A Blender plugin to join a mesh into another one and create a shape key to "hide" it (ie. shrink it to oblivion).
It also creates a vertex group for the original vertices so you can select it easily.
Tested in Blender 3.1.2.
Make a backup of your project to avoid losing any work.
- Add the plugin to Blender
- Open the "Misc" tab
- Select your base mesh (that will have the shape key)
- Select your new mesh (that will be joined to the base mesh and hidden)
- Click "Create"
Note that any armatures will need to be manually joined.