We can see in the following illustrations that when squash and stretch is applied to the animation of a bouncing ball the action is enhanced. As a general rule you should ensure that the volume of the object you are animating is not changed; it should neither gain nor lose mass.
While the shape of the characters and objects may change, they may be flattened or extended; they should not lose or gain volume. This will help the animation to remain in scale with the rest of the environment. Perhaps the most extreme example of squash and stretch can be found in the work of Tex Avery, particularly in some of his masterly pieces of work for MGM in the s, in which he took all kinds of liberties with volume.
He used a range of techniques Basic principles 23 Figure 1. More excessive use of squash and stretch on facial features will give you a cartoon feel that may tend to look less naturalistic. When using squash and stretch to achieve naturalistic animation you should take into account the nature and properties of the material you are dealing with. Give careful consideration to the weight and density of the object and allow for any natural flexibility of the material; that way your animation will be believable.
It is important to avoid any unnatural rubberizing of objects — unless you are animating rubber. It is easy to overdo it. Rigidity almost never occurs in organic forms except boulders and rocks and is usually only seen in such man-made objects as cars, furniture, bottles, buildings, etc.
Even the animation of some of the rigid forms will benefit from a limited application of this technique and, for a more cartoon effect, squash and stretch can bring life and characterization to anything. Overdo it and you could easily end up with animation that has no snap and lacks credibility!
Remember, you may want to rubberize the action without animating rubber. However, if the object is simply a prop it may lose credibility if squash and stretch is applied too liberally — or even at all. Both are very different ways in which animators approach the making of the work, and both have their unique qualities and specific advantages and disadvantages.
The terms straight-ahead and pose-to-pose simply describe the separate processes and the way in which subsequent images are created. Within straight-ahead animation the animator makes the first drawing, or sets the position of the model for the first frame of animation, and then goes on to make the second drawing or set the second position for the second frame of animation.
The animation is continually made one frame after the other in chronological order: 1, 2, 3, 4, etc. The images are compiled in this way until the sequence is complete, creating animation in a straight-ahead manner. This process of straight-ahead animation is the only process available to stop-frame model animators as the only way that it can be done is a frame at a time, one after the other. If you recall, this is the way in which you made the flip book animation earlier. Making pose-to-pose animation or key-frame animation as it is increasingly known is entirely different.
The animator will Basic principles 25 Figure 1. Key-frame or pose-to-pose animation is made by creating the important moments of an action first and subsequently creating the frames in between these moments. The principal advantage of pose-to-pose animation is the capability it allows for the addition or subtraction of frames within the sequence. Changes to animation timing are easily achieved using this method. Once this has been done they create the next drawing or set the model for the next frame of animation depending upon a key moment of the action.
The important aspect of poseto-pose animation is that this drawing or position does not need to be frame 2. This can be almost any frame within the action and is determined by the nature of the action.
Subsequent drawings are made of key moments of the action hence the term key frame without the necessary frames in between the key frames. So, for instance, an action of a figure throwing an object may be broken down into just a few key positions, picking up on all the major transitions of the action. Using this method it is possible to sketch out an entire sequence using rough key drawings, enabling the animator to construct the entire action.
From these, with practice, it is possible to make a fairly reliable assessment of the development of the action without having to create all the drawings. Using key drawings it is also possible for animators to more easily synchronize key moments within an action to pre-identified frames that appear on the dope sheet.
This is most important when animating dialogue. This is covered in more detail in the chapters covering lip-sync and dope sheets. It is also easier for an animator making classical 2D animation to keep the characters on model and to ensure that proportions do not change throughout the sequence. Disadvantages of pose-to-pose animation The disadvantages are that the animated action may at times, in the wrong hands, appear to be a little stagy, stiff, and have the appearance of being constructed and somewhat unnatural.
For some forms of cartoon animation this may not be a problem but become part of the stylistic approach. However, for more naturalistic actions, particularly in those actions that have many complex elements, each with its own specific timing requirements, it may actually become more difficult to break down each element into keys and inbetweens. The disadvantages of pose-to-pose animation are sufficient to warrant a mixed approach to animation, using both straight-ahead and pose-to-pose within a single sequence.
Advantages of straight-ahead animation The great advantage of straight-ahead animation is that it encourages a liveliness of approach to the animation. It is unencumbered by an overstructured approach to the animation, you can go with the flow. This is very useful for actions that have a lot going on, with separate elements having their own timings. Trying to structure such actions Basic principles using keys may kill the action stone dead.
Straight-ahead animation may often allow for a more creative approach to animation timing and surprise you with happy accidents, those moments when apparently, quite by chance, you create something more wonderful than you first intended. Disadvantages of straight-ahead animation This puts a great deal of added pressure on the animator, as corrections cannot easily be made by adding frames within an existing sequence. Straight-ahead animation can lack structure by its very nature and demands a good deal of concentration on the part of the 2D classical animator, something that is an everyday occurrence for the 3D stopframe animator.
Using this method, making one drawing after the other, it may be easy to allow drawings to change proportion throughout a sequence, gaining or losing mass. The difference does not have to be very great from one drawing to the next, but taken over many drawings this difference may well become very noticeable. It is also more difficult to hit specific points within a sequence and there may be a tendency to allow the duration of specific scenes to grow or shrink, which may cause more difficulties for the director trying to keep to the initial timing of the animatic.
At this stage the sequence is completed with key frames with no frames in between the key action. The sequence is initially broken down into individual poses; subsequent animation is then added to get the action from one pose to another pose — hence the name. You will notice that there are initially far fewer drawings of frames within the sequence than the equivalent using straightahead animation.
In order to complete a sequence of poseto-pose or key-frame animation properly, it is necessary to add the frames that appear between the keys. These drawings or additional frames are known as inbetweens — because they appear in between the key frames.
Once these are added you will notice that the number of frames for each of the sequences is the same, or very nearly. It is standard practice in 2D classical animation to illustrate animation timing breakdown with the use of a small chart or 27 28 Animation: The Mechanics of Motion Figure 1. In this case it is a simple ball rolling down a slope. The two key frames are positioned at the beginning and end of the action, in this case Key Drawing A and Key Drawing B.
These are used to indicate key drawings and the inbetween drawings that appear between them. Now we need to take a look at how to vary the timing of an animation to create the dynamic required. To create variable timing we need to vary the position of the inbetweens in relation to the keys. This kind of variable timing is achieved by varying the distance between drawings. Being trained as a classical 2D animator, I prefer the more traditional term, but either will do.
Basic principles 29 Figure 1. These timings are usually seen at the beginning of actions as the inertia of an object is gradually overcome. The greater the inertia an object possesses, the longer it will take to build up momentum, which may result in a more pronounced slow out action.
Slow ins are typically used as an object slows down before coming to rest. An object with little mass and momentum will shed its kinetic energy more quickly than a heavier object and will slow down more quickly.
Complex animation timings can be achieved quite simply if the proper structured approach is taken. Step 1. Checking the animation timings marked down for this sequence, we can see that there are three drawings that appear halfway between our two key drawings 1 and 5. We can see in this instance that drawing 3 is halfway between the two keys. This is known as a breakdown drawing; as its name suggests, it breaks down the action. So this is the first drawing of the sequence to be made other than keys.
Placing key drawings 1 and 5 on the lightbox, we then make drawing 3, which appears halfway between the two as per the animation timings. Step 2. Having made the first breakdown drawing, we can now go on to make the rest.
Using the first key drawing 1 and the breakdown drawing 3 just made, we can create the next inbetween, in this case drawing 2. Once again, you will notice on the animation timing chart that this drawing appears halfway between key 1 and drawing 3. So by placing key drawing 1 and drawing 3 on the lightbox, we can then make drawing 2. Step 3. The next process to complete the short sequence is to create the final inbetween 4. To do this, follow the same process as before, making drawings that appear halfway between two other drawings keys or inbetweens , take key drawing 5 and the inbetween you have just completed 3 to create the next inbetween 4.
By breaking the timing down in this manner we can mostly achieve all the animation timing we desire simply by positioning drawings halfway between keys, breakdown drawings and other inbetweens.
Occasionally, it is necessary to make inbetweens that appear a third of the way between keys. These are usually a little trickier to make, though once you have more experience they are very useful in creating the exact animation timing you require. Such spacing will create a constant speed throughout the action, making for a most unrealistic bounce.
Basic principles 31 Figure 1. This is still an unrealistic action for a bouncing ball. We have a slow in as the ball moves towards the middle key drawing number 6 and a slow out as it moves from the middle key to the end key.
This will result in the ball decelerating as it moves from the first key towards the middle key slow in and it begins to speed up as it moves away from the middle key towards the third key slow out. The variable timing on this action will give the desired result, a more realistic and believable action, as we saw in the earlier example. More cushioning is added to extend the acceleration or deceleration periods of an action. A word of warning!
Objective On completion of the exercise you should be able to create a series of animations with variable timings.
In order to understand the basic principles we have covered so far we need to put them into practice. The following animation exercise will give you a chance to play around and discover these things for yourself.
Animation, rather like riding a bicycle, is learned through experience, not simply by reading about it. Also remember that animation skills are transferable skills; if you develop a good understanding of dynamics, a sense of animation timing and performance within one medium you will be able to carry these over to another medium with little additional effort.
That is why many of the major CG animation studios are keen to employ people with solid 2D classical animation experience. It is important to remember that the object of these animation exercises is concerned with movement and timing, not good draughtsmanship or design, so for the purposes of all these animation exercises you should keep your images as simple as possible. You should consider all these animation exercises as an opportunity to develop basic animation skills upon which Basic principles 33 you can build, regardless of the specific animation discipline you work in.
Also, as a general rule, naturalistic animation is more difficult to achieve than cartoon animation, so for this reason you should try to make all your animation within these exercises as naturalistic as you can. A tennis ball 2. A cannonball 3. An inflated balloon.
This drawing should be placed on a lightbox first, all subsequent animation being done on separate pieces of paper placed over this initial drawing. You may find it helpful to make, on a separate piece of paper, a path of action that each of the balls will make.
These will act as a guide when you begin to animate. Obviously they will vary from one another because the actions of each type of ball will vary. Each of the different balls will build up momentum. A heavy object such as a cannonball will take a lot more effort to move but, once moving, takes a lot more stopping than a tennis ball, for instance. These factors will help to give each ball its own very distinctive movement characteristics.
You might want to try that once you have completed this successfully. Notice how the bounces are very similar to one another as they descend the steps and get smaller once the ball reaches the bottom.
The second animation should reflect the realistic action of a cannonball. Notice how the cannonball bounces much less than a tennis ball on each of the steps. However, the cannonball would continue to roll much further than the tennis ball once at the bottom of the steps. Ths is due to the amount of momentum an object with more mass has built up. On this path of action there is more bounce than the cannonball, though the action has more drift than the tennis ball.
The bounce remains quite quick, though the fall through the air is slower due to air resistance. Notice how the path of action may vary slightly between bounces. This is due to the air resistance such an object with low mass and large surface area will encounter. Once the balloon reaches the bottom of the steps, the bounces quickly lose height and there is little forward movement. The momentum is quickly lost due to the lack of mass and large surface area. Once you have completed your animation you should make a thorough analysis of your work before attempting any alterations.
At this stage you may learn just as much from making an unsuccessful piece of work as one that works first time. Indeed, it is more likely, as it will force you to analyse your work much more closely. Now that we have covered the basics of animation timing we can move on to take a look at some of the more involved and complex aspects of animation that, coupled with your understanding of animation timing, will continue to test your new-found skills.
To fully understand how these operate as separate principles, one must become aware of this relationship. Follow-through and drag describe separate types of action 35 36 Animation: The Mechanics of Motion and while they are not the same, they do affect each other and occur within the same movements. What is overlapping action? Animating the motion of inorganic objects can be tricky, but animating living things is far more complex.
Generally, the movement of the different parts of a living creature do not occur at the same time; things start, move and stop at different points and move at different rates. In order to achieve this lifelike action it is necessary to create time lags between these separate actions making the movement of the individual elements overlap.
We call this overlapping action. Overlapping action describes these variable actions within an object and how some elements of an object start, continue and end their movement in relation to others. An object, even one with a low degree of complexity, will demonstrate varying levels of dynamics throughout its structure during its natural motion.
The separate parts of things nearly always move at different times and at different speeds. Animating a character as complex as a horse, for example, will by necessity demand a high degree of variable dynamic actions due to the nature of its physiognomy and the complexity of its mode of locomotion.
A fish, on the other hand, may demonstrate far more simplistic actions. You will find that the main area of action in a human during locomotion often comes from the hips and that other parts of the body will follow. Staggered timing It is important to remember that the separate things that make up a character — head, body, arms, hips, hair, etc.
Animators are usually after achieving a lifelike action, even in abstract cartoon animation, and only machinery or perhaps Basic principles 37 Figure 1.
This will give you phrasing of the action. In the same way as the separate elements should not start and end their actions at the same time, they should not wait until other elements have come to rest before they in their turn begin their movement. This would give the overall animation a very unnaturally stiff action, a sort of stop—start quality.
Using pose-to-pose animation or key-frame animation, it is possible to break down a complex action into separate, more easily managed stages, which simplifies the process of making overlapping action. As animators begin their work, they will add layer upon layer of animation timings to the separate elements of the action. We can break this process down into primary, secondary and tertiary actions according to how they affect and are affected by the overall movement.
Primary actions Primary actions are those actions that are central to any given movement. In such an animation, the action will be driven by the leg and hip movement of a walking figure. All other actions, such as swinging arms, bobbing head, 38 Animation: The Mechanics of Motion Figure 1.
The primary action of the man walking while carrying a box is seen to be the movement within the legs; this continues though the secondary action of the arm swing is no longer there. Imagine a man walking while carrying a large cardboard box. The arms will no longer swing, though the walk itself will not be affected in any fundamental way.
In a walk the animator may begin with the legs and hips as primary action before moving on to animating the arm swings and movement in the upper torso.
Secondary actions Once primary action is completed, the animator may go on to animate the secondary actions that assist the primary actions. These movements are those that are usually linked to primary actions and make for more efficient movements, such as the Basic principles 39 Figure 1. However, it is perfectly possible to execute a run with little or no arm movement, though such a restricted action will appear, in most cases, unnatural.
The arms and hands could be animated separately to produce a particular gesture or movement. Tertiary actions Tertiary actions are actions that are simply the result of the primary and secondary actions, and are often the movement of those things that are simply attached to the main figure.
These types of actions are often used for appendages or costume details, and are perhaps best exemplified by such 40 Animation: The Mechanics of Motion Figure 1. The cloak will obviously be subject to the natural laws of physics and the exact nature of the movement will also be determined by the material the cloak is made from. More substantial material such as a heavy woven cloth will move very differently from lighter fabric such as cotton or silk.
Such actions are usually of little consequence to the movement of the figure. If the tertiary action is associated with additional elements such as a costume or a carried object, the weight and size of these elements may begin to determine the primary and secondary actions. For example, a heavy full-length cloak may result in the figure leaning forward slightly during a walk, while a figure walking with a large heavy sword on their hip may compensate for the weight by leaning slightly to one side.
Lip synchronization often, though not always, falls into this category. This aspect of animation is covered more fully within the section covering sound synchronization. It is important to have an understanding of these different types of action and how they interact in order to create a believable whole within any movement.
For animators to be effective and efficient in their work, it is necessary for them to prioritize their efforts and the categorization of actions can help in this. Whenever possible, animators should initially concentrate their efforts on the primary action, and only when that is satisfactory should they go on to add secondary and tertiary actions and any additional refinements. This is one area where the art of Basic principles 3D stop-frame animation is fundamentally distinct from either 2D classical or computer animation.
Model animators do not have the luxury of creating layers of animation one over another; everything, including lip-sync, must be executed at the same time. In this regard, model animation has much in common with puppet plays. Model animation is more like a live performance than the constructed actions associated with other forms of animation. One could compare stop-frame animation to the complexity of a live performance by a symphony orchestra.
In order to make a coherent performance it is necessary for every instrument to be played in perfect synchronization and harmony. The rate and order in which a movement begins are dependent upon the inertia within a figure or part of a figure, the momentum a figure gains once an action is undertaken, and the use of muscles and flexible joints throughout the figure.
The next movement will come from the hips as the bent legs begin to straighten out. The arms will straighten out in order to add thrust to the upward movement. The whole upper section of the body will begin to rise and move forward as the legs continue to straighten.
During this process the arms will be readjusted to aid balance, bending at the shoulders, elbows and wrists. As the figure is almost upright, the torso will regain its vertical aspect, the neck adjusting for the continued balance of the head.
A short step may be taken, one leg lifted slightly and moved forward in an attempt to balance the figure as it takes into account the momentum the forward motion has built up. Basic principles On the face of it, animating both of these actions appears to be fairly straightforward. However, we can see that it involves a number of individual actions, each demonstrating its separate and distinct dynamics and timings, potentially creating animation as complex as a performance by a symphonic orchestra.
Of themselves, the separate movements are reasonably uncomplicated, and if we approach the animation in a sensible and organized way, we can achieve a continuous naturalistic action throughout the sequence, changing as the nature or the direction of the movement changes.
Animation is just doing a lot of simple things — one at a time! A lot of really simple things strung together doing one part at a time in a sensible order.
Richard Williams What is follow-through? Follow-through actions are those actions that continue after the main instigating factor behind the motion has either come to rest, changed direction or ceased to influence other elements of the object or figure. Once a moving figure has come to a halt, certain aspects of the figure such as the arms or any loose items such as clothing may sway forwards and then backwards at a decreasing rate until they themselves finally come to rest.
Consider for a moment the action of animals in motion. The tails of many animals are subject to follow-through action; the floppier the tail, the more likely it is that the follow-through action will be greater.
Follow-through action is also clearly evident in such things as clothing, dresses, coats, and in long hair. Costume Overlapping action is also clearly evident in cloth, drapery and other appendages of costume design. The upward movement of the head will result in the ears moving upwards also. As the head starts to move in a downward direction the tips of the ears will continue for a short while on their upward journey.
The action will follow through. As the head reaches the lowest part of its action, all parts of the ears will now be moving downwards, following the action of the head. Hart mechanism. Scott Russell mechanism.
The link OQ and the fixed link are equal in length. Therefore the point P traces out a straight path normal to AR. The best position for O may be found by making use of the instantaneous centre of QR. A ratchet and Pawl mechanism consists of a ratchet wheel 2 and a pawl 3 as shown in the figure.
When the lever 4 carrying pawl is raised, the ratchet wheel rotates in the counter clock wise direction driven by pawl. As the pawl lever is lowered the pawl slides over the ratchet teeth. One more pawl 5 is used to prevent the ratchet from reversing. Ratchets are used in feed mechanisms, lifting jacks, clocks, watches and counting devices. It consists of a driving wheel D carrying a pin P which engages in a slot of follower F as shown in figure. During one quarter revolution of the driving plate, the Pin and follower remain in contact and hence the follower is turned by one quarter of a turn.
During the remaining time of one revolution of the driver, the follower remains in rest locked in position by the circular arc. Hence this mechanism finds its use in copying devices such as engraving or profiling machines. This is a simple figure of a Pantograph. The links are pin jointed at A, B, C and D. Link BA is extended to fixed pin O. Q is a point on the link AD. Then it can be shown that the points P and Q always move parallel and similar to each other over any path straight or curved.
Their motions will be proportional to their distance from the fixed point. Let ABCD be the initial position. Suppose if point Q moves to Q1 , then all the links and the joints will move to the new positions such as A moves to A1 , B moves to Q1 , C moves to Q1 , D moves to D1 and P to P1 and the new configuration of the mechanism is shown by dotted lines. The ratio of the crank movement to the slider movement approaching infinity is proportional to the mechanical advantage.
This is the principle used in toggle mechanism. A toggle mechanism is used when large forces act through a short distance is required. The figure below shows a toggle mechanism.
Links CD and CE are of same length. This can also be used for shaft with angular misalignment where flexible coupling does not serve the purpose. It is commonly known as Universal joint. In Europe it is called as Cardan joint. This is done by actually drawing the mechanism to a scale or by calculations.
Therefore for different value of the corresponding value of and are tabulated. In an Ackermann steering gear mechanism, the instantaneous centre I does not lie on the axis of the rear axle but on a line parallel to the rear axle axis at an approximate distance of 0.
In all other positions pure rolling is not obtainable. By varying the angle of the crank piece it can be used to change the angle of movement from 1 degree to degrees. The Geneva stop is used to provide intermittent motion, the orange wheel turns continuously, the dark blue pin then turns the blue cross quarter of a turn for each revolution of the drive wheel. The crescent shaped cut out in dark orange section lets the points of the cross past, then locks the wheel in place when it is stationary.
Notice that the handle traces out an ellipse rather than a circle. A similar mechanism is used in ellipse drawing tools. Notice how the speed of the piston changes. The piston starts from one end, and increases its speed. It reaches maximum speed in the middle of its travel then gradually slows down until it reaches the end of its travel. The rack is the flat, toothed part, the pinion is the gear.
Rack and pinion can convert from rotary to linear of from linear to rotary. The diameter of the gear determines the speed that the rack moves as the pinion turns. Rack and pinions are commonly used in the steering system of cars to convert the rotary motion of the steering wheel to the side to side motion in the wheels. Rack and pinion gears give a positive motion especially compared to the friction drive of a wheel in tarmac.
In the rack and pinion railway a central rack between the two rails engages with a pinion on the engine allowing the train to be pulled up very steep slopes. The part used to move the ratchet is known as the pawl. The ratchet can be used as a way of gearing down motion. By its nature motion created by a ratchet is intermittent. By using two pawls simultaneously this intermittent effect can be almost, but not quite, removed. Ratchets are also used to ensure that motion only occurs in only one direction, useful for winding gear which must not be allowed to drop.
Ratchets are also used in the freewheel mechanism of a bicycle. For each complete turn of the worm shaft the gear shaft advances only one tooth of the gear. In this case, with a twelve tooth gear, the speed is reduced by a factor of twelve. Also, the axis of rotation is turned by 90 degrees. Register for a free. Animator Cube is a multi-axis cage for stop-motion animation and visual effects. Combining it with Dragonframe DMC and Dragonframe software, it lets you program camera moves with almost no.
A bulldog clip is a device for temporarily but firmly binding sheets of paper together. It consists of a rectangular sheet of springy steel curved into a cylinder, with two flat steel strips inserted to form combined handles and jaws. Given that motion graphics and visual effects artists creating virtual worlds are so closely related in the professional practice it is no surprise that designers are embracing filmic storytelling in disciplines such as architecture, interactive design and product design.
So when we think of digital animation tools with the purpose of creating narrative films, we usually deal with metaphors representing traditional techniques. For that reason and others such as the immediate results obtained in CGI animation, television designers widely adopted these new tools at an early stage of development.
These systems created by engineers who rarely received feedback from designers and artists during their development, and for a long period where only accessible to technicians with limited or no artistic background. A tentative classification As definitions by themselves may not give a clear picture of the differences between Animation and motion graphics, one option was to tabulate comparative attributes of both fields, many of which have been exaggerated for argument sake and may be easily refuted, however may help us create a framework for discussion.
Comparative attributes of Motion Graphics and Animation As the task of defining motion graphics may still be unconcluded at this point, one may resort to understand and define motion graphics as an independent discipline by tracing its history.
A Brief History Motion graphics or typographical animation has been used by the film and television industry for decades in order to present and promote movies and TV shows, while this industry has adopted traditional animation techniques in its arsenal of tools, it is also known for pioneer research and development of new techniques, mainly in computer graphics.
In the first half of the 20th century the field was not considered a subject itself, being identified with experimental work of artists, animators and programmers. There is no doubt that Saul Bass is the most influential designer pioneering the use of moving graphics applied to film titles, his work still inspires generation after generation, consolidating the art of the title sequence as part of the film culture.
Binder is known for the opening credits for James Bond movies, landmark icons of film history. Titles sequences can be considered an art form in itself. Technical advances in the s such as motion control and optical effects took the art of film graphics to a new level. The Quantel Paintbox became the landmark platform for the production of television graphics in the s, it was a very expensive system, so with the exception of music videos and advertising, there was a lack of creativity in the period, especially in network TV.
British designer Martin Lambie Nairn, was a notable exception, and took broadcast design profession to a new level. His work for the BBC, Channel 4 Lambie Nairn, , and many other networks was conceptual and highly well executed, raising the bar for a whole generation. One of the most important changes came with the introduction of Cable TV, opening the doors of the stations to a new generation of designer. In the s desktop video systems revolutionized the market.
Today motion graphics has established itself as a field of work, its boundaries with animation, special effects and user interface design are loose, while dialoguing with all these fields, and it has consolidated as a design discipline that has become more ubiquitous as we see motion involved in electronic displays surrounding us.
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