# NEXT11 V338 — checkpoint for continued work in 5.5

This is the complete working V338 root, not the small diagnostic-only archive.

## Active authority

- Runtime: `assets/nexprod/nexprod01-runtime-candidate.mjs`
- Runtime version: `NEXPROD01_RUNTIME_V338_MEDIAPIPE_RECEIVER_ZONE_2026_08_20`
- Grip audit version: `V338_MEDIAPIPE_RECEIVER_ZONE`
- Browser QA: `tools/nexprod/run_v338_receiver_zone_cdp_opengl_qa.mjs`
- QA report and actual Nex renders: `diagnostics/v338/opengl/`
- Read first: `README_START_HERE_V338_MEDIAPIPE_RECEIVER_ZONE.md`

## Locked working chain

Do not change these parts in the next focused run:

- neutral hand initialization;
- actual Index/Pinky MCP palm-surface anchors;
- whole-arm approach and palm solve;
- V335 four-finger sequential cylinder contact;
- left finger close direction `-Z` and right finger close direction `+Z`.

The thumb intentionally remains neutral/blocked and is not part of the next run.

## Verified state

- Actual Chromium/WebGL 2/ANGLE/SwiftShader Nex rendering completed for left and right hurdle-stretch keyposes.
- MediaPipe/IK produced a useful longitudinal receiver band.
- Palm snap and all four finger contacts passed numerically with zero measured penetration in the two focused cases.
- Visual limitation remains: a single keypose selects a mainly posterior radial quadrant rather than a reliably lateral sector.

V338 is therefore a safe implementation checkpoint but not final visual approval of receiver-side selection.

## Next single change: V339

Only if real sequential pre-contact MediaPipe/IK frames are present:

1. Keep the V338 longitudinal receiver band.
2. Estimate hand approach direction from several real pre-contact frames.
3. Project that approach perpendicular to the target-cylinder axis.
4. Use it to select a broad radial receiving sector.
5. Preserve the locked palm/arm/four-finger solver unchanged.
6. Render only the left and right hurdle cases through actual Nex Chromium/WebGL/SwiftShader.

If sequential source frames are absent, stop and report the exact missing temporal input. Do not synthesize a trajectory or infer it from arbitrary world axes.

## Focused QA command

The included runner currently expects Chromium at `/tmp/chromium`:

```bash
node tools/nexprod/run_v338_receiver_zone_cdp_opengl_qa.mjs
```

No broad regression, tempo tuning, amplitude tuning, thumb work or body-collision rebuild belongs in the V339 run.