Bitmapflow is a new, open source animation tool created in the Godot game engine, that is used to create new frames of animation from a sprite sequence. These “inbetween” frames are created using one of two algorithms, SimpleFLOW and DenseRLOF. Bitmapflow joins a growing list of tools, such as Pixelorama and Material Maker, that are created using the Godot game engine.
Bitmapflow is described as:
Bitmapflow is a tool to help you generate inbetweens for animated sprites. In other words, it makes your animations smoother. It uses optical flow to try to guess how the pixels move between frames, and blends them accordingly. The results are far from perfect, and probably require some editing by hand afterwards, but sometimes it can produce decent results.
It supports loading and saving animated gifs, spritesheets and individual frames.
Bitmapflow is available for download on Windows platforms on itch right here. Since it is a Godot application, it should also work on other Godot supported platforms (Linux, Windows, maybe Raspberry Pi) if built from source. The source code is hosted on GitHub with the source code released under the MIT source license. Please note Windows users the the Visual Studio Redistributable Runtime needs to be installed for Bitmapflow to work, there is a pretty good chance you already have this installed, but if you run into trouble, this is the most likely cause.
You can learn more about and see Bitmapflow in action in the video below.