How to do manual Weight Paint?

So I’m trying to do my weight paint manually cause the auto one is terrible and I’m having difficulty with it. I’ve started it but how do I link my manual weight paint to the model? I went into pose mode and then selected my mesh then i enetered weight paint, I just need to link it. Also when I was subtracting the weight paint on the auto version the ones that werent painted for that bone were still being affected by its motion, any idea why?


“Auto version”?

There’s no need to link anything, other than to create an armature modifier for your mesh. An armature modifier reads your vertex weights and uses them to deform based on the transformations of bones with the same names as the vertex groups. When you’re weight painting, what you’re doing is editing vertex groups.

A typical problem when weight painting is that adding weights to one bone, if unnormalized, won’t subtract weights from another. But based on you subtracting, that shouldn’t be an issue. I mean, they won’t add to any other bone, but they shouldn’t deform with the bone at 0 weight. If you have a vertex with weights of 0 to some bone, it shouldn’t be deformed by that bone (unless you are using bone envelopes, I suppose.)

If you want to link a file that has verts with 0 weight being affected by that bone, I’d take a look at it.

So I was moving the forearm and it started to deform the leg area even though there are no paints around that area. And when I said the “auto version” I just mean the auto weight paint.

I doubt that that part of the thigh actually has zero weights to the arm. More likely is that it has very, very low weights, but no other weights, so that’s getting normalized to 1. (0.0000001/[0.0000001+0]=1.)

Or, 1-ish.

To check out a vertex’s weights more carefully, switch to vertex mode in weight paint (v in 2.79 defaults), then select the weird vertex. Look on the properties shelf sidebar under vertex groups.

You might have to select those vertices on the leg, and then unlink/deselect them with the vertex group menu. I think this is done with edit mode? It’s been awhile sense I had to edit something like this. That was how I fixed the problems. Adding the vertices is easy, using the painting. There is an option in the painting to show unselected as black. This will reveal your problem.