# BRIEFING — 2026-10-04T03:50:00Z

## Mission
Adversarial geometric and WebGL buffer verification for Milestone 1 (3D Dimensions & Billboard Annotations) in app/static/bim/index.html.

## 🔒 My Identity
- Archetype: EMPIRICAL CHALLENGER
- Roles: critic, specialist
- Working directory: c:\Projects\DSCons\.agents\teamwork\teamwork_preview_challenger_m1_2
- Original parent: befbfc73-5853-4a94-b280-61f27b35aa73
- Milestone: Milestone 1 (3D Dimensions & Billboard Annotations)
- Instance: 2 of 2

## 🔒 Key Constraints
- Review-only — do NOT modify implementation code
- Empirical verification mandatory — must run verification code myself; no unverified claims
- .agents/teamwork/ must contain only metadata — do not place test scripts or code here
- Adhere to AGENTS.md, GEMINI.md, and ORIGINAL_REQUEST.md requirements

## Current Parent
- Conversation ID: befbfc73-5853-4a94-b280-61f27b35aa73
- Updated: 2026-10-04T03:44:45Z

## Review Scope
- **Files to review**: app/static/bim/index.html
- **Interface contracts**: c:\Projects\DSCons\.agents\teamwork\ORIGINAL_REQUEST.md, c:\Projects\DSCons\.agents\teamwork\teamwork_preview_orchestrator_1\PROJECT.md
- **Review criteria**: Exact scene graph child counts (21 THREE.Sprite, 20 THREE.LineSegments in groupDimensions), Euclidean distance matching labels (2.5m, 3.0m, 3.4m, 50m, etc.), WebGL canvas captureStream(30) integration, FPS > 30 regression check.

## Key Decisions Made
- [Initial] Initiating adversarial evaluation with automated browser / WebGL inspection scripts.
- [Empirical Test 1] Created `tools/verification/test_adversarial_m1_geometry_and_webgl.py` inspecting scene graph, Euclidean distances, and FPS.
- [Empirical Test 2] Created `tools/verification/test_adversarial_m1_media_recorder.py` capturing 54KB video stream chunks with MediaRecorder.
- [Empirical Test 3] Created `tools/verification/test_adversarial_m1_pixels.py` checking offscreen canvas textures rasterized into WebGL framebuffer.
- [Verdict] Verdict formulated: APPROVE. All 21 dimensions, Euclidean distances, captureStream(30) buffer integration, and 75.4 FPS pass with zero regressions.

## Artifact Index
- DISPATCH.md — incoming dispatch instructions
- progress.md — liveness heartbeat and execution log
- handoff.md — final 5-component handoff report
- tools/verification/test_adversarial_m1_geometry_and_webgl.py — automated Playwright scene graph & geometry checker
- tools/verification/test_adversarial_m1_media_recorder.py — MediaRecorder captureStream verification
- tools/verification/test_adversarial_m1_pixels.py — WebGL texture buffer verification

## Attack Surface
- **Hypotheses tested**:
  1. Exactly 21 THREE.Sprite and 20 THREE.LineSegments in groupDimensions: CONFIRMED (41 children total, 21 Sprites, 20 LineSegments, 0 unknown).
  2. Euclidean distances $\|\mathbf{P}_B - \mathbf{P}_A\|$ match labels: CONFIRMED (e.g. 2.5000m, 3.0000m, 3.4000m, 0.2500m, 0.2000m, 7.0000m, 6.0000m).
  3. canvas.captureStream(30) draws all 21 sprites: CONFIRMED (active track, 54,759 bytes webm recorded with 21 sprites rendered).
  4. FPS regression test: CONFIRMED (Average FPS = 75.43 FPS, Min FPS = 74.07 FPS > 30 FPS threshold).
- **Vulnerabilities found**: None. The implementation exhibits robust mathematical precision and clean WebGL integration.
- **Untested angles**: Full 90-day 4D BIM playback (deferred to Milestone 2).

## Loaded Skills
- **Source**: c:\Projects\DSCons\.agents\skills\enterprise-ui-darkslate\SKILL.md
- **Local copy**: Referenced from project skills
- **Core methodology**: Enterprise UI standards, high density, real browser validation.