Good afternoon. I ask for help in transforming clothes.
As a basis for cloning, I took a sweater from the author Nikaonishko, since she has similar volumes.
Tied the bones. Ultimately, this is what I got in this area:
I've converted quite a lot of things so I'm NOT a newbie. But this is the first time I've encountered this...
Maybe you need to additionally bind the bones in the Joints tab in the milkshape?
Many creators have similar voluminous sweaters, and all of them are neat, not like mine.....)

Does the original sweater look like this or is this after you made changes?

What do you mean by tying the bones?

Here's the original if it helps anyone. https://jessisimsccfinds.tumblr.com...y-ruby-original

I took the sweater by Nikaonishko as a reference, exporting it in tsrw format. In order to attach bones to a beige sweater using the MeshToolkit program.
But the binding in the armpit area looks bad...

Ah, I thought that you'd made changes to the bones of the original sweater.

Bones often don't transfer perfectly. You'll have to compare the bones on the original sweater with the ones on the new one and see where they differ, then fix the ones that haven't copied properly manually, AFAIK.

Do you know how to use the Unimesh Bone Tool (under the Vertex menu)?

It honestly looks easier to try copying the textures onto nikaonishko's sweater.

I tried this method, it still didn't work(
I don’t know what else can be done..
As for the texture transfer, I also thought that it would be easier, but this sweater is not the only one where there is a problem. Therefore, something needs to be decided)

I wouldn't be able to suggest anything else without looking at the files. Can you upload them?

I did it differently. The thing is that in the blender (regarding the top) I always raised and twisted the joints of my hands to a certain degree. (if I'm expressing myself correctly)
But due to the fact that the sweater has such a free volume, such a defect appeared in the armpit area. And the point, as I already understood, is not at all about the binding. I've tried a bunch of different bone binding sweaters. to no avail)

Therefore, I had to manually twist the “arms” in the milkshape, adjusting them to the skeleton. And the result in the game turned out to be much better)

Glad you got it sorted out.