Anticipation: The anticipation to a move, usually the opposite way to which the character/element is going to move. To jump up you have to anticipate down, move left you anticipate slightly right. The exaggeration of the anticipation affects the style of the animation in many ways, largely defining the "cartoonyness" level of the piece. Subtle anticipation is more realistic, no anticipation is dead or mechanically impossible, and extreme anticipation would be highly cartoony, such as the work of Tex Avery.
Advanced Anticipation: Another way to think about anticipation is in reference to storytelling, and in using anticipation as a lifeline of communication with your audience. We use anticipation to direct the eye of the audience to key story points, as well as to the important part of the frame so that they don't miss a joke or important story element when it is revealed. We exaggerate anticipations even in subtle animation if it is necessary in order to make a key action or story point as clear as possible to the audience. The concept of anticipation is similarly employed when "selling" a joke – often the anticipation before the joke builds tension to make the joke even funnier, and occasionally the anticipation can be funnier and more entertaining than the joke itself.
Appeal: More ethereal than many of these terms, appeal is nonetheless something we should all constantly strive for in our animation. Appeal is the quality of character design, movement, and acting that audiences not only identify with, but on some level, enjoy and appreciate. Appeal is most important in character design, as great animation crippled by an unappealing character design will never be truly great. But similarly, appealing acting choices, and appealing movements (nice arcs, clear intensions, etc) can make all the difference between a mediocre scene and a great one.
Arcs: Refers to the circular, spiral, or figure 8 pattern that defines the path that almost every organic thing moves in. Especially in the polishing phase, tracking your arcs frame-by-frame and ensuring that they are smooth and dynamic (particularly on the wrists, nose, props, and feet) can add an incredible amount of appeal and life to your scene.
Blocking: Laying down the main story-telling key poses of your scene. Not worrying about in-betweens or break-downs. The bones on which to build the scene. They will be in the general right place in time but even that will change as you refine and start to add the later elements i.e. Breakdowns and in-betweens.
Breakdown: Once your key poses (See "Key Frame") are chosen and laid down, the "breakdown" is employed. Usually breakdowns favor one key pose or another ("favor" meaning: closer in time to one key pose or another), and are used to further define overlapping action, anticipations, arcs, etc.
Cons: Similar to "avar." A "con" is short for your character's selectable "controllers" which are used for posing and moving the character.
Clarity: Used to refer to the level of clearness in a pose, movement, or idea. You want your ideas to communicate as clearly as possible at all times, and clarity refers to how well you are achieving that goal. Clarity should be one of your primary goals as an animator.
Dirt: A term you may hear from your mentor. Adding "dirt" to a shot or a movement essentially means you are adding in some variation to the graph editor splines. Subtle keys that are very subtly "dirty up" the movement as a means of escaping a "spliney" or computery feel.
Exaggeration: Exaggeration in animation generally refers to how far beyond "normal" an idea or movement or pose is pushed. We exaggerate in order to make our ideas clearer, our poses stronger and more forceful, our characters heavier, our movements more exciting, and as a way of defining the overall style of our animation. The more exaggeration used, the more cartoony or stylized the animation.
Extreme: The furthest pushed moments in a shot. Not to be confused with a Key. You can settle into a key from an Extreme.
Function Curves: These are the representation movement and attributes in a 2D graph. The function curves are how your various rotations and translation are represented in the form of a graph. Any attribute that is keyable, including on/off or visibility, will have its own channel in the graph editor, though you cannot see them in the graph editor until the specific attribute has a key placed on it by the animator.
Floaty: A word used to describe a lack of weight in animation, usually as a result of incorrect body mechanics. If the hips are animated incorrectly, for example, the animation will look light or wrong, or as though the character is "floating." Any time the weight becomes unbelievable in a character, he will likely look as though he is being held up by a string tied to his head. You will likely hear mentors describe this as "floaty" animation, and it's something we all battle on a regular basis.
Flat Tangent: (see "Tangent") A flat tangent is used to ensure that there is no change in value between one graph editor key and the next, and to create a completely flattened curve. Flat tangents are used most often on the feet, to keep the translation values of the feet from changing between steps (to keep the feet on the floor when they aren't stepping). This stops the computer from creating "curved" in-betweens, which it is naturally inclined to do and results in feet slowly translating down through the floor or up into the air instead of resting naturally on the ground.
Hold: In animation, this refers to a stoppage of movement in a character or object, usually for the purposes of enhancing the clarity of an idea or pose. Generally, in feature animation, we do our best to avoid complete holds in favor of moving holds. (see: "Moving Hold")
In-between: Once you have created your keys (See "Key Frame") and breakdowns (See "Breakdown"), the next, and most refined, measurement of key moments is the lowly in-between. In-betweens refer to any frame that is not a key or a breakdown. Any pose that isn't essential to either telling the story, defining the character, or believable body mechanics would be an in-between. As such, it's easy to disregard in-betweens as unimportant afterthoughts, but in truth, bad in-betweens can ruin even the best of scenes, and we must be constantly vigilant against allowing the computer to do too much inbetweening on it's own, which consistently results in floaty (See "floaty") animation, and at the worst can make your character feel underwater, weightless, or completely unbelievable. You must be in charge of your own in-betweens. That's not to say that you must key everything on every frame! That would be a one-way ticket to poppy animation. Instead, simply make sure that you know exactly what your curves look like, and ensure that IF you are allowing the computer to in-between something for a few frames, you've looked at what its doing and have approved of it.
Key Frame: The most basic of the three types of frames (See "Breakdown" and "In-between"). A key frame (or key pose) is any moment in a scene necessary to describe the story, personality, or proper body mechanics and weight of the character. These are the main moments that you will plug into your scene, and should clearly and completely describe the ideas and intention of your shot.
Key: Saving a "key" on any object in Maya refers to saving a position or attribute value at a particular moment in time. If you move an object upward and then save that position, that is called "saving a key." Objects or characters with no keys will not have any movement, and their unkeyed attributes will not show up in the graph editor.
Knot: When using the graph editor you may hear tangent/keys referred to as knots. The computer calls everything a Key, but that is not always the case. For this reason some people call these knots.
Line of Action: This is the simplest line through a character that describes the action of that frame. If the line of action were taken from each of your frames and separated and played at full speed they would describe the action of the scene without the niceties of all the limbs. It's the force of a pose described in one line and all the other elements of the character compliment the main driving energy. This line is not always from the foot through the body and into the head. Look at this pose http://dreamick.com/images/_tarzan_drawing_.jpg. The line of action goes through the head but doesn't end there. It starts at the forward foot and terminates at the higher arm. If somebody is depressed it may start on the ground and go upwards then hook around like an upside down 'U'. If somebody is about to dunk a basketball it may look like a 'C' whereupon the ball would be at the end of the upper part of the C and the legs are being described by the lower part. The head in this instance is not represented by anything as it is secondary to the action that is taking place.
Momentum, Force, motivation etc: A body in motion tends to want to stay in motion yadda, yadda, yadda. This IS animation, how does something start to move? How does it stop? How does a character standing still start to move, and how, when he gets to where he is going, does he come to a stop? These are the forces that we as animators have to control and make believable. Get it wrong and EVERYBODY can see -- they may not be able to say what's wrong, but they'll know that something IS wrong. Humans are very perceptive at this, if something is moving too fast, 99% of people can recognize that something is wrong at a glance. If something stops too fast, people notice. Of course rules are made to be broken, look at the road runner and when he stops -- he does so in three frames, which not possible unless you hit a wall, but it works great in his world.
Moving Hold: In animation, this refers to a perceived stoppage of movement in a character or object, without actually bringing the character to a complete standstill, which would result in that character feeling dead or fake on screen. The creation of a moving hold essentially involves choosing your key pose, and then creating a subtly more extreme version of that key pose for your character to slowly move into from the "key pose." In this way, the character is always moving just slightly, but is holding still enough to satisfy the purpose of the "hold."
Overlapping: Not all parts of the body stop and start their movements at the same time. Overlapping action refers to the idea that "successive" parts of the body will be affected by whatever is directly above them in the body "hierarchy." (See "Hierarchy"). For example, a swinging arm will overlap like so: first the shoulder will move, then the upper arm, then the lower arm bends, then the wrist, then maybe even the fingers slightly. This is called "overlap," and is also often referred to as Successive Breaking of Joints.
Overshoot: An "overshoot" pose is one that goes even further than your main key pose, or your extreme. Basically, it "overshoots" the pose in any way. An example might be someone pointing their finger violently towards something. Your main "key pose" (See "Key Frame") will be the main pose that you want to end up in, but it might give it a stronger feeling to also create an "overshoot" pose where the pointing hand is just slightly even more extreme in it's pose (further away from the body) just a few frames before your main pose, and then you can ease back into your true key pose. Overshoots also often give you a great chance to create nice arcs (See "Arcs") and give your overall movement a more organic feel.
Pose to Pose: A method of animating whereupon you lay down your poses in a sequential fashion, not necessarily frame by frame, but one after another, until you reach the end of the shot. These poses are then your main blocking keys (See "Keys Frame"), and are the foundation of your scene that you will not build upon and begin refining. Not to be mistaken for a more stop-motion approach whereupon you would animate each frame, one after another until reaching the end of the scene. In computer animation, this frame-by-frame technique is to be avoided (except in special circumstances, such as a very fast action) because it will result in poppy, robotic movements.
Silhouette: If the character that is being animated were to be painted black so that all we saw was the shape of the space that the character inhabits, that is what is termed 'the silhouette'. We, as animators, are expected to make our poses read in silhouette so that the pose will read instantly and convey the emotion it's supposed to at the most casual of glances. There should be no ambiguity as to what is being portrayed, so be careful not to "hide" important gestures, facial changes, or props within the confines of the body. The more you can make things read in silhouette, the more it will read to the audience when seen fully lit.
