Step Motion is an addon from YONK that brings a real-life stop motion workflow into Blender. It lets you build frame-by-frame animation by creating, duplicating and adding frames while you edit and sculpt, all through easy hotkeys. Version 1.1 adds in-between frames, prompts you to set a frame's position, and stores previously used materials so they return after Finish Step Motion is pressed.
Onion skinning keeps your active frame visible while older frames fade to red and future frames fade to blue, giving an overview as you work. The Step Motion Preview Geometry Node setup shows your animation in real time, and because it instances your frames you can duplicate them to build scenes by offsetting frame speeds and combining multiple animations without putting too much pressure on your machine.
Each time you open Step Motion your frames are covered in a procedural, animated clay-like shader, and the setup works with Will Anderson Jr.'s free Warpy Step Geometry Node setup for a more claymation look. The package includes three assets: the Step Motion Addon, Step Motion Preview and Step Motion Clay. It runs under a GPL license and supports Blender 3.4 through 4.4.