Paint Skin Weights in Maya 2011 causing vertices to move?

Ricky

Hi, i'm having a bit of a frustrating problem with Maya 2011, that i've never ran into before in earlier versions of Maya. When i paint skin-weights on my character, somtimes random vertices will suddenly move to world 0,0,0...? If i look in the attributes editor to see weight information and specify joints to have complete control like his shoulder joint for example, it makes no difference. I can't seem to re-weight them to where they are supposed to be after they have done it either.

Any help would be much appreciated!

Pyro_Kyle

I'm having a similar problem. I have a character that when I paint skin weights on the torso verts in the arm suddenly start moving. any help would be greatly appreciated.

michiy

That happens because when a vertex that has NO weight painted on it automatically moves to the 000 of the world.

To avoid that when painting low poly meshes (the 1 bone to 1 vertex influence) you can weight paint the desired vertex to be influenced by another joint.

Maybe that helps. If you need more information I can do a quick sketch for you.

michiy

Well I've dealt with this kinda problem also. This problems happens because the vertex has no "weight" painted on it and this causes it to move to the world Origin (0,0,0). To deal with this when painting low poly meshes you can simply "transfer" the weight from the joint to the desired joint.

So another way to fix this problem is to avoid painting using the "Replace weight" brush, but always use the "Add" brush to paint. The weight value of a vertex ranges from 0 to 1. For example, if you have 2 joints and both of them are equally distant from the vertex, for the both joints the weight value for that particular vertex will be 0.5. Get it?

I can do a quick diagram in case of further difficulties.

throttlekitty

I've never ran into this either. michiy, what do you mean by 'transfer' there?
I would probably select the offending verts outside of paint mode, and flood them to 1.0 to a bone and fix the result.

Pro_Kyle, perhaps the skeleton was posed and needs to Skeleton>Revert to bind pose (forget the exact menu path offhand)

ivars

In 2011 the default normalization when binding a smooth skin is set to "post" (previous versions it was interactive) meaning that verts can have a total weight value less or more than one. That means, if you are removing weights from a vert, it will not automatically be assigned to a neighboring joint like it would before.
You can change the normalization in the skin cluster node, but before doing that you will have to normalize the weights manually (Skin > Edit smooth skin > Normalize weights)
After that, the painting will behave more like you're used to

(It seems a lot of the previous defaults was changed with the new UI in 2011, so remember to check the settings before you apply things...)

Tejvir

HI 

problem:

i am facing is one vertex move automatically , it has wight of two bones but not moving with bone

Solution:

export the skin weight of fully from deformexport not from skin menu and reinport the skin weight.

Thanks