ANIMATION + EFFECT CONTROLS

On this page, we’ll look at a number of simple kinds of animations that you can make by adjusting effect controls or properties in software like Adobe After Effects or Adobe Premiere Pro.

First off, though, let’s try to define a bit of what we mean by the term ‘animation’ in this context.

Broadly, animations are made up of images that appear in quick succession, meant to emulate the movement of subjects in our everyday 3-dimensional reality. Note that sequential images cannot differ greatly from one another, otherwise any realistic motion effect will be lost.

Basically, an animation is a series of images that relatively change over time to emulate movement.

In this way, an animation is very much the same as a motion picture! The blurred line between the two is that a motion picture is created primarily through photographic means (images being captured onto a photographic surface, such as a digital sensor or film), whereas a modern animation is often created digitally, through the use of computer software. 

There are many ways, though, where this distinguishment doesn’t work, or is confusing. A hundred years ago, an animation meant a cartoon, which was hand-drawn and/or featured cut-outs, and was captured photographically. Computers, because they didn’t exist yet, were not a part of the process.

At the other extreme, many modern movies are shot in giant green screen warehouses and have significant visual effects added in post-production. In many ways, the latest Marvel movie is more of an animation than Disney’s Snow White (1937).

With that in mind, the modern media landscape isn’t divided into animations and motion pictures so much as works that fall somewhere on the spectrum between the two. The line between live-action and animation becomes more and more blurred with each new year of films.

For the sake of simplicity, the sort of animation that we are talking about on this page is the kind that is created with computers, using software like Adobe After Effects or Adobe Premiere Pro, by changing properties of effect controls of elements over time. 

PROPERTIES + THEIR VALUES

Before we look at many of the animation properties, we first must establish how most of these values will be measured. Most of the time, properties are measured in pixels, percentages, or degrees. 

PIXELS

As a measurement unit, ‘pixels’ is directly related to the resolution of the frame, canvas, or composition.

For more on what a pixel actually is, check out The Digital Image or Resolution articles.

When a property is measured in pixels, the value is an indication of pixel distance and proximity, either from the edge(s) of the frame, the anchor point, or in relation to another element. These values can go up to any amount, depending on the resolution of the image, sequence, or project. 

The position and anchor point properties are measured in pixels. 

PERCENTAGE

Percentages are almost always out of 100%, or at least that’s the baseline.

The 100% value might be the absolute maximum value or simply the standard reference for size, where going over 100% (200%, etc.) might result in pixelation, depending on the file type or element being edited. More on pixelation below.

Scale and opacity are measured in percentages. 

DEGREES

Degrees is a rotational property, and it’s easiest to relate it to the idea of the clock.

Degrees are a simple integer measurement that go up to 360º before counting as a full rotation, which then is usually represented by a simple 1x (-1x), and so on. This measurement is relative to the rotational properties of a circle.

Rotation and shutter angle (motion blur) are measured in degrees.

KEYFRAMES

Animation is the change of a value over time, right? Well, the way that we set those values is through keyframes.

A keyframe is how you set a property’s value at any point in time. Changing that property’s value at more than one point in time, using keyframes, is how we animate an element with that value.

Basically, a keyframe tells the software that you want those exact values at that specific frame. When you have more than one keyframe with different values, the software adjusts the values between those keyframes to get from one value to the next.

Keyframes appear in various software as diamonds, circles, or arrows, depending on the type of interpolation applied at the keyframe. More on that below.

AXES

To fully understand how to animate an element within the frame, you have to understand a bit of math. (Sorry.)

Many properties can change values along the different axes of the element, and it’s important to know the order of which these axes are presented in effect controls (because they aren’t labeled), and to know which property to edit to get an element to move the way that you want it to. 

In a simple 2-dimensional project, the two axes are the x-axis and the y-axis. In a 3-dimensional animation, there’s also the z-axis. Here’s what they are:

• The x-axis is movement in the left-right direction.

• The y-axis goes up and down, from top-to-bottom. 

• The z-axis goes toward and away.

When properties are displayed, the axes are displayed in alphabetical order: (x, y, z)

POSITION

As a property value, Position describes where an element is in the digital space.

It’s usually in relation to the anchor point (more on that below), but by default can usually be treated as if it’s in relation to the edges of the frame. Position is measured in pixels.

A 2-dimensional element shows position values like (960, 540). In this example, the x-coordinate of the element is 960 pixels to the right of the edge of the frame. The y-coordinate is 540 pixels from the top of the frame. If we were working in a 1920x1080 (Full HD) sequence, the element would be in the center of the frame (if the anchor point value is untouched). 

A 3-dimensional element adds the property of the z-coordinate. The default z-coordinate, 0, is the position where the element is 100% scale in relation to the frame size. Moving elements directly toward or away along the z-axis effectively changes the scale of the image (as long as the element is still directly in line with the camera, anyways).

SCALE

The scale property is a measurement of size in relation to the default or source size of the element. The default size of an element is 100% scale. At this size, the element is proportional to the frame size, according to the sequence settings. 

For example, let’s say we’re working in a 3840x2160 (Ultra HD) sequence, but the element we’re using is only 720 pixels tall. At 100% scale, the element would be ⅓ the height of the overall frame. At 50%, the element would only be ⅙ the height of the frame.

As you adjust the scale, it becomes larger or smaller around the anchor point. More on that below.

We can go past 100% scale, theoretically to whatever scale we so chose, but if we go much over 100%, we run the risk of the element becoming pixelated, which means that the element is being displayed at a larger size than was intended, and the viewer might start to see the edges of pixels in the image, or, more likely, the image might just lose desired detail and sharpness.

Pixelation is a problem when enlarging rasterized, pixel-based images.

Vector images and elements don’t suffer from pixelation, however. These are certain shape elements created in After Effects, Photoshop, and Illustrator. 

Scale properties can be edited in the separate axes, although they are usually locked together by default. By adjusting the scale along the x-axis, we can make the element narrower or wider. By adjusting the scale along the y-axis, the element can be made shorter or taller. 

ROTATION

Rotation allows you to… rotate the element.

If we’re imagining our axes, regular rotation occurs around the z-axis, which again is the vector that goes toward you and away. The element rotates around the anchor point position, so you can imagine the anchor point as your z-axis. 

Personally, I think of my anchor point like a thumb tack, holding my element in one place while the rest of it rotates around the tack.

Rotation is out of 360º, at which point you’ve made a full rotation, and the software will indicate with a 1x or -1x, depending on whether the rotation was clockwise or counterclockwise, respectively.

3-dimensional elements and animations allow for rotation along the x-axis and y-axis as well. 

OPACITY

Opacity is the inverse of transparency. Likewise, opaque is the opposite of transparent.

To start, elements aren’t transparent at all, so 100% opacity is the default amount, meaning the element is totally opaque and not see-through at all.

I’ve long wished that software wouldn’t measure in opacity, but transparency instead.

If I were to ask a random stranger on the street about opacity, they probably wouldn’t really know what I was talking about. Opacity is a term that most people have heard, but don’t know what it means. But that same hypothetical person-on-the-street almost certainly knows what transparency is, so it would be more intuitive for the default amount to be 0% transparency, rather than 100% opacity, in my opinion. 

ANCHOR POINT

Finally, the anchor point.

The anchor point is arguably the least understood effect control, but it’s important! Well, sometimes.

The anchor point is relative to your element, not the sequence, and the position of the anchor point affects the element’s position, scale, and rotation properties.

But what is it? Well, it’s a point that’s a reference for how these other properties behave. 

The position property is entirely relative to where your anchor point is.

The scale property grows and shrinks the element relative to the anchor point’s position. 

The element rotates around the anchor point. This is the part where the anchor point acts like a thumb tack on a board, holding your element in a particular place and allowing the rest of the element to rotate around that point.

You can even have the anchor point outside of your element! At which point, you might imagine an invisible string that attaches your element to the anchor point.

MOTION BLUR

In After Effects, you have the ability to simulate a motion blur effect on your digital elements. You can control this by setting a ‘shutter angle’ amount in your Composition Settings. 

Just like photographic shutter angle, the motion blur is entirely dependent on your frame rate.

Shutter angle is measured in degrees out of 360º, where 360º is the full length of time between frames. 

For example, if you are editing a composition that has a frame rate of 23.976 frames per second - meaning there are ~24 frames, or images, per second - then a 360º shutter angle would give you an equivalent shutter speed of ~1/24th of a second.

A 180º shutter angle, which is half the rotational angle of 360º - and thus half the exposure time and motion blur - would give you an equivalent shutter speed of ~1/48th of a second.

The 180º shutter angle is the conventional ‘default’ shutter angle of motion picture film. This is why dogmatic (closed-minded) filmmakers always say that you need to shoot with a shutter speed of 1/48 or the nearest value, which is usually 1/50.

There are countless reasons why a practical, thoughtful filmmaker would use a different shutter speed than this, but that’s a topic for another day.

For the motion blur effect to work, you have to check the box next to the layer that looks like several circles in sequence. Only by checking this box will After Effects render motion blur effects on that layer. If you don’t check the box, it is the same as having a 0º shutter angle, which is to say there will be no motion blur at all.

INTERPOLATION

If you are just starting out with animations, and you make two keyframes where the element animates from point to point, you might notice that it doesn’t look quite right.

LINEAR INTERPOLATION

What happens by default is that the properties will change in a linear manner, meaning a constant amount until it gets from the first keyframe to the second keyframe. Changes in position result in elements with constant velocity, and so on.

For example, if keyframe A is at (912, 540) and keyframe B is at (1008, 540), the element will travel 96 pixels along the x-coordinate. Now let’s suppose keyframe A is at 1 second timecode, and keyframe B is at 2 second timecode, and we’re working in a 23.976 frames per second composition. The element travels those 96 pixels over the duration of one second. With a normal linear movement, the element will travel at a constant velocity of about 4 pixels per frame, starting exactly at keyframe A and stopping exactly at keyframe B.

Why doesn’t this look good?

Unless you are going for a very specific type of linear movement, you probably want to apply a different form of interpolation to your keyframes.

Cool… but what is interpolation?

A clue is in the word itself.

Inter- means ‘between’, and -pol- means ‘point’, so interpolation is the type of behavior that occurs between points. In this case, the points are the keyframes we’ve made.

As mentioned, the default interpolation behavior is linear, which is denoted by the standard diamond icon when you create a keyframe.

BEZIER INTERPOLATION
(EASY EASE)

Other types of interpolation, most notably bezier (more commonly known as ‘easy ease’), make automatic adjustments to the rate at which a property changes, to factor in the natural forces of acceleration and/or deceleration.

Bezier keyframes are usually denoted by a circle or hourglass-type icon.

The term ‘Bezier’ doesn’t really mean anything. It’s just named after the dude that came up with the Bezier curve, Pierre Bézier.

In short, ‘easy ease’ interpolation has the software apply acceleration and deceleration to an element's movements to make it look more fluid and natural. 

Keep in mind that, while ‘easy ease’ might be the most natural-looking form of interpolation, ‘easy ease’ is not appropriate for every use. Sometimes you’ll have a sequence of keyframes, and you don’t want the element making a pit stop at all of them, but rather you just want the acceleration and deceleration effect to affect the first and last keyframe. 

After Effects gives you great control over the types of interpolation that are applied to keyframes, including the ability to affect spatial and temporal interpolation separately, as well as manually controlling the velocity curves of the keyframes.

JUST THE BEGINNING?

While this seems like it’s just the start of all there is to know about animation, the truth is that more advanced animations are still using these same simple controls, the creators just know how to control these effects to great degree and sophistication.

Practice and patience, Padawans.