Skin Painting weights is moving the geometry?


See also

Never actually solved.

So you have Skeleton bones which are not animated.
You have a hand joint 100% controlling the fingers influence (using the skinning method inside out) and when you add influence to the fingers, the geomtry folds up and distorts for no reason. This has nothing to do with it’s weighting being incorrect, because the vertices should not move, and there is no reason why they should.

Maya 2018 btw

So how Maya SHOULD do this, is when you add influence to one bone, it subtracts away from others. Since that bone in my cast is only the hand bone, it can only take influence away from that joint.

So perhaps the weights are incorrect I hear the young student cry out…
but checking in component mode shows you the values of each independent vertex, relative to what it’s assigned too, and it shows the finger is giving 0.2 whilst the hand is correctly at 0.8

This is why this is still an ongoing MAJOR bug with Maya, and one which has never been resolved so far.

Any professional riggers who may have come across this problem here, who found a workaround please?



You can skin two ways though. Using Post or Interactive normalized weights.

I always use post because I can decide where to subtract influence from.

With interactive Maya tries to figure out on its own where to pull white to and from as you paint.
Most people will start with a primary center influence to place all the white on to start. Then this white is slowly removed from the original center influence as each weight is added to different bones.
The reason I hate this mode is because it always seems too buggy for me. It always creates random placing of weights in other layers I never intended. I know people use interactive but I never do.

With Post you can end up with white on all bone influences at all times.
May does not pull white from one layer to apply it to another like in interactive.
If you have a head bone influencing the entire head and then begin to paint the weight for the jaw bone
you will see the Jaw bone move the jaw BUT it won’t be 100%. It will be split between the white in the head bone and the white in the Jaw bone. At this point I begin painting black on the jawbone influence area over the white in the headbone. This is a bit more meticulous in having to keep track what is where BUT it is always predictable behavior for me. So I always use it.

I also like to use the geodesic voxel to start the weight influences and then because the facial rigging I do requires “closest distance” vs “geodesic voxel” I end up finishing the body first with “voxel” and then copy weights to a cloned mesh that has “closest” and paint the face rig in that way.

Its never one solid method for me. I have developed quite a few combo tricks to get exacting results from each tool that you can’t get by just going one direction the entire rigging process.

I’d simply ask if you assign all the weight to one main joint at first?

I assume you are using “interactive” weights, OR maybe you are using “post” and that is why its not pulling influence live?


That’s exactly what I did.
Started from main joint 100% and worked outwards. Every vertice had a correct balance, and there was no reason for this error to happen sadly. I’ve seen other forums with the same question, and yet no one has ever resolved this issue. They either ended themselves or gave up forever :smiley: skinning is the worst job if you don’t use some specialised external package to mainstream autodesk, as it’s one of AD’s weakest features, and always has been. I was skinning in 3D Studio 4 (Which became 3d Max) decards ago now, but I’ve always hated skinning.

For this case, it was Interactive weights with geo vox"