important to note that when the pupil moves on the side of the eyeball there should be a slight stretching of the eyeball at the point of contact. When eyes blink the eyelid must be curved never straight across. If a sleepy blink is to be created the pupil should be carried down with the eyelid. A squint of disbelief is created when the top and bottom eyelids meet in the middle. The positioning of the pupil play a very important role in conveying the character's expression. For example:

Walking is based on the interaction of head, arms, body and legs and because of this complex interaction it is necessary to study it in sections.

With the front-on walks you use the same principles that were used with the profile walk. The key points are:

If a walk cycle is to be used the background must be animated and not panned. In simple terms the background must shrink in perspective as it moves into the distance. The principle of the profile walk is followed and that is - however far the contact foot slides on the cycle the background objects must move the same distance when they move in the background animation. When animating a background it is recommended that a cycle of action be used that can be repeated: for example a fence line or a set of telephone poles located along one side and when locating the position of the inbetweens they will always be positioned closer to the second key position rather than being in the center of two key positions.

The standard walk is one in which if the right leg is forward, the left arm is forward for balance. To make the walk of an individual unique, time should be

taken to observe how people walk. Take time to observe how an elderly man walks, or how a baby takes her first steps, or how a body builder moves , or how a tired runner walks after completing a 10 k run. It is important to remember that the anatomy of the character never changes therefore if you would like the body to appear to shrink you must have the legs bend at the knees or if the body is to appear to stretch then the body would move onto its tiptoes. Individuality can be created by using different head, leg and arm positions or by simply using positioning with key and passing positions and their respective inbetweens. For example you could draw the key and passing positions with the body in an upward motion and then drawing the respective inbetweens in a down position. This was used to create the Mickey Mouse walk which is referred to as a "double-bounce walk".

A general rule is that a basic walk can be drawn or filmed over eight frames. A more natural walk is usually completed over twelve frames. If you want to give the appearance of a fast walk it would be done over fewer frames and the opposite would hold true for a slower walk. Furthermore, varying the number of inbetweens between the key frames and the passing frame results in variations in the walk.

The rules that controlled how a walk was portrayed are in effect for the run but with a shift towards the more dynamic. The up and down movement is more exaggerated than in a walk because of the upward drive created by the push-off leg - the one in contact with the ground. In fact, the first inbetween or passing motion should have the runner off the ground. Arm movement is more vigorous and the use of the arms is critical within the total context of running. The arm is usually bent because it can be moved more quickly than a straight arm. In addition, the body lean is more pronounced and the stride covers a lot more ground.

In runs that require speed over a short distance and interval - a sprint, the runner must exhibit explosive movement with more body lean. In a more relaxed run - a conditioning jog, the runner presents the image of being more relaxed and upright. When a character is running uphill, the character's body should be leaning forward and the arms driving harder and if the run is downhill there should be an observable lean backwards and the arms should be more open.

The key positions dictate the type of run that is to unfold and because running it tied to speed it is recommended that the inbetweens be on the ones instead of the twos.

The major component for any action is the need to anticipate what is going to happen just prior to it happening. The anticipation that is created must be convincing to the audience. To better understand the concept consider the following examples.

One of the points to remember is that the eyes should always lead the way for the action.

To accurately portray a character, the weight of the character must be considered. The movements of a thin character running should appear quick and as if he were skimming along the surface of the ground while a heavy set person should appear to move more slowly. Tony White uses the concept of a bouncing ball to describe weight and he expresses the belief that the principles that apply to the bouncing ball apply to everything that moves.

As a ball falls towards the ground it starts to distort slightly and when it strikes the ground it loses its round shape and as it moves up from the ground it starts to elongate and then as the ball reaches its highest position it returns to its normal shape. Translating this to a character walking or running we would need the character to squash as it touches the ground and as the body leaves the ground there would be a natural elongation before returning to the normal shape. The degree of squashing would be tied to the activity and the weight of the character. The lighter the character the less squashing.

When a character is to transport a heavy object such as a bag of cement his whole posture and manner of movement must change. To maintain balance the idea is that the more weight that is to be carried the greater the degree on body lean in a backward direction. In addition to the backward lean there is a need to have flexing at the knees. There is also the need to change body posture from the initial point of holding the object, the start of a walk and finally carrying of the object from one point to another. For example:

Other points to consider is the size and strength of the character and whether the object is being carried in front (backward lean) or to one side (sideways lean) or if the object is being pushed or dragged.

It is important to use the concept of anticipation when trying to convey the idea that the character is carrying or moving a heavy object, For example if a heavy object is to be thrown it may be necessary to include a few swings before actually throwing the object.

A characters flexibilty helps convince the audience about what is happening. Remember that not all parts of an action occur at the same time but are rather a succession of movements. When considering an action the body part that leads the action must be determined and then which parts follow through. For example:

This example also demonstrates the succesive breaking of joints. As one joint breaks it immediatley returns (breaks back) allowing the next joint to lead. The joint break and return for this example would be first the shoulder joint, then the elbow, the wrist and fianlly the fingers. It is important to remember that there are limitations to flexibilty of joints and there should never be excessive breaking of joints resulting in impossible positions. Rule of thumb: use the limitations of the human body.

This is the effect of the main movement on parts that are secondary to the main movement. For example:

Free-moving objects attached to the main body of movement will exhibit an overlapping action.

A "take" is defined as an exaggerated reaction to an event. In simple terms the reaction that happens is more than what we would normally expect to happen. The more violent the "take" the greater the anitcipation in all of the movements. The "double-take" is more exaggerated that a simple "take" and as a result the inbetweens are more extreme.

An example of a take: A surprise encounter with someone the character does not like:

An example of a double-take: The above disgram is used and these additional inbetweens would occur between the squash and stretch.

Full body takes and double-takes follow the same basic ideas at the facial takes and double-takes. In addition to the squash and stretch techniques a drag, distortion or overlap could be used.

With drag one part of the action is delayed. For example when a character is to make a quick exit from a scene, the legs, arms and body leave and the head remains behind. Distortion requires the manipulation of scale and proportion. To create the effect of the face moving closer to the screen a wide angle effect is created by drawing or modelling the head bigger and bigger. To create the effect of the character disappearing into the background, the character can be drawn or modelled smaller and smaller. It is important to remember that squash and stretch techniques can be used in a more extreme fashion when animating cartoon characters and that the degree that they can be used with animating a human character is greatly reduced.

Sneaks can be classified as either slow or fast. Another name for a fast sneak is the tippy-toe sneak. The concept of a fast sneak is for the character to move quickly but with little or no noise. A slow sneak requires the character moving at a more leisurely pace. All sneaks focus on the character being on their toes. Remember, the key to a sneak is the character's attempt to move without being seen or being heard and that each sneak is particular to each character being portrayed. The next disgram illustrates the two types of sneaks.

The first figure is demonstrating a fast sneak. The character is hunched up and is as compact as possible in an attempt to create the illusion of not being seen. All motion is accomplished with the character on his toes. A fast sneak requires between ten and fourteen frames (pictures) per step. The second figure demonstrates a slow forward sneak. The character is stretched out with the body position backward and with the legs leading and the use of the toes to create the illusion of silence.The third figure demonstrates a slow backward sneak. Again the body is strectched out with the body position forward as the character backs out of the scene. A slow sneak requires between sixteen and twenty-four frames (picutres). To create the smoothest motion possible it is recommended that all inbetweens be done on the ones.

When a javelin strikes the ground the shaft vibrates for a few moments before coming to rest. This vibration is also referred to as a stagger. If a character were hit in the head by a snowball, the head should respond by a motion away and a motion forward before returning back to normal. If a boxer hits his opponent, the opponent should show a swaying motion before coming back to his normal boxing pose.

The goal when using special effects is to create a more realistic environment with attention to atmosphere required by the story whether it be for dramatic effect, a romantic episode or just a funny situation.

Props can be used to create the effect of wind - a flag fluttering, full sails on a ship, trees bent. To have a characater exhibit the effects of wind may require the character to lean forward as he in walking into the wind. The stronger the wind the more pronounced the body lean. If the character is wearing a hat, the illusion of wind can be created by having the character hold his hat on his head as he walks forward.To create the effect of a tornado you may have objects flying through the air.

The key is to remember that to create flowing water, the motion should be consistant and follow a particular path. The placement of objects in the water should convey speed and direction. To create more dramatic water motion whitecaps can be used. The use of reflection of moonlight or sunlight on the surface of water can vary from water that is still to the use of waves to show what happens to the reflection on moving water. If the reflection of a character is to be incorporated into a scene it should be noted that unless the water is still there should be some degree of distortion which is directly related to the amount of disturbance of the water. The best way to create the illusion of rain is to use diagonal lines with a background that is more subdued. The heavier the rainfall the more the background should be out of focus.

If a candle is to used a minimum of three key positions are required to produce the flame. A campfire requires a fire that flickers in a random pattern. It is important to note that the flickering of a fire has an effect on all objects in the scene.

When drawing a shadow remember that a shadow is cast along the ground and along the character or object. The shadow is always away from the direction of the light source.