The Skins workflow that the sample Mix-And-Match code relies on assumes you want to use whatever your skeleton specifies, so if you set the setup pose to have that attachment, or no attachment, it will follow that. In that case, the empty slot would be empty whenever you set it to be empty in your skeleton and animation in the Spine editor.
If you use SetAttachment, you have to make nothing about the skeleton or its animations keys that slot, or else your changes will be overridden, and you would likely need to call SetAttachment every frame.
For RegionAttachments, offset can be set by setting its X
, Y
, and Rotation
properties, then calling regionAttachment.UpdateOffset()
to apply your changes.