Layers in skin paint mode

Hey everyone!

With so many changes with Blender's UI and improvements in usability I've noticed a minor gap in rigging system and in particular in skin weight painting.

Blender's skin painting tools are pretty simple and alike skin painting in other softwares. But with just a minor improvment can really speed up skin paint workflow and can make it more friendly for user. More than that it makes skinning possible to work in non-destructive way. More or less.

And I'm talking about layers in weight painting.

The concept is simple and it basicly works like layers in any 2d soft, but with only one blending mode. The next layer sums previous layer influences and normilize it, but instead of calculating the average value between all influences, like it does now, the priority is for the top level.

I'll try to concretize it on example.

I have a character and an armature for it. And I parent the character to armature with autoweighted skin. So the basic layer with all bones is created. And it's pretty fine but need some fixes at extreme pose for an arm for example. So instead of fighting with existing weights which can break my lovely autoskin, I create a new layer. I add arm bones to that layer and paint weights on it with no fright that I can break something, 'cause in any second I can turn off this layer or even delete it, keeping my basic layer in safe.

So basic layer influences normilized and equal 1 for every vertex. We add a layer. We add bones to layer. Paint in this layer from 0 to 1 and this layer overwrites basic layer influences respectivly. So if it is 1 - it overwrites completly. If less than one, 0.5 for example, then it shares other 0.5 with layer below. If vertex has influences from several bones on basic layer, so their weights change respectivly. If their parts were equal to 0.8 and 0.2, so the top layer with 0.5 influence make previous layer influences decrease in multiples. So it gonna be 0.4, 0.1. So we want new layer. We add it. And now basic layer and the second one in sum = 1. And new layer influences will change layers below in their parts. And so on.

Jizz. I hope it make any sence. English is not my primary language.

It maybe sounds a lil bit confusing especially in my words, but the truth is this is very powerfull feature for rig artists in part of painting skin. And it's been implemented in ngSkinTool for maya. Yeah, I know, don't make maya from blender, but this is sideaway plugin)) And its very powerful.

I very ask you to pay attention to that problem, because I think the main goal for Blender is animation. And there is no animation without rigging. And skinning characters is pretty much importatnt part of rigging.

I think it will be better to watch ngSkinTool demo, than if I draw some badly pictures. I think it's pretty informative.

vimeo.com/57454734

ngskintools.com/features/