---
phase: 10
slug: feasibility-spike
status: draft
nyquist_compliant: false
wave_0_complete: false
created: 2026-03-24
---

# Phase 10 — Validation Strategy

> Per-phase validation contract for feedback sampling during execution.

---

## Test Infrastructure

| Property | Value |
|----------|-------|
| **Framework** | Manual empirical testing (hardware driver) |
| **Config file** | none — no automated test framework |
| **Quick run command** | `beyond_prox_ctl.exe "ipd_test 63"` |
| **Full suite command** | `beyond_prox_ctl.exe "ipd_test 63" && beyond_prox_ctl.exe "eyetohead_check" && beyond_prox_ctl.exe "slider_test"` |
| **Estimated runtime** | ~10 seconds (build) + manual SteamVR verification |

---

## Sampling Rate

- **After every task commit:** Run `"C:/Program Files (x86)/Microsoft Visual Studio/2022/BuildTools/Common7/IDE/CommonExtensions/Microsoft/CMake/CMake/bin/cmake.exe" --build build --config Release`
- **After every plan wave:** Full spike sequence (ipd_test -> eyetohead_check -> slider_test) with SteamVR running
- **Before `/gsd:verify-work`:** All three FEAS requirements documented in FINDINGS.md with go/no-go decision
- **Max feedback latency:** ~30 seconds (build time)

---

## Per-Task Verification Map

| Task ID | Plan | Wave | Requirement | Test Type | Automated Command | File Exists | Status |
|---------|------|------|-------------|-----------|-------------------|-------------|--------|
| 10-01-01 | 01 | 1 | FEAS-01 | smoke (empirical) | `beyond_prox_ctl.exe "ipd_test 63"` then `beyond_prox_ctl.exe "eyetohead_check"` | N/A — spike IS the test | ⬜ pending |
| 10-01-02 | 01 | 1 | FEAS-02 | smoke (log analysis) | Grep vrserver.txt for SetDisplayEyeToHead after ipd_test | N/A — spike IS the test | ⬜ pending |
| 10-01-03 | 01 | 1 | FEAS-03 | smoke (visual + event) | `beyond_prox_ctl.exe "slider_test"` + check VREvent_IpdChanged in driver log | N/A — spike IS the test | ⬜ pending |

*Status: ⬜ pending · ✅ green · ❌ red · ⚠️ flaky*

---

## Wave 0 Requirements

Existing infrastructure covers all phase requirements. The spike commands themselves ARE the tests — no separate test framework needed. Build verification (`cmake --build build --config Release`) is the only automated gate.

---

## Manual-Only Verifications

| Behavior | Requirement | Why Manual | Test Instructions |
|----------|-------------|------------|-------------------|
| IPD change visible in rendered eye separation | FEAS-01 | Requires SteamVR running with HMD active | 1. Start SteamVR 2. Run `ipd_test 63` 3. Run `eyetohead_check` 4. Compare before/after IPD values |
| Lighthouse SetDisplayEyeToHead detection | FEAS-02 | Requires SteamVR log analysis | 1. Run `ipd_test 63` 2. Check `%LOCALAPPDATA%\openvr\logs\vrserver.txt` for SetDisplayEyeToHead |
| SteamVR slider UI appearance | FEAS-03 | Requires visual inspection of SteamVR UI | 1. Run `slider_test` 2. Check if IPD slider appears in SteamVR settings |

---

## Validation Sign-Off

- [ ] All tasks have `<automated>` verify or Wave 0 dependencies
- [ ] Sampling continuity: no 3 consecutive tasks without automated verify
- [ ] Wave 0 covers all MISSING references
- [ ] No watch-mode flags
- [ ] Feedback latency < 30s
- [ ] `nyquist_compliant: true` set in frontmatter

**Approval:** pending