Famous American animator Bard Bird once said, “Animation is about creating the illusion of life. And you can’t create it if you don’t have one”.

The wittiness of the remark aside, it is true that animation is essentially an illusion that our visual system feeds us. If you think about it for a second, you can see that there is nothing too special

about animation other than the fact that we’re being fooled (or, more accurately, our brains are being fooled) into seeing something that isn’t really there. We might think that the animated cartoons are moving, but that is not entirely true.

Animation is an illusion that is made possible because of certain peculiarities of the workings of our eye-brain system. The other part of Bird’s quote, equating not having a life with not being able to animate is only true if you want to make realistic, high-quality animation that mimics real-life movements as precisely as possible. If, however, you’re just beginning your journey into the world of animation, you can get by just fine even without a life, so to speak.

Why is animation an illusion?

Well, animation, in simple terms, is a string of static pictures strung together to be played back at a certain speed (displaying 12-16 or more images in each second) although our brain doesn’t see them as separate static pictures. For the brain to be fully fooled into believing that smooth motion is happening (when in reality the static images are changing at a rapid-fire speed), there are some other technicalities that need to be addressed. For example, the speed at which the light from a projector apparatus is interrupted when changing the pictures, has to be high enough as well (this is assuming we are projecting the stills onto a screen).

How are objects animated?

There are some established methods for animating objects. One of the methods that you might already be familiar with is called flip-book animation in which you take a small strong notebook and draw a figure on each page with slight changes from one page to the next. And when you flip the pages at a high speed, you see the figure moving. Again, for somewhat convincing motion, the changes to the figure from one page to the next must be small (sometimes very, very small). However, this is a very time-consuming method and is not very efficient.

Let’s move on and see what else is there for us.

Flat animation

This used to be a very popular method among animators and it was used in almost all of the very old animated cartoons. Flat animation is when you draw a character like you draw it in flip-book animation, but instead of flipping through the pages, you project the ‘pages’ (the drawings) at a screen using a projector apparatus. Animators use what, in the field, is called layering to add intricately drawn, detailed and baroque background to a foreground of sketchy (non-elaborately drawn) fore characters. The characters lack details because the animators have to draw a very large number of pictures of the same character, and if the character had details, it’d be pretty hard for the animators to draw more than a couple sketches in a limited time.

Often times, in flat animation, the animator makes cycles of a character e.g. a set of frames/pictures showing how the character walks while standing straight, and these pictures can be repeated in a cycle to show the character walking. After that, whenever the character needs to be shown walking, the cycles can be essentially copy-pasted without repeating all the work.

Consider this: You can have a very detailed supermarket with aisles and items on the shelves, and you can just ‘paste’ your character there and bam! You get a walking character in a supermarket. Now suppose that after shopping in the market, the character goes home, and must be shown crossing a busy street. With cycles and layering, this is an easy task for the animator.

A very experienced animator usually draws what are called keyframes (starting and ending frames in an animation), and a team of junior animators draws the frames between the start and the end frames. This is called ‘inbetweening’ (yep, it sounds funny, but it’s a real word!). Time must be put into getting it right, or else the movements might seem jerky.

Stop-motion animation

This is a more intuitive way of animation in which we create a real-life model of a character using actual physical materials (e.g. metal, clay, wood, screws, etc), which also means that it has real moveable parts. That is, you can move the character’s arms, legs, head and sometimes even eyes (supposing that the eyes are not painted and are made of marbles or some similar material).

Huge efforts are put in to create a 3D real-life model that is both easily movable and looks good, while satisfying other requirements of the character in a given scenario. In stop-motion animation, if we want to change the character’s hair, we can just give the character a new toupee. Don’t like the character’s footwear? Change it! Don’t like the character’s clothes? Change them! With hand-drawn flat animations, we’d have to redraw the character if we wanted to change its clothes or shoes. And that can be very time-consuming.

Now, you must be thinking: how do we actually animate the model? We do that by moving the character bit by bit, and then taking a snapshot or picture of that particular pose, and then moving the character again and taking a snapshot. This process repeats until we have all the frames that we need to create the animation that we want.

So far we have covered the two most common methods animation methods, and many of the animations that you have seen in your childhood were probably made using one or the other. But is that all there is to animation? Is there another method that can allow you to make animations easily? Aren’t you wondering how all those hyper-cool Pixar and Disney movies are made?

The answer to all these questions is: there is another method that employs digital technology (or computers) to make the process a bit easier.

Computer animation

As it happened with many other fields that were revolutionised by the advent of computers, animation also became easier to execute. This is because with a computer, we can draw a virtual 3D stop-motion model and easily modify its mesh and geometry, and add new features. We can even ‘tell’ the computer to make use of the realistic properties of a certain element (e.g. wood) to make the model more appropriate in our context.

Similarly, if we throw some water on a wooden surface, it’d definitely look very different than if the surface had been metal. With computer-based rendering, the software takes care of that. And it doesn’t stop there: We can go one step further and create our own custom textures and materials that behave in a specific way that we have defined.

Once we have a 3D model of our character, our job then is to add bones, that is, digital bones, to our model so that we can move it from its various pivot points (joints). This is called rigging (creating a digital skeletal structure that mimics the biological skeletal structure of humans or the thing that we’re creating). After creating a rig, we must ‘bind’ it to our model so that when the rig handles are rotated or moved, the model moves and deforms in an appropriate way.

One of the things that the computer software takes care of is ‘inbetweening’. The computer can calculate what the frames between ‘keyframes’ (first and last frames) need to look like if smooth motion is to be conveyed. We don’t have to draw the frames manually or even move the model frame by frame and manually take pictures of it. The computer takes care of it all. Finding the rotation, position and other properties for the frames, however, involves mathematical calculations.

There is also something called painting weights. It is the process of specifying what areas and by how much they are affected/deformed when a rig handle is rotated/moved. It involves some complexities that are beyond what we’ll be discussing, but just to give an example: If you close your forearm, it creations tension which causes the muscles on your arm to move in a specific fashion, right? If the forearm of our model is closed, it should have a realistic effect on the muscles of our model. And this ‘closing’ should not have undue side effects on the wrist or other nearby muscles. As noted, this is a pretty complex process, and takes a great amount of practice. I should know because I tried painting skin weights, and it was no easy job!

But tell me, has this introduction to the world of animation piqued your interest? Would you like to know in-depth how those breath-taking Pixar movies are made? If so, you are in luck because a few years ago Pixar partnered with the Khan Academy to create a free online learning series called ‘Pixar in a Box’ that shows in great detail how animated movies are made at Pixar. The whole creation cycle from the initial storyboarding to the final movie is explored in the course. The website makes it is possible to jump from the contents to a topic of your liking, or you can just follow along the course in a linear fashion (which is what I’d recommend).

This series will give you all sorts of information about interpolation, rigging, simulation and what not. What are you waiting for? Jump right in at https://www.khanacademy.org/partner-content/pixar/

Published in Dawn, Young World, July 18th, 2020