# Handoff Report: Milestone 2 — Character Animation & Visceral Combat Feel Engine **Date**: 2026-10-01T03:06:00Z **Author**: `challenger_m2_1_gen3` (Empirical Challenger) **Recipient**: `parent` (ID: `77cd448f-be37-473e-809c-59db9f78e386`) / Orchestrator **Milestone**: Milestone 2 (Character Animation & Visceral Combat Feel Engine) **Verdict**: **REQUEST_CHANGES** (Rejection with reproducible test suite `tests/unit/test_challenger_m2_adversarial.py`) --- ## 1. Observation ### 1.1 Baseline Test Runs Executed the three requested baseline commands: 1. `pytest tests/unit/test_m2_animation_and_combat_feel.py -v`: - Result: **30 passed in 0.15s**. - Note: Existing unit tests passed because they asserted source string occurrences (e.g. `assert "combatFeelEngine.getShakeOffset" in self.code` on `canvas_renderer.js`) rather than executing runtime function behavior. 2. `pytest tests/e2e/test_poe2_ui_animation_vfx_e2e.py -v`: - Result: **33 passed, 9 xpassed, 0 failed in 0.37s**. 3. `python tools/lint/check_code_and_doc_hygiene.py --strict`: - Result: **Exit code 0, 0 Hard Cap violations** across 530 files. ### 1.2 Empirical Adversarial Stress Suite Execution Authored and executed an empirical stress harness in `tests/unit/test_challenger_m2_adversarial.py` (325 lines, fully compliant with line hygiene caps): Command: `pytest tests/unit/test_challenger_m2_adversarial.py -v` Result: **9 failed, 80 passed in 10.57s**. Direct verbatim error traces from test execution: #### Finding 1 (HIGH): Missing `CombatFeelEngine.prototype.getShakeOffset` Method - In `client/webapp/js/engine/canvas_renderer.js:276`: ```javascript const feelOffset = (typeof window.combatFeelEngine !== 'undefined') ? window.combatFeelEngine.getShakeOffset?.() : null; if (feelOffset && (feelOffset.x !== 0 || feelOffset.y !== 0)) { ctx.translate(feelOffset.x, feelOffset.y); } else if (screenShake.timer > 0) { ... } ``` - In `client/webapp/js/engine/combat_feel_engine.js:187-208`: `CombatFeelEngine.prototype.update(dt)` calculates `this.shakeOffsetX` and `this.shakeOffsetY` along `shakeAngle` with orthogonal jitter. - Node inspection and test execution result: ``` FAILED tests/unit/test_challenger_m2_adversarial.py::TestAdversarialCombatFeelEngine::test_missing_get_shake_offset_defect AssertionError: CombatFeelEngine.prototype.getShakeOffset is missing! Directional screen shake is dead code in canvas_renderer.js assert False is True ``` - Runtime observation: `typeof combatFeelEngine.getShakeOffset === 'undefined'`. `feelOffset` is permanently `null`. The directional shake matrix computed by `CombatFeelEngine` is completely orphaned and never applied to the camera. #### Finding 2 (HIGH): 1-Tick Kinetic Phase Lag & Skipped Recovery Phase - In `client/webapp/js/engine/animation_engine.js:176-216`: Line 176 computes `kineticPhase` using `animState.frameIndex` *before* line 213 advances `animState.frameTime` and `animState.frameIndex`. Then line 237 resets `animState.kineticPhase = 'idle'` upon action completion. - Node inspection at 60 FPS (`dt = 0.01667`) for `attack_slash` (`fps = 15, hit_frame = 2`): ``` Tick 7: frame=1 phase=wind_up Tick 8: frame=2 phase=wind_up <-- frameIndex is 2 (hit_frame), but kineticPhase is still wind_up! Tick 9: frame=2 phase=impact ... Tick 12: frame=3 phase=impact <-- frameIndex is 3 (recovery), but kineticPhase is still impact! Tick 13: frame=3 phase=recovery ``` - Test execution at 15 FPS / high attack speed (1.5x-2.0x): ``` FAILED tests/unit/test_challenger_m2_adversarial.py::TestAdversarialKineticStateMachine::test_kinetic_transition_phases_progression[attack_slam-1.5-15-0.06666666666666667] FAILED tests/unit/test_challenger_m2_adversarial.py::TestAdversarialKineticStateMachine::test_kinetic_transition_phases_progression[attack_slam-2.0-15-0.06666666666666667] FAILED tests/unit/test_challenger_m2_adversarial.py::TestAdversarialKineticStateMachine::test_kinetic_transition_phases_progression[attack_slash-2.0-15-0.06666666666666667] FAILED tests/unit/test_challenger_m2_adversarial.py::TestAdversarialKineticStateMachine::test_kinetic_transition_phases_progression[attack_thrust-2.0-15-0.06666666666666667] FAILED tests/unit/test_challenger_m2_adversarial.py::TestAdversarialKineticStateMachine::test_kinetic_transition_phases_progression[attack_bolt-2.0-15-0.06666666666666667] AssertionError: Recovery phase never reached for attack_slam at 15 FPS, speed 2.0 ``` - Verbatim tick trace for `attack_slam` at 15 FPS: ``` Tick 0: 0 wind_up Tick 1: clip=attack_slam frame=1 phase=wind_up Tick 2: clip=attack_slam frame=3 phase=wind_up Tick 3: clip=attack_slam frame=4 phase=impact Tick 4: clip=idle frame=0 phase=idle ``` Phase `recovery` was never observed once by external systems. #### Finding 3 (MEDIUM): `cancelAction` Fails to Reset `currentClip` and Counters - In `client/webapp/js/engine/animation_engine.js:142-149`: ```javascript function cancelAction(animState) { if (!animState) return; animState.isActionLocked = false; animState.hitTriggered = false; animState.onHitCallback = null; animState.onCompleteCallback = null; animState.kineticPhase = 'idle'; } ``` - Test execution result: ``` FAILED tests/unit/test_challenger_m2_adversarial.py::TestAdversarialCombatFeelEngine::test_cancel_action_resets_current_clip_defect AssertionError: cancelAction left currentClip as 'attack_slash', expected 'idle' assert 'attack_slash' == 'idle' ``` - Subsequent tick trace: `updateAnimation(state, 0.0, 0.016)` sees `currentClip === 'attack_slash'`, re-evaluates `kineticPhase` back to `'wind_up'`, and continues advancing the cancelled attack clip. #### Finding 4 (MEDIUM): `CombatFeelEngine.hitStopTimer` Never Decayed in `update(dt)` - In `client/webapp/js/engine/combat_feel_engine.js:187-215`: `update(dt)` updates `screenShakeTimer` and `damagePool`, but does not decrement `this.hitStopTimer`. - Test execution result: ``` FAILED tests/unit/test_challenger_m2_adversarial.py::TestAdversarialCombatFeelEngine::test_hit_stop_timer_decays_in_update_loop_defect AssertionError: hitStopTimer failed to decay in update(dt)! Still 0.05 after 0.1s assert 0.05 == 0 ``` - Observation: `hitStopTimer` remains permanently positive on the singleton after `triggerHitStop` unless an external caller invokes `isHitStopped(dt)`. `canvas_renderer.js` only calls `update(dt)`. --- ## 2. Logic Chain 1. **Camera Shake Defect**: - `canvas_renderer.js` line 276 invokes `window.combatFeelEngine.getShakeOffset?.()`. - `combat_feel_engine.js` computes `shakeOffsetX` and `shakeOffsetY` inside `CombatFeelEngine.prototype.update(dt)`. - Because `CombatFeelEngine.prototype.getShakeOffset` was never declared, `feelOffset` is permanently `undefined` / `null`. - The directional screen shake feature is entirely bypassed at runtime, falling back to legacy isotropic shake. 2. **Kinetic Machine De-synchronization**: - `updateAnimation` in `animation_engine.js` calculates `kineticPhase` at lines 175-191 from `animState.frameIndex` before advancing `animState.frameTime` and `frameIndex` at lines 213-215. - This introduces a 1-tick latency: when `frameIndex` reaches `hit_frame` (2), `kineticPhase` is still `'wind_up'`. When `frameIndex` moves past `hit_frame` into recovery, `kineticPhase` is `'impact'`. - When action completion triggers (`frameIndex >= clip.frames.length`), line 253 immediately overwrites `kineticPhase = 'idle'`. - For fast attack speeds or lower frame rates (15 FPS), the single tick where `recovery` was assigned at line 183 is wiped out by line 253 within the exact same function call. Thus, `recovery` is never observable externally. - Moving the `kineticPhase` determination to after frame advancement eliminates the 1-tick delay and properly exhibits the recovery phase. 3. **Action Cancellation Incompleteness**: - `cancelAction` in `animation_engine.js` only sets `animState.isActionLocked = false` and `animState.kineticPhase = 'idle'`. - It leaves `animState.currentClip = 'attack_slash'`. - In the next animation update tick, `updateAnimation` reads `currentClip` and recomputes `kineticPhase` back to `'wind_up'`. - To truly cancel an action, `currentClip` must be reset to `'idle'` (or `'run'` if moving) and `frameIndex` / `frameTime` reset to 0. 4. **Hit-Stop Timer Decoupling**: - `triggerHitStop` sets `this.hitStopTimer = duration`. - `update(dt)` in `combat_feel_engine.js` is called every frame by `canvas_renderer.js:213`, but it never decrements `this.hitStopTimer`. - As a result, `hitStopTimer` on the engine singleton remains permanently positive. --- ## 3. Caveats - **No Caveats**. All 4 defects were empirically verified using real Node.js script execution against the actual codebase files, without mocks or synthetic facades. - Object pooling (`DamageNumberPool`) successfully verified: strict 64 slots, zero allocations across 256+ spawns, pop-in bounce scale curve ($1.6 \rightarrow 1.0$ and $2.0 \rightarrow 1.2$) works correctly. - Hit-stop micro-pause timing formula ($0.016 \times \text{frames}$ vs duration) and entity freeze ($33-66\text{ms}$) works correctly on `attacker.anim` and `target.anim`. --- ## 4. Conclusion **Verdict: REQUEST_CHANGES**. Milestone 2 cannot be approved in its current state because directional screen shake is non-functional due to a missing API method (`getShakeOffset`), the kinetic state machine exhibits a 1-tick phase lag causing skipped recovery animations, and action cancellation does not reset animation clip state. ### Actionable Remediation Items for Worker: 1. **Fix `combat_feel_engine.js`**: - Add `getShakeOffset()` to `CombatFeelEngine`: ```javascript getShakeOffset() { return { x: this.shakeOffsetX, y: this.shakeOffsetY }; } ``` - In `CombatFeelEngine.prototype.update(dt)`, decrement `this.hitStopTimer`: ```javascript if (this.hitStopTimer > 0) { this.hitStopTimer -= dt; if (this.hitStopTimer < 0) this.hitStopTimer = 0; } ``` - Make `isHitStopped()` pure: ```javascript isHitStopped() { return this.hitStopTimer > 0; } ``` 2. **Fix `animation_engine.js`**: - In `cancelAction(animState)`: ```javascript animState.currentClip = 'idle'; animState.frameIndex = 0; animState.frameTime = 0; animState.kineticPhase = 'idle'; ``` - In `updateAnimation`: compute `animState.kineticPhase` **after** frame advancement and action completion/looping, so `kineticPhase` is synchronized with the current `frameIndex`. - In `updateAnimation`: add `!isNaN(dt)` check to `actualDt`. --- ## 5. Verification Method 1. **Run the Empirical Adversarial Challenge Suite**: ```bash pytest tests/unit/test_challenger_m2_adversarial.py -v ``` *Expected outcome before fix*: 9 failed, 80 passed. *Expected outcome after fix*: 89 passed, 0 failed. 2. **Run Existing Milestone 2 Unit Test Suite**: ```bash pytest tests/unit/test_m2_animation_and_combat_feel.py -v ``` *Expected outcome*: 30 passed in ~0.15s. 3. **Run E2E PoE2 Test Suite**: ```bash pytest tests/e2e/test_poe2_ui_animation_vfx_e2e.py -v ``` *Expected outcome*: 33 passed, 9 xpassed, 0 failed. 4. **Verify Strict Hygiene**: ```bash python tools/lint/check_code_and_doc_hygiene.py --strict ``` *Expected outcome*: Exit code 0, 0 Hard Cap violations.