H.A.I.R. grew the player's hair and beard in real time instead of freezing it at character creation. The heart of it is a growth graph: every vanilla Fallout 4 hairstyle is sorted into a length tier, and as in-game time passes the active style advances one tier — branching into a longer style picked by the character's preference. This lab maps that whole system from the design files.
This is the real model. Every vanilla style — 32 male, 27 female, 44 beard — was visually analysed and sorted into length tiers with a growth branch map. The previews below are the actual in-game renders of each style. H.A.I.R. itself was a 2016 work-in-progress that was never publicly released, so consider this the design laid bare.
Read the columns left-to-right as time passing. Each style sits in its length tier (L0 = shaved → higher = longer). Hover any style to light up the styles it can grow into — the engine picks one branch based on the character's preference family (slick, messy, afro, full…), weighted by chance. Beards and female hair use the same mechanic with their own tier ladders.
Fallout 4 has no continuous hair length — only discrete styles. So growth is modelled as a graph over those styles: each one knows which longer styles it can become. Advance a tier and the system swaps the mesh. Branching by preference keeps two characters from growing identical hair.
H.A.I.R. used F4SE native Papyrus to tick a growth counter against in-game time and swap HeadParts at each tier — no character menu needed. Freshly-cut undercuts even regrow via a secondary "baseline" HeadPart layered on top, so shaved areas fill back in over time.
The original 2016 WIP preview lives on CDante's channel — this lab is the growth system behind it, rebuilt from the design files.
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