» Sun Nov 13, 2016 9:48 pm
The player's vampire transformation is accomplished in Skyrim by changing the player's race to its vampire variant. NPCs are already either the vampire race already or have vampire keywords and spells on their actor base. You can't change an actor's race into a race that requires exported facegen (i.e., the ten playable races, the vampire races, and Snow Elves from Dawnguard) because the vampire races areset to overlay the headparts so that the player's eyes change (the fangs are a hardcoded part of the mesh). Changing an NPCs' race causes their eyes to change, which causes a mismatch with their exported facegen; this makes their head a gray color, and any tintings, war paint, or scars are lost.
In Morrowind, most vampire NPCs have their heads set to the vampire heads, presumably because of the bug where their vampiric spells -- and consequently, their vampiric appearance, because the effect of the Vampirism magic effect is hardcoded to change the actor's appearance -- are lost after cell reset if the actor has auto-calculated stats.
You're assuming that "making vampires" functions the same way in Skyrim as it does in Oblivion and Morrowind, but it does not.