One of the initial hurdles to becoming a professional animator is handling easing, motion paths and acceleration. The pieces of design that make up the field of "motion design."
Imagine; a layer moves from Point A to Point B, but the path between the Points is full of sharp corners.
Watching the animation, it feels like a chess piece being moved. Lifeless, jagged and abrupt. The pace is steady, the layer starts moving and then stops. It doesn't feel right.
After Effects provides several native methods to "smooth motion," from keyframe interpolation types, to the Smoother panel, or the auto roving keyframes.
In this article we'll investigate the native Adobe solutions, and contrast Motion Studio's Blend tool, which uses a different approach with live expressions and adjustable Effect Controls.
Why Motion Looks Jerky in After Effects
Poor "jerky" or "jittery" positional animation in After Effects is caused by: Spatial (shape of motion path) and/or Temporal (speed of layer on path) Interpolation issues.
Spatial Interpolation: the path shape
When you set a keyframe on Position, if you moved the CTI and Timecode and changed the coordinate, another keyframe will be set. Those two keyframes create a path — visible by the dotted line visible when the Position property of the layer is selected.
By default, After Effects has an application preference for Spatial Interpolation, meaning it will add Bezier Handles to paths in an attempt to create gentle and smooth paths.
PRO-TIP: For simple A-to-B paths, Spatial Interpolation can be a great help. At Mt. Mograph we recommend, changing your Settings > General preference "Default Spatial Interpolation to Linear." The auto-Spatial Interpolation can "misunderstand" the animation goal, and always tries to make paths smooth and gentle. The auto-Bezier handles can become a nightmare for complicated projects and keyframes.
With spatial interpolation — problems can start with adding multiple keyframes, or chaotic positional paths since each keyframe's bezier handles influence the spatial path independently.
A layer moving through 3-4 Points (ex: A, B, C, D) can produce unexpected jerky "bumps", odd overshoots, or sharp direction changes. All of these issues are normally caused and resolved from the Default Settings for Spatial interpolation, resolved using the PRO-TIP above for Linear Interpolation.
You can also right-click a keyframe, or Path Vertex select Keyframe Interpolation and change between four spatial settings:
- Linear (straight lines, sharp corners)
- Bezier (manual handle control)
- Auto-Bezier (auto-smoothed)
- Continuous Bezier (attempts to smooth bezier handles of paths)
PRO-TIP: press (G) to get the Pen tool, then hold (OPT) and when you click and drag Position path vertices, they can become Bezier handles that are unified or, separated. This works great with the Default Linear Interpolation to set accurate coordinates and design the motion path.
Temporal Interpolation: the speed
Even with a perfect positional path set through multiple Points, a layer animation can still feel like a PowerPoint slideshow.
A layer with no Temporal Interpolation (commonly known as Easing) means a layer will move predictably at the same pace along a Path, a constant linear speed, no acceleration, or deceleration.
This style of animation is mechanical, because most things in the real physical world don't start moving instantly and have to build up momentum, or slow down. Think of a car braking, slamming the gas pedal and slamming the brake.
Temporal Interpolation gives life to animated elements.
Adding Easy Easy (F9) or, right-click keyframes > Keyframe Assistant is the "standard" fix to upgrade linear mechanical feeling animations.
Easy Ease basically means objects will build up speed, or slow down gradually, creating a natural feeling.
Working with Temporal interpolations is the true art and skill of an animator and a wildly deep and complex topic. Change the Timeline view to the Graph Editor, change the Graph Type to Speed Graph, and bezier handles can be used to shape the Velocity curve (the speed up and speed down) between keyframes
Keyframes, Easing and the Graph Editor are huge topics we'll share a larger article about in the future.
For even faster changes and fewer clicks, use Motion Studio's Easing tools to skip the right-clicks and sub-menus and harness a suite of improved Graph types and functions.
The native After Effects tools to smooth animated paths
After Effects is packed with tools so that many problems can be approached with a variety of methods. Like, the native Smoother panel (open via Window > Smoother).
The Smoother panel will attempt to reduce keyframes and smooth Spatial and Temporal "issues." (keep in mind, these are mathematical guesses without context to what you are making).
To use Smoother:
- select 2+ keyframes
- set the Tolerance (accuracy)
- click Apply
High Smoother Tolerance values = aggressive smoothing, fewer keyframes and gentle curves BUT less accuracy to the Original path. Imagine, a piece of plastic gradually melting in the heat.
Another helpful native After Effects tool, in the right scenario, to help smooth positional paths is the Roving keyframe.
Roving keyframes set intermediate keyframes that "Rove Across Time" — this lets After Effects recalculate timing, to attempt to produce even/realistic speed across a path.
TIP: Rove literally means "wander" — that should help indicate the reliability of Roving keyframes and accurate animation.
Roving keyframes are great for maintaining a consistent speed/pace, but lock the keyframes out of manual adjustment with the Graph Editor, or more precise Temporal easing.
Both the Smoother panel and Roving keyframes have use cases, but both setups can't be undone easily, lock out further non-auto editing and can create unpredictable changes.
How do I smooth jerky animation in After Effects?
After reviewing the native After Effects methods to smooth keyframes — there are some clear missing functionalities. That's why we built Motion Studio's Blend tool.
The Blend tool smooths ANY keyframed property in one-click with customizable, non-destructive and keyframable controls.
To use Blend:
- select 1 or, more properties across any number of layers with kefyrames
- search and run Blend in Motion Studio
- click Apply, all the configurations are automatically setup
Blend adds an expression to each selected property and custom linked Effect Controls to the layer(s) to control three keyframable parameters:
NOTE: the Blend examples will use the Position property as the most visual transform layer property. Blend can work on ANY property, on any layer type and even effects.
Enable toggles the Blend expression On and Off. Useful for comparing the smoothed result against original keyframes, or to enable/disable at various timecodes.
Smoothness (default: 4) controls how much the keyframe values are "softened." At the default value of 4, motion path corners become more rounded and speed transitions become more gradual. Going back to the analogy about a car slamming on the brakes, this makes the metaphorical pedal less responsive, even if you slammed a foot down.
Higher Smoothness values produce more visible "relaxation" value results. Blend will soften the temporal start and stop of the animation, Smoothness helps determine how the surrounding keyframe data influences points in time.
Precision (default: 25) is a secondary control to refine Smoothness results. Lower precision means a smoother less accurate path (for a Position property*). Higher Precision keeps animation closer to the original keyframes, while still softening transitions.
Because Blend is applied as an expression, the changes are flexible and non-destructive. Adjust or keyframe Smoothness or, Precision in the Effect Controls and the results are instant.
TIP: use the Motion Studio Trash tool to remove/restore original keyframes.
In what animation situations is Blend the most useful?
Blend is a great tool to use on Motion Tracked animation, or properties with tons of keyframes (like a Motion Tracked layer).
Motion Tracking in After Effects will generate a keyframe on every frame in the Timeline. The tracking accuracy can be "too" sensitive — and data can produce jittering (non-technical term for tiny inconsistent value variations and drifting) on playback.
Using the Blend tool on a Motion tracked layer with a high Smootheness Value and a larger precision value will keep the tracked path accurate and also work to remove the jitters.
Manually animated properties can also benefit from Blend, even when they already have Easy Ease keyframes, and will soften any subtle value bumps.
Blend is non-destructive, flexible and keyframable, with separate Effect Controls for each property to adjust Blend intensity independently.
Common Questions About Smoothing Animation in After Effects
What's the difference between Spatial and Temporal smoothing?
Spatial = space Temporal = time
Spatial smoothing will change a motion path (the line a layer follows from Point A to Point B). Temporal smoothing changes the speed the layer travels the motion path.
Blend affects keyframe values through an expression, which can smooth and process both the Path shape (spatial) and speed transitions in one unified operation.
How do I fix motion tracking drift in After Effects?
The native After Effects method to fix motion tracking issues is to use the Smoother panel and find a Tolerance that will remove jittering, while (hopefully) maintaining the tracked layer accuracy.
Blend is the second solution that does not delete or modify keyframes. Blend applies an expression that can be adjusted and keyframed — functioning similar to the Smoother with more flexibility.
Should I use Easy Ease or, Blend for the smoothest animation?
Easy Ease and Blend, are similar but solve different workflows. Easy Ease keyframes and Easing allows you to adjust the speed curve between keyframe pairs. Blend smoothes the Motion Path (spatial) AND timing (temporal) at once.
For simple 2-4 keyframe property changes (Point A, B, C [..]) using Easy Ease keyframes with the Graph Editor is a great method. Using the Value Graph and Speed Graph in combination to tailor the precise movement.
For huge keyframe selections, tracked data or generally "mechanical" or jittery translations, Blend is a better fix (and non-destructive and keyframable).
TIP: Motion Studio has a best-in-class Easing Suite, sliders, graphs, libraries and more with modern Graph Types like Cubic that aren't available in After Effects.
Can I use Blend on properties other than Position?
Yes, Blend works on ANY keyframable property that needs to smooth values translations and speed. All transform properties like position, scale, rotation are supported, deep sub-properties, Effect Controls — everything.
Blend is easiest to explain/show with the Position property having a spatial path to demonstrate bezier curves, roughness and improvement.
Does Blend delete or, modify my original keyframes/
No, Blend adds an expression with customizable Effect Controls that does not change or, set keyframes. The Blend expression calculates and smoothes value interpolations in real-time.
Blend is available in Mt. Mograph's Motion Studio, the gold-standard extension for professional animators. Try Motion Studio free for 7 days — no credit card required.