Lottie for iOS (and Android)

Lottie is a mobile library for Android and iOS that parses Adobe After Effects animations exported as json with bodymovin and renders the vector animations natively on mobile and through React Native!

For the first time, designers can create and ship beautiful animations without an engineer painstakingly recreating it by hand. Since the animation is backed by JSON they are extremely small in size but can be large in complexity! Animations can be played, resized, looped, sped up, slowed down, and even interactively scrubbed.

Lottie also supports native UIViewController Transitions out of the box!

Here is just a small sampling of the power of Lottie

![Community](_Gifs/Community 2_3.gif)

Using Lottie

Lottie supports iOS 8 and above. Lottie animations can be loaded from bundled JSON or from a URL

The simplest way to use it is with LAAnimationView:

LAAnimationView *animation = [LAAnimationView animationNamed:@"Lottie"];
[self.view addSubview:animation];
[animation playWithCompletion:^(BOOL animationFinished) {
  // Do Something
}];

Or you can load it programmatically from a NSURL

LAAnimationView *animation = [[LAAnimationView alloc] initWithContentsOfURL:[NSURL URLWithString:URL]];
[self.view addSubview:animation];

Lottie supports the iOS UIViewContentModes aspectFit and aspectFill

You can also set the animation progress interactively.

CGPoint translation = [gesture getTranslationInView:self.view];
CGFloat progress = translation.y / self.view.bounds.size.height;
animationView.animationProgress = progress;

Want to mask arbitrary views to animation layers in a Lottie View? Easy-peasy as long as you know the name of the layer from After Effects

UIView *snapshot = [self.view snapshotViewAfterScreenUpdates:YES];
[lottieAnimation addSubview:snapshot toLayerNamed:@"AfterEffectsLayerName"];

Lottie comes with a UIViewController animation-controller for making custom viewController transitions!

#pragma mark -- View Controller Transitioning

- (id<UIViewControllerAnimatedTransitioning>)animationControllerForPresentedController:(UIViewController *)presented
                                                                  presentingController:(UIViewController *)presenting
                                                                      sourceController:(UIViewController *)source {
  LAAnimationTransitionController *animationController = [[LAAnimationTransitionController alloc] initWithAnimationNamed:@"vcTransition1"
                                                                                                          fromLayerNamed:@"outLayer"
                                                                                                            toLayerNamed:@"inLayer"];
  return animationController;
}

- (id<UIViewControllerAnimatedTransitioning>)animationControllerForDismissedController:(UIViewController *)dismissed {
  LAAnimationTransitionController *animationController = [[LAAnimationTransitionController alloc] initWithAnimationNamed:@"vcTransition2"
                                                                                                          fromLayerNamed:@"outLayer"
                                                                                                            toLayerNamed:@"inLayer"];
  return animationController;
}

If your animation will be frequently reused, LAAnimationView has an built in LRU Caching Strategy.

Swift Support

Lottie works just fine in Swift too! Simply add #import <Lottie/Lottie.h> to your [Swift Bridging Header] (https://developer.apple.com/library/content/documentation/Swift/Conceptual/BuildingCocoaApps/MixandMatch.html)

Then you can import Lottie at the top of your swift class, and use Lottie as follows

let animationView = LAAnimationView.animationNamed("hamburger")
self.view.addSubview(animationView!)
    
animationView?.play(completion: { (finished) in
  // Do Something
})

Supported After Effects Features

Keyframe Interpolation

Linear Interpolation
Bezier Interpolation
Hold Interpolation
Rove Across Time
Spatial Bezier

Solids

Transform Anchor Point
Transform Position
Transform Scale
Transform Rotation
Transform Opacity

Masks

Path
Opacity
Multiple Masks (additive)

Track Mattes

Alpha Matte

Parenting

Multiple Parenting
Nulls

Shape Layers

Anchor Point
Position
Scale
Rotation
Opacity
Path
Group Transforms (Anchor point, position, scale etc)
Rectangle (All properties)
Elipse (All properties)
Multiple paths in one group

Stroke (shape layer)

Stroke Color
Stroke Opacity
Stroke Width
Line Cap
Dashes

Fill (shape layer)

Fill Color
Fill Opacity

Trim Paths (shape layer)

Trim Paths Start
Trim Paths End
Trim Paths Offset

Try it out

Lottie Uses Cocoapods! Get the Cocoapod or clone this repo and try out the Example App After installing the cocoapod into your project import Lottie with #import <Lottie/Lottie.h>

Alternatives

Build animations by hand. Building animations by hand is a huge time commitment for design and engineering across Android and iOS. It's often hard or even impossible to justify spending so much time to get an animation right.
Facebook Keyframes. Keyframes is a wonderful new library from Facebook that they built for reactions. However, Keyframes doesn't support some of Lottie's features such as masks, mattes, trim paths, dash patterns, and more.
Gifs. Gifs are more than double the size of a bodymovin JSON and are rendered at a fixed size that can't be scaled up to match large and high density screens.
Png sequences. Png sequences are even worse than gifs in that their file sizes are often 30-50x the size of the bodymovin json and also can't be scaled up.

Why is it called Lottie?

Lottie is named after a German film director and the foremost pioneer of silhouette animation. Her best known films are The Adventures of Prince Achmed (1926) – the oldest surviving feature-length animated film, preceding Walt Disney's feature-length Snow White and the Seven Dwarfs (1937) by over ten years The art of Lotte Reineger

Contributing

Contributors are more than welcome. Just upload a PR with a description of your changes.

If you would like to add more JSON files feel free to do so!

Issues or feature requests?

File github issues for anything that is unexpectedly broken. If an After Effects file is not working, please attach it to your issue. Debugging without the original file is much more difficult.

Roadmap (In no particular order)

Add support for interactive animated transitions
Add support for parenting programmatically added layers, moving/scaling
Support for the After Effects Trim Paths Offset feature
Animation Syncing
Programmatically alter animations
Animation Breakpoints/Seekpoints
Gradients
LAAnimatedButton
Repeater objects

WeissMaxime/lottie-ios