I noticed that a lot of models for games with mid poly models seem to have their vertices' weight value have very specific values, for example: 0.1, 0.2, 0.3, 0.4 etc. When they have in betweens of those, it's also specific numbers such as 0.125 or 0.15 Never things such as 0.48739 which I get when regularly weight painting for example. I presume the specific values are to save up on file size space in some manner.
What I've always wondered was how this effect is achievable?