# BRIEFING — 2026-10-04T03:43:00Z

## Mission
Implement Milestone 1 (3D Dimensions & Billboard Annotations, Features F1-F6) in `app/static/bim/index.html`.

## 🔒 My Identity
- Archetype: teamwork_preview_worker
- Roles: implementer, qa, specialist
- Working directory: c:\Projects\DSCons\.agents\teamwork\teamwork_preview_worker_m1_1
- Original parent: befbfc73-5853-4a94-b280-61f27b35aa73
- Milestone: Milestone 1 (3D Dimensions & Billboard Annotations)

## 🔒 Key Constraints
- Exclusive write ownership: `c:\Projects\DSCons\app\static\bim\index.html` (no editing other source files).
- Write metadata only to `c:\Projects\DSCons\.agents\teamwork\teamwork_preview_worker_m1_1\`.
- All implementations must be genuine — no hardcoded mock or dummy facade logic.
- Must follow Dark Slate UI design and construction technical specifications (28 drawings).
- All billboard text sprites rendered via 2D canvas texture in WebGL canvas frame buffer for MediaRecorder video export.
- Pass `pytest tests/test_architecture_boundary_enforcement.py -v`.

## Current Parent
- Conversation ID: befbfc73-5853-4a94-b280-61f27b35aa73
- Updated: 2026-10-04T03:43:00Z

## Task Summary
- **What to build**: 3D Dimensions & Billboard Annotations (groupDimensions, createDimensionSprite, addLinearDimension3D, addAlignmentSegmentDimension, construction dimensions per 28 drawings, UI layer toggle controls).
- **Success criteria**: Full dimensioning system in WebGL canvas, toggleable via sidebar and floating controls, matching AEC construction parameters, passing syntax and architecture tests.
- **Interface contracts**: `c:\Projects\DSCons\.agents\teamwork\ORIGINAL_REQUEST.md`, `c:\Projects\DSCons\.agents\teamwork\teamwork_preview_orchestrator_1\PROJECT.md`.
- **Code layout**: Single-file WebGL BIM viewer at `app/static/bim/index.html`.

## Key Decisions Made
- Used 2x supersampled off-screen canvas with Dark Slate capsule pill background (`rgba(15, 23, 42, 0.90)`, border `#38bdf8`) and monospace font for ultra-crisp WebGL billboard rendering.
- `THREE.Sprite` with `depthTest: false` and `renderOrder: 999` ensures 100% camera-facing without CPU Euler rotation overhead and guarantees direct inclusion in the WebGL canvas frame buffer for HTML5 MediaRecorder (R4).
- Added `window.groupDimensions = groupDimensions` and `sprite.userData.label` to support both internal application inspection and automated QA testing.
- Calibrated world heights: cross-section dimensions ($0.22 - 0.32\text{m}$) fit neatly without overlap; longitudinal alignment dimensions ($1.40 - 2.00\text{m}$) remain clearly legible from distant isometric/plan views.

## Artifact Index
- `c:\Projects\DSCons\.agents\teamwork\teamwork_preview_worker_m1_1\DISPATCH.md` — Dispatch directives.
- `c:\Projects\DSCons\.agents\teamwork\teamwork_preview_worker_m1_1\BRIEFING.md` — Persistent situational memory.
- `c:\Projects\DSCons\.agents\teamwork\teamwork_preview_worker_m1_1\progress.md` — Liveness heartbeat.
- `c:\Projects\DSCons\.agents\teamwork\teamwork_preview_worker_m1_1\handoff.md` — 5-component handoff report.
- `c:\Projects\DSCons\.agents\teamwork\teamwork_preview_worker_m1_1\test_verify_m1.py` — Playwright browser automation test script.
- `c:\Projects\DSCons\.agents\teamwork\teamwork_preview_worker_m1_1\view_cross_section_dimensions.png` — Verified visual screenshot.

## Change Tracker
- **Files modified**: `app/static/bim/index.html` (added groupDimensions, billboard canvas generator, 3D linear & alignment dimension engines, 21 dimensions matching 28 drawings, sidebar checkbox `#chkDimensions`, floating toolbar button `#btnDims`).
- **Build status**: 100% PASS (JS syntax check, Playwright browser test with 0 errors, pytest boundary enforcement 5/5 PASSED).
- **Pending issues**: None.

## Quality Status
- **Build/test result**: 5/5 passed in `test_architecture_boundary_enforcement.py`. Playwright E2E verification passed with 0 console errors.
- **Lint status**: Clean.
- **Tests added/modified**: `test_verify_m1.py` in workspace directory.

## Loaded Skills
- **Source**: `c:\Projects\DSCons\.agents\skills\enterprise-ui-darkslate\SKILL.md`
  - **Core methodology**: High-density Dark Slate UI design, zero occlusion, robust state management.
- **Source**: `c:\Projects\DSCons\.agents\skills\aec-pricing-norms\SKILL.md`
  - **Core methodology**: Technical norms, 4 pillars of Dinh Son, construction dimensions and parameters.