Let’s say you want to make spring animated. You add Skin modifier, add two bones and correct their envelopes.
But now there is a pretty serious problem. Here it is:
Real springs don’t work this way, do they?
You can fix it by selecting vertices by six and assigning them same weight, like this:
But this is obviously too much work. Average spring could have about 80-100 groups, and usually there are four of them. Good luck with that!
Thankfully, this task could be easily automated. Here is a superb tool.
But it won’t help you if all your springs is combined into one object. I’ve changed this script a little, now you can set start & end vertice IDs. It’s unfinished and probably buggy, but still very helpful, if you asked me.
UPD: A little how-to-use video: