Miku shipped with 0 cloth chains against Taila's 35, so her twin tails
hung off her skull like a helmet. Nothing downstream could fix it: the
spring solver simulates cloth BONES, and a garment with none is welded to
whatever body bone it was weighted to. Every auto-rigged model is in that
state, and her source was an unrigged mesh.
tools/cloth_bones.py builds them, which is the job a technical artist does
by hand on a model like this. It finds the geometry by MATERIAL SLOT — the
artist already answered which surface is hair, and on a joined mesh (what
the auto-rig leaves behind) the slot is the only separation left. Hair is
split into connected islands, because a strand is a connected piece of
surface and clustering by position would merge two ponytails passing near
each other. A skirt is split into radial wedges instead, because a skirt
is ONE connected surface and islands would return the whole thing as a
single piece — the bell-shaped failure. Each clump gets a polyline fitted
down its middle by binning vertices by distance and taking centroids, so
the chain follows the piece's own curve rather than cutting the corner on
a bend, and vertices are re-weighted onto it while the first 22% keeps its
original body weight so the scalp stays on the skull.
On Miku: 19 chains, 57 bones from one `hair` slot. Sidecar 0 -> 19 chains.
Idle stability 0.007-0.018 deg/frame. Mesh intact, verified by render.
Opt-in, via `pipeline.py --grow-cloth`, and run before the retarget so
describe_rig() finds the chains by name exactly as it would an artist's.
Known limits, recorded in the skill: it cannot find a garment sharing a
material with the body (Miku's skirt is on her `body` slot, so she got
hair and no skirt), and grown chains are a fallback — an artist's chains
carry intent that no geometric fit recovers.
Co-Authored-By: Claude Opus 5 <[email protected]>
New selectable skin: Taila (original anime character by Partaevil,
CC-BY, license kept alongside the model), cel-shaded with ink outlines,
running the full 18-clip animation set + the new rifle-hold pose layer.
Pipeline hardening learned the hard way (each of these produced a broken
character before the fix):
- tools/strip_rig.py: strips a foreign rig (VRoid/Mixamo names bake FLAT
clips in the name-based retarget), keeps only meshes skinned to that rig
(scene props were joining into the player model), recentres feet-on-origin,
and reroutes image textures into Principled base color for re-export.
- tools/unlit_to_pbr.py: KHR_materials_unlit anime models carry their albedo
in emissiveTexture over a black base — Blender 5.1 drops the texture on
import, rendering the character pitch black. Rewrites the GLB JSON to
standard textured PBR before Blender ever sees it.
Also dropped the Elle import attempt: her rest pose is seated (posed scene),
which the T-pose autorig cannot use.
Co-Authored-By: Claude Fable 5 <[email protected]>
