Merging origin/main in ariki-game surfaced a product decision newer than this doc:
Ozan removed the mesh brows, lash cards and browless-face swap from the product path.
Brows are painted on the body texture again and keep their baked colour, so "brows
follow the hair swatch" and the generated-surface lane are both parked.
The tooling and the brow wiki page still describe the 3D lane, so the note now says to
read the code before the docs there.
Two consequences outlive the revert and are kept: painted brows are still atlas-bound,
so the v02 re-atlas has to carry the pigment (an albedo-fidelity job now, not three
artifacts to regenerate); and character_brow.gdshader is still the only mechanism that
could recolour a brow on a scanned face, since raised scan geometry cannot be erased
with a texture.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Ozan's hair system rebinds Quaternius styles (100% rigid to one Head bone) onto
whichever body loads, corrected by three hand-tuned constants in
CharacterBuildData.HeadFit. Those constants are only valid against the skull they
were tuned on, and nothing re-checks them when a body is rebaked. Both ship bodies
are currently wrong, in opposite directions.
tools/measure_head_shell.py:
--fit solve HeadScale/HairOffset from two cranium landmarks. A scale-about-
pivot plus a translate has exactly two degrees of freedom per axis, so
the crown + widest-cranium slice determine both outright -- no bed pass.
--sweep score every style against the clearance it was AUTHORED with on its own
stock rig (a mohawk stands proud, a beard hangs at the chin -- absolute
crown height is not the test).
default full Head-weighted shell AND the cranium band. The full shell is what
MakoHeadFit quotes; it is inflated several cm by jaw/ear/neck weight
bleed and is not the surface a cap sits on.
Measured against the shipped GLBs:
Lena cranium needs Y 0.960, carries 1.431 (+49%) -- every style floats 4.4-7.3cm
Mako cranium needs Y 1.186, carries 1.346 (+13%) -- every style sinks, buzz cut
2.2cm into his skull, moustache 8.0cm low
Solved constants take Mako to 0.00cm worst error over 10 styles, Lena to 0.29cm mean.
docs/characters/head-features-contract.md records the system, the measurements, and
what a 3-constant fit still cannot reach: Lena needs 1.613 in X but 1.311 in Z, a
23% anisotropy that stretches an authored cap sideways and drags ear cutouts along a
diagonal. That is Ozan's logged residual and wants a per-body geometry bake. Mako's
anisotropy is only 3%, so constants alone should suffice for him.
Also noted: the whole hair set shares just two base textures, so "authored per-colour
hair textures" -- the fix the wiki writes off in favour of the /0.55 swatch hack --
is 16 PNGs.
Crown placement is rest-pose arithmetic; X/Z and the in-bed look are unverified.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
jeremy