# MB-001 handoff pack

MB-001 is a **remote-only** stereo-camera head rig: two USB cameras on a 2-axis (pan/tilt) servo gimbal, driven by a rig machine (Raspberry Pi 5) that receives the Apple Vision Pro wearer's head pose (yaw, pitch) and streams stereo video back. Nothing is mounted on the headset; the only wireless hop is rig machine → Vision Pro over Wi-Fi 6.

This pack lets an AI coding agent (or a human) implement it in **TouchDesigner**, including a **simulator** that uses the 3D model.

## Start here
1. Read **`HANDOFF.md`** (self-contained spec; every fact is tagged **[S]** sourced, **[D]** derived/computed, **[E]** estimate, **[?]** unverified; sources at the end).
2. Load a model from `models/<variant>/` (default **`module38_sts3215`**). GLB/FBX are **mm, y-up, named nodes, pivots on the joint axes**: `base > yoke(pan) > cam_bar(tilt) > cam_L / cam_R`.
3. Read machine-readable numbers from `data/params.json`.
4. Build the simulator and pass the acceptance tests in HANDOFF §13.

## Contents
| Folder | What |
|---|---|
| `HANDOFF.md` | the spec |
| `models/<variant>/` | `.glb`, `.fbx`, single-file `_assembly.obj` (rest pose, y-up), `parts_stl/` (one STL per part: CAD frame z-up, mm, origin at the part's joint/link origin), `parts_obj/` (same parts, y-up). Variants: `module38_sts3215`, `module38_sh0257`, `brio_mg996r` |
| `urdf/` | `mb001_<variant>.urdf` (CAD frame, metres, meshes referenced relatively) |
| `data/` | `params.json`, `cameras.csv`, `wiring.svg`, `latency-pipeline.svg`, `validation.json` |
| `cad/` | `mb001_rig.scad`, `REEXPORT.md`, generator `scripts/` |

## Honest limits
- No TouchDesigner was available while preparing this pack: TD steps are from the Derivative docs or marked [?]; check them with the §13 tests.
- Camera bodies, Pi, PCA9685 and UBEC are placeholder boxes; the camera depth (15 mm), optical centre, FOV and mass (100 g) are unverified.
- Tilt limit ±30° is an **estimate**. All latency figures are **estimates**. The UDP port (5005) is a **proposal**.
- Conflicting vendor numbers are listed, not resolved (HANDOFF §14).
- Pan + = cameras turn left; tilt + = pitch up; UDP yaw + = look right (so pan = −yaw). Verified on the box via URDF/GLB kinematics, **not** in TD.