Weight paint : Paint brush : Add parameter to the brush falloff

Falloff shape can be sphere or projected. Both are likely to affect a surface behind the visible surface, as it affects all vertices if the influence of the brush. Even for the sphere shape, any vertex behind the face in front (the one we see and point at with the cursor) is affected as long as it is close enough.

So when I paint the wing of a bird (a dinosaur in fact), I also paint the body as long as I choose a size of the brush big enough, of a scale of the view small enough.

It would be great to have a new parameter which default is 1 to multiply the distance towards. Or add a trim towards distance, and if this distance could be absolute and not in pixel would be marvelous.

Or both parameters !

Imagine painting a set of feathers one on top of each other, but separated, and you would like to weight paint the first one without painting the others.

It would also be great to have a selector to set the brush in absolute size, not only in pixel.