A question about mesh parts 'bleeding through'.

[scorrp10]

I have been playing around with DX Cassandra Apocrypha Robes, doing a CBBE 3BA BodySlide conversion, and as part of it,  doing proper SMP on the skirt, since the original is kinda rigid.   So the original already had a few skirt bones laid out, but nowhere near enough to provide full structure.

So I extend the bone structure, repaint all the weights, add virtual ground and legs collision shapes...

I put together the SMP xml, and in game, it looks pretty good.

But I decide that I want smoother motion, so I decide to add a couple more bone rows.    And here, the problem strikes.


As you can see, portions of the skirt mesh are now showing THROUGH the virtual legs,  and in the game these mesh portions are showing through actual legs.   All that was changed is addition of like 12 more bones (which is still well under the limit of 80), and weight repaint.    Usually, artifacts like those happen because of messed up normals.   Except I did not change the mesh at all, and I re-checked the mesh in Blender, all normals are 100% fine.   No changes in the shader either.

Any thoughts anyone?   Thanks.