Interpolation, easing, & smoothing

Lesson info

Lesson info

In the past, artists would have to animate frame-by-frame. Enter: the computer. There are three major aspects to digital animation that can apply to all sorts of motion graphics we can create today — (1) interpolation: automatically creating motion between frames, (2) easing: controlling how linear or softened this motion appears, and (3) smoothing: adding a damping effect which smooths an animation as it approaches its trigger destination.

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As we know, when we have Point A and Point B, and we're looking to animate a movement, we can't just cut. Visually, we're looking for additional frames in between so the motion is smoothed out.

In modern animation, many artists use something called "technology" to create the frames in between Point A and Point B. That process — creating those in-between frames? Of course, that's interpolation. We're interpolating the frames in between these two points.

So on the animation timeline here, we’re only setting the starting point and the ending point. We start here, and we end there. If we add another point in between? (Of course in an animation we can call these keyframes, or actions.) But we can click right in the timeline and add as many points as we want. And everything in between is interpolated for us.

That’s interpolation. What about easing?

Here’s a car. And we’ll animate it using linear motion. Linear motion takes a direct path from Point A to Point B.

With easing, we’re taking, in this case, distance (or movement) and time, and changing what would be graphed as linear and making it something else. Here’s that same animation with easing applied. And there are a ton of easing options — they can apply to movement, opacity, background color, rotation — anything. And you can affect that easing right here in the in the Interactions panel.

That’s easing. Finally, let’s cover damping (or smoothing). This is really helpful for animations that occur on a scroll or on a changing mouse position. Here, we’re trying to create a parallax depth effect as we scroll. And on a trackpad, which is what we’re looking at now, things look great. But what about moving abruptly? Quick changes. Or what if we’re using a scroll wheel that jumps quickly? The animation isn’t necessarily obvious. It’s clunky. And that’s because the position change (and the animation) is occurring at exactly the same time.

Enter: damping. We do this by adding a bit of smoothing to the trigger. So now if we scroll, even if it’s abrupt, we’re smoothing out the animation as it approaches the actual scroll position (it catches up). And we can see it functions as a hysteresis — kind of a lag which is taking into account our previous scroll positions, and smoothing everything out. A higher smoothing number? The more we increase this? That increases the damping effect. Lower smoothing numbers? Or even 0% smoothing? Everything is animating — it’s reacting — in real-time.

Now. This doesn’t override any easing settings we’ve created inside our animation. It only softens and smooths out the approaching velocity towards the correct position on the timeline.

So. We have interpolation, which is how with any two points, we automatically fill in the in-between values to create an animation. We have easing, which is how we can control the distribution of those values if we want something non-linear. And we have smoothing. Adjusting how smoothly animations catch up with triggers like scroll position or mouse position.