Orc Skills

---
name: rig-it
description: Rig and animate game characters that actually hold up in-engine. Contract-driven Blender pipeline with body-plan scaffold rigs for creatures, Mixamo-skeleton packaging for bipeds, rest-pose weight transfer, rigid part seating, numeric gates on a fresh reimport, rendered review frames and reels, Unity Humanoid/Generic export. Use when the user wants to rig a character, skin a mesh, build an armature, author or fix Idle/Locomotion/Attack/Hit/Death clips, package Meshy or Mixamo animations onto a production mesh, stop feet sliding or sinking, get a rig into Unity or Godot, or mentions rigging, skinning, weights, IK, gait, Mixamo, Meshy rig, Humanoid avatar, or invokes /rig-it.
---

# rig-it

Rigging fails in chat because the model writes one script, gets an armature
that binds, and never sees that the elbow is wrong. This skill never lets you
judge a rig from the code that built it. Every rig and every clip goes through
a contract, a family route, verified weights, numeric gates on a fresh
reimport, and rendered frames you look at before anyone calls it done.

Read [RULES.md](RULES.md) before touching a mesh. Run
[WORKFLOW.md](WORKFLOW.md) commands as written. Family bone lists live in
[references/body-plans.md](references/body-plans.md).

## The loop

```
contract  ->  route  ->  rig + weights  ->  clips  ->  export  ->  fresh reimport
   ^                                                                    |
   |                        polish passes (never thresholds)   <--  gates + frames
```

1. **Contract first.** Write `rig-contract.json` (schema in
   [templates/](templates/rig-contract.json)): family, engine rig type,
   required clips, rigid parts with sockets, gameplay move speed. Tooling
   reads it; tooling never redefines it.
2. **Route by body plan, not by wish.**
   | Body | Route | Scripts |
   |---|---|---|
   | Biped that a Mixamo-template rigger accepts (Meshy, mixamo.com) | rig input, provider rig, preset motions, package onto the production mesh | `rig_input.py`, `package_biped.py` |
   | Quadruped, hexapod, octopod, flyer, maw, winged hybrid, humanoid the provider mangles | deterministic scaffold rig from bounds, bind, author contact-driven clips | `scaffold_rig.py`, `author_clips.py` |
3. **Weights are verified, not assumed.** Automatic weights are a starting
   point. Unweighted vertices fall back to the nearest bone. Max 4 influences,
   normalized. Sole patches harden to the foot bone. Provider weights
   transfer onto the production mesh with both meshes in rest pose.
4. **Stationary navigation root.** `Root` carries no skin weight and never
   moves. Body motion lives on the body bone. Root motion is off in engine.
5. **Rigid parts** are skinned 100% to one hand bone and seated with a grip
   rule. Never bone-parented (FBX pivots differ).
6. **Export, then judge the reimport.** `export_fbx.py` writes one FBX per
   clip plus the production multi-take FBX. `review_clips.py` reimports each
   clip into an empty scene, measures every frame on real vertices, renders