Animation is a method in which figures are manipulated to appear as moving images. In traditional animation, images are drawn or painted by hand on transparent celluloid sheets to be photographed and exhibited on film. Today, most animations are made with computer-generated imagery (CGI). Computer animation can be very detailed 3D animation, while 2D computer animation (which may have the look of traditional animation) can be used for stylistic reasons, low bandwidth, or faster real-time renderings. Other common animation methods apply a stop motion technique to two and three-dimensional objects like paper cutouts, puppets, or clay figures.
Commonly, the effect of the animation is achieved by a rapid succession of sequential images that minimally differ from each other. The illusion—as in motion pictures in general—is thought to rely on the phi phenomenon and beta movement, but the exact causes are still uncertain.
Animation is more pervasive than many people know. Apart from short films, feature films, television series, animated GIFs, and other media dedicated to the display of moving images, the animation is also prevalent in video games, motion graphics, user interfaces, and visual effects.
Common Computer Animation Terms
In this article, we bring you some of the most commonly used terms in animation.
ACCENTS: Animators need to “hit the accents” in a line of dialogue. By “accents”, we’re not talking here about a regional accent – say a British or French accent – we’re talking about making it clear in the poses that the character is speaking the line of dialogue. In this case, an “accent” is the part of the line of dialogue that has an emphasis and needs to be punctuated.
Accents can be hard or soft. What is the difference between a hard accent and a soft accent? In animation terms, a soft accent eases in, and a hard accent bounces back.
ACTING: Acting for animation is the art of taking on board the personality and character traits of another and translating them to a previously inanimate object, a CG model, a puppet, or a drawing. It is moving these in such a way as to lead your audience to believe that this ‘thing’ can think for itself.
It is almost expected that an animated character because it is not ‘real’ can exaggerate movement or the timing and anticipation of that movement. All animation works with this convention. All forms of animation offer the animator the opportunity to create minutiae of movements, although some are more costly (in terms of time) than others. With stop-motion and drawn animation, each thing that moves has to be worked by hand but with CG there is the opportunity to let the software lend a helping hand. This means that you can have a CG character that has movement in every frame, but a stop-motion puppet that moves without a pause seemingly is less believable. A stop-motion puppet should be allowed to rest or remain motionless from time to time. It is better to let a gesture read, and to hold, than for a character to remain on the move constantly.
AMBIENT OCCLUSION: In graphics, ambient occlusion is a shadowing technique used to make 3D objects look more realistic by simulating the soft shadows that should naturally occur when indirect or ambient lighting is cast out onto your scene. Ambient occlusion shading is fake indirect shadows that are added into the render by rays that get cast out from each surface on your geometry. If these rays come into contact with another surface, that area will become darker. If they don’t find another surface, the area will stay brighter.
Ambient occlusion is great for softening the overall lighting in your scene if it’s too bright. There is no need to add additional lights because ambient occlusion does not work in the same way as “final gather” which must use a light source to cast out rays. Ambient occlusion is also great for visualizing a model that hasn’t even been textured yet.
ANIMATIC: An animatic is a string of storyboard images edited together with sound to illustrate how a sequence will flow in motion. It’s a next-level technique after storyboarding. They aren’t always necessary, but they do provide a fuller sense of what the finished project will look like. While animatics are usually all the time in animation, even live-action films will use them, especially for complex action or visual effects scenes.
| Animatic | Storyboard |
| An animatic is an animated storyboard. The same images you’ve already created as a storyboard are now put into a video and can include dialogue, sound effects, and music. It requires a storyboard to be completed beforehand but there is a clear difference between a storyboard and an animatic. | A storyboard is a visual representation of a film sequence and breaks down the action into individual panels. It is a rough approximation of how the sequence will unfold. A storyboard is similar to a trial run for your finished film, video, or commercial in what looks like a comic book. |
ANIMATION LAYER: In animation and graphics software, layers refer to the different levels on which you place your drawings, animations, and objects. The layers are stacked one on top of another. Each layer contains its graphics or effects, which can be worked on and changed independently of the other layers. Together all the layers combine for a complete graphic or animation.
In most cases, when you open a new file in a software program, you see only the base layer of the file. You could do all your work there, but you would end up with a flattened file that is difficult to edit and work with. When you add layers on top of the base layer as you work, you expand the possibilities of what you can do with the software.
ATTITUDE: The feelings and thoughts of your character! When you animate you should always have clear in mind the type of attitude he/she has to better perform the scene!
BACKGROUND: In traditional animation, a background layout is the line drawing of the background for a scene. It is not the finished background painted in a color that you see on the screen.
Layouts are drawn from storyboards that define the action and perspective in the scene. Because storyboard artists draw backgrounds in a rough, simplified style, background layout artists take them to the next level by defining the detail and perspective. Layout drawings are then given to the background painters to colour and complete the visual style.
Depending upon the style of the film or show, the lines of the layout drawings may be visible in the finished background that is used in the final production. Or the visual style may be void of the linework, thus the layouts serve as a guide for the painters.
BALANCE: It is a principle of design; the arrangement of elements that makes individual parts of composition appear equally important; an arrangement of the elements to create an equal distribution of visual weight throughout the format or composition. If a composition appears top- or bottom-heavy and/or anchored by weight to one side, it is not visually balanced.
Types of balance:
- Symmetrical balance (or Symmetry) means that the work of art is the same on one side as the other, a mirror image of itself, on both sides of a center line.
- Asymmetrical balance (or Asymmetry) means that the two halves of the work of art are different, however, try to create balance. In other words, although the sides may not be exactly the same, there will be elements that interact in a way that makes each side equally important.
- Radial symmetry means the weight of the image or form radiates from a center point.
BLEND SHAPES: Blend shapes create the illusion that one shape changes into another in a natural-looking way. You might use one, for example, to animate a character’s mouth moving from a neutral shape into a smile.
This works by using a duplicated version of the object, which is then manually adjusted to another shape. You can then use blend shapes to blend or morph between these, and it creates the illusion of an object changing its form.
Using this method, animators can mix and match blendshapes to form any number of combinations between the prepared and linked blendshapes. A frown can be mixed with a smile to form an apologetic expression. A blendshape with pursed lips can be mixed with frowning eyes to form an expression of determination or a look of disapproval.
BODY MECHANICS: Body mechanics is the way we move when we walk, run, take the stairs, and so on… How the body reacts and moves during these actions!
Character animation at its very basic level is essentially recreating real-life movements, whether it’s 2D animation or 3D. Sure, much of this consists of exaggerating these real-life actions to increase the appeal and to create something more entertaining to watch. It’s our job, as animators, to understand how the human body moves and reacts, not only that but also there, sometimes some time about how animals and even inanimate objects behave. To understand animation, and to create believable movements, we must study how things in the world move.
BREAKDOWN: Breakdowns are the large gaps between the keys. By placing key action on breakdowns, you can loosen up your animation, and offload a lot of your animation work onto an inbetween drawing – which is far easier than creating yet another key.
Here are some sample images from the handout. This thumbnail is pretty clean (cleaner than it really needs to be – yours can be much looser, as long as you can follow the action). The two keys are on #1 and #21, the breakdown in red, with the antic and overshoot in blue. With this one image, the physical action is pre-animated! The timing estimate below also allows you to plan out the timing and spacing of the entire scene in one image.
The breakdown here is #8 (in red). Notice how the head moves down while the arm moves up. It’s the breakdown that creates the flexibility of the action and stops it from being a bland tween.
BREAKING JOINTS: Breaking joints basically refers to rotating joints in the opposite direction to their normal bending. In the real world, this wouldn’t be physically possible without actually breaking a joint. In animation, bending the joints in the opposite direction will add a lot of flexibility to a movement, and is typically used for a more cartoony style animation. Since you’re only breaking the joint for a frame or two when played back at full speed it isn’t noticeable. It is closely related to the principle of overlapping action, but applied to an entire chain, like an arm for instance.
CAMERA SHAKE: Camera shake is a term used to define the act of accidentally shaking a camera during shooting due to unsteady hands, which results in blurry images. This generally occurs more often if you’re shooting on a low shutter speed or with a heavy lens, and can be avoided by using a tripod and cable release setup.
Shaky camera shots can be a great addition to car chase scenes or in any other scene that tries to highlight movement. Filming a perfectly still shot, and adding the camera shake effect in post-production is probably the best way to make sure you’ll end up with a great final cut of your video.
CHANNEL BOX: The term channel is, for the most part, interchangeable with attributes. You can think of a channel as a container that holds the attribute’s value. The Channel Box is an editor that lists a node’s attributes for quick access. The Channel Box displays the node’s attributes, which are most frequently keyframed for animation.
CONSTRAINT: An animation constraint is a special type of controller that can help you automate the animation process. You can use constraints to control an object’s position, rotation, or scale through a binding relationship with another object.
A constraint requires an animated object and at least one target object. The target imposes specific animation limits on the constrained object.
For example, to quickly animate an airplane flying along a predefined path, you can use a Path constraint to restrict the airplane’s motion to a spline.
You can use keyframe animation to toggle the constraint’s binding relationship with its targets over a period of time.
Common uses for constraints include:
- Linking one object to another over a period of time, such as a character’s hand picking up a baseball bat
- Linking an object’s position or rotation to one or several objects
- Keeping an object’s position between two or more objects
- Constraining an object along a path or between multiple paths
- Constraining an object to a surface
- Making an object point toward another object
- Keeping an object’s orientation in relation to another
CYCLE/LOOP: In animation, a walk cycle is a series of frames or illustrations drawn in a sequence that loop to create an animation of a walking character. The walk cycle is looped over and over, thus having to avoid animating each step again.
Walk cycles can be broken up into 4 key frames, namely Forward Contact Point, Passing Pose1, Back Contact Point, and Passing Pose 2. Frames that are drawn between these key poses (traditionally known as in-betweens/Inbetweening) are either hand-drawn or use computer software to interpolate them.
DYNAMIC SIMULATION: Dynamics is the simulation of motion through the application of the principles of physics. Instead of assigning keyframes to objects to animate them, you assign physical characteristics that define how an object behaves in a simulated world. The dynamic bodies are converted from the objects created, and defined through dynamic attributes, which affect how the objects behave in a dynamic simulation. With dynamic simulation, you can create many impressive effects such as explosion, flood, storm, tornado, ocean, etc., for animations and computer games.
EXTREMES: Extremes are drawings or images that are at the beginning and the end of a pose. They are also known as preliminary drawings. Extremes refer to the farthest posture of a character. They also refer to the effect in a direction of motion. There is a difference between extremes and keys and also between extremes and breakdowns.
FADE IN / FADE OUT: The Fade In/Fade Out behavior lets you dissolve into and out of any object by ramping the opacity of the object from 0 percent to 100 percent at the start, and then back to 0 percent at the end. You can eliminate the fade-in or fade-out effect by setting the duration of the Fade In Time or Fade Out Time to 0 frames.
The Fade In/Fade Out behavior is useful for introducing and removing animated elements. For example, you can apply the Fade In/Fade Out behavior to text that moves across the screen to make it fade into existence, and then fade away at the end of its duration.
FISH EYES (in posing): How do you make a blank stare even blanker? Have the character’s eyes face slightly (or even more than slightly) away from each other — reverse cross-eyes, if you will. It’s usually used to make the character look unintelligent or dumbfounded, causing it to become known as “derp eyes” in some Internet circles. In real-world English, this is called “wall-eye” or “squint”, and in medical jargon “exotropia”.
Sometimes, however, they can be used for a more serious effect, such as showing that a character’s mental stability is loosening, emphasizing an emotion (commonly anger or happiness); sometimes this is done when a character mocks another, or to emphasize that they act in a way unlike they usually do. They may occasionally be the result of plain old physical eye damage.
FK – IK (FORWARD AND INVERSE KINEMATICS): Forward kinematics uses a top-down method, where you begin by positioning and rotating parent objects and work down the hierarchy positioning and rotating each child object.
Basic principles of forward kinematics include:
- Hierarchical linking from parent to child.
- Pivot points defining joints between objects.
- Children inheriting the transforms of their parents.
These principles are fairly forgiving. As long as everything is linked together and the pivots are located at joint locations, you can successfully animate the structure.
Inverse kinematics (IK) uses a goal-directed method, where you position a goal object and 3ds Max calculates the position and orientation of the end of the chain. The final position of the hierarchy, after all of the calculations, have been solved, is called the IK solution. There are a variety of IK solvers that can be applied to a hierarchy.
Inverse kinematics starts with linking and pivot placement as its foundation and then adds the following principles:
- Joints can be limited with specific positional and rotational properties.
- The position and orientation of parent objects are determined by the position and orientation of child objects.
Because of these additions, IK requires greater thought about how you link your objects and place pivots. Where many different solutions for linking objects may be suitable for forward kinematics, there are usually just a few good solutions for any given IK approach.
Inverse kinematics is often easier to use than forward kinematics, and you can quickly create complex motions. If you need to edit those motions later, it can be simpler to revise the animation if you are using IK. It also is the best way to simulate weight in an animation.
FOREGROUND: An element that is up close and usually partially illustrated with the remainder of the object situated off the page. The foreground is used in conjunction with the mid-ground and background areas of an environment.
FRAME RATE (FPS): Frame rate, is the speed at which those images are shown, or how fast you “flip” through the book. It’s usually expressed as “frames per second,” or FPS. So if a video is captured and played back at 24fps, that means each second of the video shows 24 distinct still images.
Frame rate greatly impacts the style and viewing experience of a video. Different frame rates yield different viewing experiences, and choosing a frame rate often means thinking about multiple factors, such as how realistic you want your video to look or whether or not you plan to use techniques like slow motion or motion-blur effects.
GHOSTING: Ghost objects let you see how an animation moves through a scene. Unlike Motion Trails, which simply use a line to illustrate where an animated object moves, a ghost object shows a semi-transparent representation of the object at the points in time you specify. Cached playback lets you ghost deformed meshes, and improves the speed of playback.
The opacity and the color of ghosts make it easy to differentiate between the individual frames of your animation. By default, the opacity gradient ramps down linearly from the ghost closest to the current frame to the ghost farthest away.
GIMBAL LOCK: A gimbal is a pivoted support that may rotate freely along a single axis. When you combine three gimbals, you achieve the most commonly observed arrangement: Pitch, Yaw, and Roll (or XYZ as you’re probably more used to seeing it.) Simply put, Gimbal Lock is the loss of one degree of freedom which occurs when two gimbals are rotating parallel to each other. Gimbals never actually “lock” — which makes the task of managing this issue that much easier. As it is experienced in 3D animation, there are many ways to overcome this annoyingly common obstacle.
HOOK UP or CONTINUITY: Animators are commonly assigned to work on single shots on a project, which means there will be another shot, animated by another animator, on either side of theirs. These shots must play together in continuity, meaning that there must be a smooth flow from one to another. The pose of a character at the end of one shot should be the same pose in the next shot, or else the shots won’t “hook up”.
In animation terms, hookups are about continuity, and on a film project, it is the animator’s responsibility to make sure that their shot hooks up with the shots on either side of theirs.
IDLE: Mostly used in games, is a cycle where a character just stands and breathes! We can use any type of pose we need (a neutral pose or an action pose) and it is conceived to be shown as an infinite loop!
These sorts of animations are largely popular with action games, where players may rarely be idle and thus serve as easter eggs. Some of the first games ever to introduce idle animations on a mainstream basis were Door Door and Maziacs; the sprite taps his feet, blinks, and sits down. This trend spread to many other action genre games, becoming more complex as allowed by the advancing hardware. For example, in Donkey Kong Country 2: Diddy’s Kong Quest, Diddy Kong juggles a few balls if the player offers no controller input for a few seconds.
Idle animations in modern 3D games are used to keep them realistic. In general, games meant for younger audiences are far more likely to have complex or humorous idle animations, while games for older people tend to have more basic idle animations. For example, in Super Mario 64, Mario will occasionally look around, and eventually fall asleep, while in other games, steady breathing suffices as an idle animation.
INBETWEEN/TWEENING: Inbetweening, also commonly known as tweening, is a process in animation that involves generating intermediate frames, called inbetweens, between two keyframes. The intended result is to create the illusion of movement by smoothly transitioning one image into another.
KEY POSES: These are the key moments that your character must show in the scene. Without these Key Poses, the actions or story may not be as strong or even lost in translation. Key Poses are the most important action in your scene. If done right, it will properly show the audience the character’s emotions and actions of the scene.
LINE OF ACTION: Line of action is an imaginary line that describes the direction and motion of a character’s body and is the leading force of his action. A good line of action improves the character’s poses, makes the character look more dynamic, energetic, and alive. It can also affect the staging and composition of the scene. Poses with a good line of action are clearer and more understandable for the audience. There are 3 types of lines of action, the C, reverse C, and S curves.
LOCATOR: Locators are like the Swiss army knife of 3D; playing a key role in animation, it serves many important functions: targets, controllers, parents, manipulators, selectors, and even joints. Since locators are just items, they have their own set of properties, the most important being their own transforms, and as such, they can be positioned and animated independently of Mesh Items in a scene. This might not seem so exciting by itself, as locators don’t even render, but when working with constraints, modifiers, and influences, you quickly discover how useful they really are, serving as the virtual backbone of any rigging setup. As such, there are some special properties associated specifically with locators.
MODEL SHEET: In visual arts, a model sheet, also known as a character board, character sheet, character study, or simply a study, is a document used to help standardize the appearance, poses, and gestures of a character in arts such as animation, comics, and video games.
Model sheets are required when multiple artists are involved in the production of an animated film, game, or comic to help maintain continuity in characters from scene to scene. In animation, one animator may only do one shot out of the several hundred that are required to complete an animated feature film.
MOMENTUM: It is a physics principle based on the character’s motion depending on its mass and velocity. Is the impulse, the boost, the power of the movement! Momentum also depends on the direction of the motion so deflecting a moving object is considered a change of momentum. The principle of Force and Momentum says that an unbalanced force will change an object’s momentum; the bigger the force, the quicker the momentum changes. For moving characters, this change in momentum could result in increasing or decreasing a character’s speed or it could be a change in direction (such as making a turn). Among physicists, the principle of Force and Momentum is known as Newton’s Second Law of Motion.
MOTION BLUR: Motion blur is the apparent streaking of moving objects in a photograph or a sequence of frames, such as a film or animation. It results when the image being recorded changes during the recording of a single exposure, due to rapid movement or long exposure.
In computer animation, this effect must be simulated as a virtual camera actually does capture a discrete moment in time. This simulated motion blur is typically applied when either the camera or objects in the scene move rapidly.
MOTION CAPTURE – MOCAP: It is the process of digitally recording the movement of people. It is used in entertainment, sports, medical applications, ergonomics, and robotics. In film-making and game development, it refers to recording the actions of actors for animations or visual effects. A famous example of a movie with lots of motion capture technology is Avatar. When it includes full body, face, and fingers or captures subtle expressions, it is also referred to as performance capture.
MOVING HOLD: A “moving hold” is basically just a way to have your character hold a key pose for a long time without looking dead. Moving holds can be really tricky. It’s so easy to have your character moving too much, giving the performance a floaty CG feel, or to have the character freeze too much, which is instant death, especially in CG animation. You’ve worked so hard to convince your audience that your character is a living, thinking, feeling being, but no matter how much you’ve sucked them in, a frozen character instantly appears dead, and all your hard work goes down the drain as the audience remembers they’re just looking at a cartoon.
OVERLAPPING ACTION: It is a tool used by animators to emphasize the action and mood of the character. When a character moves across the screen some parts of the body move before or at different rates than others. Some parts of the body will lead the action and some parts will follow the main action.
OVERSHOOT: This principle says that any object that is stopping, will miss the stop point a bit before stopping eventually, reminds a pendulum a little. to understand this in a quick way you could try it for yourself: put your right arm in front of you and make a fist while the arm stays straight.
PAN-PANNING (CAMERA): Panning is moving the camera across a wide background and stopping at significant spots where the action is taking place. To pan scenes in Flash, simply create a background image that is significantly larger than the stage. Create a motion tween that moves the image across the visible portion of the stage.
PASSING POSITION: The passing position is the mid-way position between two keys. In all other actions, the first inbetween position between two keys would be called a breakdown. With walks, it is known as passing position.
The passing position is where the trailing leg is coming halfway through to the front while the body is lifted upwards over the straight contact leg and the arms are pretty much by the sides.
PHONEMES: Phonemes are the smallest individual units of sound that are combined to form speech. A phoneme shape refers to the position of the lips, teeth, tongue, and jaw required to utter a phoneme or a specific sound of speech.
For example, the phoneme shape for the phoneme /m/ consists of lips that are pressed together, whereas the phoneme shape for /l/ consists of lips that are not round and that are slightly apart, with the tip of the tongue pressed lightly to the gums behind the upper teeth.
POSE TO POSE: Pose to pose is a term used in animation, for creating key poses for characters and then inbetweening them in intermediate frames to make the character appear to move from one pose to the next. Pose-to-pose is used in traditional animation as well as computer-based 3D animation.
