Auto Weights happening automatically and taking a long time are separate from what the OP is talking about. It takes so long because it's generating a high density mesh and apply a sophisticated algorithm to determine intelligent weights. You can use it on a mesh bound to many bones and it should do a decent job. It doesn't take long on a single bone for me, about 2 seconds, mostly just to show the dialog. I'll look at making it faster though, it doesn't need to show the dialog for a single bone.
Anime Studio is doing two things. First, it generates a mesh under the covers. How many vertices it has is anyone's guess, but I'd say it has many. Second, it seems to be using a more sophisticated skinning, maybe quaternion.
You can do something similar in Spine. Probably you guys already know this, but I'll throw out this short video anyway:
VIDEO
Awesome that Auto Weights decided to freak out and assign one wrong vertex weight. :bang:
You can use Generate to quickly create a mesh. Creating hundreds of points may be what you want, eg if not making a mobile game. 🙂 Auto Weights gives you a reasonable starting place for binding bones to the mesh. It deforms fine until you do an extreme bend. Spine uses linear blend skinning which tends to lose volume at extreme bends. However, it is very fast to compute. Spine may implement different skinning math in the future.
