https://lottie4j.com/tags/ai/Hugoen-USThu, 02 Jul 2026 00:00:00 +0000https://lottie4j.com/status/2026/20260702-closing-visual-gap/Thu, 02 Jul 2026 00:00:00 +0000https://lottie4j.com/status/2026/20260702-closing-visual-gap/2026-07-02 by Frank Delporte Closing the Visual Gap with the Official Lottie Webplayer A Lottie library is only as good as its output looks. If an animation renders differently in Lottie4J than it does in the official web player, that’s a bug, even when no exception is thrown and the code looks correct. Within the fxfileviewer, there is an app to visually compare the result of the JavaFX player and a webview using the official JavaScript player. Problem is that I was using the JavaFX Web component for this and this doesn’t fully support the latest/best version of this player. Based on this app for manual checks, I also created a unit test which is able to loop over a set of files and compare the differences to make sure changes in the code don’t break the existing renderer. But I kept struggling with the same test file interactive_mood_selector_ui.json which didn’t render correctly, both in the JavaFX view and my web-based view to compare it with.