Book Image

UI Animations with Lottie and After Effects

By : Mireia Alegre Ruiz, Emilio Rodriguez Martinez
Book Image

UI Animations with Lottie and After Effects

By: Mireia Alegre Ruiz, Emilio Rodriguez Martinez

Overview of this book

Lottie is a small and scalable JSON-based animation file. LottieFiles is the platform where Lottie animations can be uploaded, tested, and shared. By combining the LottieFiles plugin and the LottieFiles platform, you’ll be able to create stunning animations that are easy to integrate in any device. You’ll also see how to use the Bodymovin plugin in After Effects to export your animation to a JSON file. The book starts by giving you an overview of Lottie and LottieFiles. As you keep reading, you’ll understand the entire Lottie ecosystem and get hands-on with classic 2D animation principles. You’ll also get a step-by-step guided tour to ideate, sketch for storytelling, design an icon that will fulfill the needs and expectations of users based on UX, and finally animate it in Adobe After Effects. This will help you get familiar with the After Effects environment, work with vector shape layers, create and modify keyframes using layer properties, explore path and mask features, and adjust timing easily to create professional-looking animations. By the end of this animation book, you’ll be able to create and export your own Lottie animations using After Effects and implement them in mobile apps using React Native. You’ll also have an understanding of 2D animation best practices and principles that you can apply in your own projects.
Table of Contents (16 chapters)
1
Part 1 - Building a Foundation With After Effects and LottieFiles
5
Part 2 - Cracking Lottie Animations
9
Part 3 - Adding Your Lottie Animations Into Mobile Apps

Chapter 10: How To Nail It: Controlling Your Animation

At this point, we have a fully functional animation in our React Native app that starts playing as a loop when it is mounted and stops when unmounted. But what if we want to control the playback of the animation? Let's give an example: we need to display the animation of a loading bar while we sequentially download five different files into our app. The loading bar will show the progress of the downloading files by filling itself (20% more each time a file is downloaded), resulting in a fully filled bar once those five files have been downloaded.

Figure 10.1 – Animated loading bar used as an example

In this case, we need to control the animation, updating it every time a file has been fully downloaded and stopping it while the next download is in progress.

To explain how this process works in lottie-react-native, we will review two different alternatives: the declarative and the imperative...