[bobbylarrybobby]

On iOS, you schedule animations (and all UI updates, period) on the main thread. iOS is then free to make those happen in a non blocking way. iOS dev 101 is “don't do long synchronous work on the main thread because your app will lose the ability to update its UI for the duration”

[meindnoch]

Lottie was running the animations on the main thread, via CADisplayLink.

By the way, you can “schedule” animations from any thread if you use CoreAnimation directly. CALayers are thread-safe. You just need to manage the CATransaction yourself.

Also, trying to explain “iOS 101” to Marcel Weiher is a bit rich…

[ricardobeat]

Scheduling an animation from the main thread is very different from running the animation on the main thread:

> Once per frame, Lottie would execute code on the main thread to advance the progress of the animation and re-render its content

[vijaybritto]

It's common for all client apps to not block the main thread be it iOS, Android or Web