Help needed to understand normalize weight paint groups

Hi all,

Was trying to weight paint an object and I didn’t understand why it moved the way it did, until I found out about normalize. Once I normalized all groups the weird moving area was all-red, which made sense. BUT. Now I dug into normalization to figure out how it works. And there are some things I don’t understand.

I have an object with 2 bones. All vertices have weight 1.0 on both bones. If I move a bone it looks right, it’s affected equally by both bones, as expected.

Now I go to weight paint and under Weight Tools select Normalize All. I go back to edit mode and look under the N-panel. My randomly selected vertex will have weight 1.0 on one bone, and 0.0 on the other bone. I had expected 0.5 on both bones, since the normalize description says they will keep their relative weight. This goes for most vertices, though a few have something like 0.994/0.006 or even 1.0/0.0000006. With this behaviour I don’t understand how to use normalize all, since now the object will react completely different to bone-adjustments. Can someone explain this behaviour?

Also. If I choose normalize (not normalize all) in Weight Paint, nothing happens to the group. If I instead use the Normalize in Edit mode under Vertex Weights, then I get the expected 0.5 weight on both vertices.

I posted a version of the same question here:

There’s a gif that shows what I’m doing as well, couldn’t add the gif to this post.

You are keeping the value of the active group. Look in weight paint mode at the operator under all groups. The little check box keeps the active group the same. So you keep it the same and then normalize all groups. Since you only have one other group that is left, it is 100% on the group that is not active.

Thanks a billion. That was so simple. I was so confused and the solution was that simple. Thank you again.

Is it possible to deselect the active group? Or to select multiple groups? Doesn’t seem like the usual ctrl/shift -click methods work out.

If you lock a group in the vertex panel in properties, it won’t normalize. The little lock symbol. You normally use this if you are really happy with the way bones interact and you don’t want to screw it up after your hard work. The ones left will be normalized.

Take a look at to get a good understanding of weight painting. I gave you a link in a series so you may need to skip around to get what you need. One of the best explanation on weight painting a rig.

Thanks for the link. I’ve been looking for something like that, but for some reason never found that series.