SJ Phaser is a free Blender add-on which creates secondary animation for Armature bones. According to the author, it mimics the workflow of the “Spring Magic” plugin for 3ds Max.
While the product page says that the addon works with Blender 3.2, I tested it with Blender 5.0 and did not notice any issues.
The workflow of SJ Phaser is fairly simple and straightforward.
All settings and functions are found under N-Panel > SJT Tab.
The main parts of the character (body, head, arms, legs, etc.) need to be animated manually.
Once the main animation is in place, select all bones that need secondary animation such as hair, tail, , clothing, breasts, and so on. Set the Start Frame and End Frame (this is the frame range within which the addon will bake the secondary animation).
Set the Delay, Recursion, Strength, and Threshold. Finally press Calculate.
If you want bones with different Properties, you’ll need to Calculate them one by one, changing the selection and properties before each calculation.
Here is a video demonstrating different combinations of Delay and Recursion Properties:
And another video by the addon developer, demonstrating the usage of the addon: