Eyebrow mesh sinking partially into head mesh on expression changes

[Darklocq]

Any idea what would be causing this (compare right-side error images to left-side no-error caps), and how to prevent it?

 

 

It's happening on even rather minor changes of facial expression, and gets much worse on some of them, like frowning.

 

In this exact case, it's a custom-sculpted RaceMenu head, and the brows "Data\Meshes\Actors\Character\Character Assets\FaceParts\FemaleBrows.nif", not a custom brow NIF (that said, I'm not certain this is the original, vanilla FemaleBrows.nif (I do have this as a loose file, rather than it coming from "Skyrim - Meshes.bsa"). I can probably fix it for this particular character by tweaking the FaceGen head in Outfit Studio or some other tool, but that's rather error-prone – even moving the eyebrow a tiny bit outward from the head might produce a weird gap that one would see from the side view.

 

Edit: I tried the Outfit Studio approach, and that basically seems useless. The head parts to not show up in the combined mesh in their proper places (this is typical with head exports, for reasons I don't grok), so one is left to try to manually move them all around to be in the right exact spot, which is just a guesstimation. Any tiny adjustments based on that approximation wouldn't be accurate in-game.

Edited April 13, 2020 by Darklocq