THE STREET AS A LIVING ROOM — SHAM SHUI PO C2

This revision replaces the schematic two-exit scene with the real C2 street at
Kweilin Street / Apliu Street. One scene unit is one metre. The user's reference
photograph establishes C2, checked against the official MTR map and C2 imagery.

REAL CITY DATA
The default view contains 135 textured GLB tiles (44.29 MB, 790,372 triangles)
from the Lands Department 3D Visualisation Map, tile 11-NW-14A. The finest
available core leaves are L20, with surrounding L19 context and one L16 leaf.
The selected hierarchy has no overlapping parent/child tiles. Textures are
baked aerial imagery, displayed unlit to preserve their photographic colour.
Source tile revision: 2025-12-22. Retrieved: 2026-10-11.
Photographic capture date: unverified. Published absolute accuracy: ±0.30 m
horizontal, ±0.50 m vertical. Relative accuracy: ±0.20 m. Heights: Hong Kong PD.
Source acknowledgement: Lands Department, Government of the Hong Kong SAR.
https://portal.csdi.gov.hk/csdi-webpage/dataset/landsd_rcd_1671677054006_62261
https://portal.csdi.gov.hk/csdi-webpage/metadata/landsd_rcd_1671677054006_62261/html

Mapped Geometry separately displays 308 mapped building parts, recorded base
and roof elevations, road centrelines and the government pedestrian network.
Building dataset:
https://portal.csdi.gov.hk/csdi-webpage/dataset/landsd_rcd_1637211194312_35158
Official MTR map:
https://www.mtr.com.hk/archive/en/services/maps/ssp.pdf

COORDINATES AND REPRODUCTION
Vector source data is retained in data/source (EPSG:2326, HK1980 Grid).
Origin: E834689.930455, N821289.807830; vertical origin 4.4 m PD.
Local X points southeast, local Z southwest, local Y up.
The C2 canopy is source OBJECTID 52806 / GeoRefNo 3469421294, with base 4.4 m
and top 7.8 m PD. Its official footprint is approximately 2.8 m × 12.3 m.
The nearby Ap Liu Street Public Toilet is OBJECTID 177652.
Each city GLB's column-major localMatrix converts raw source vertex positions
into this same metric frame. The source payloads and matrices are retained in
dist/assets/city. No API key is required at runtime.
Run python scripts/prepare-site.py with matplotlib installed to regenerate
src/data/site.json and data/local-plan.png from retained vector data.
The map-data ZIP includes the compact scene data, raw vectors and source manifest;
Download visible GLB in the viewer exports the currently selected 3D scene.

ACCURACY AND INTERPRETATION
Actual captured street/building geometry is preserved. Aerial photogrammetry
can blur or omit small objects, covered areas and fine entrance details.
Mapped Geometry uses estimated road widths and reconstructed entrance surfaces,
windows, stools, luggage and railings. These are not surveyed features.
Measure reports horizontal distance between selected mesh points in capture
mode, or points on the reference ground plane in mapped mode. It is a visual
study aid, not a certified survey or an accessibility compliance check.
The seating study adds two compact removable benches; it does not relocate any
building. On-site clearance, access, ownership and current conditions remain
to be checked. Simulated people do not represent crowd capacity or movement data.

CONTROLS
Drag to orbit, scroll to zoom, right-drag to pan. Touch gestures are supported.
Existing / Seating Study keeps the same camera. Walking Network reveals mapped
outdoor paths. Buildings toggles mapped blocks only. Free flight uses W/S, A/D,
R/F and mouse drag. Manual interaction stops the 20-second camera tour.
Eye-level, overview, plan, neighbourhood and seating cameras share one model.

FILM AND NARRATION
Film uses the supplied documentary photograph, a January 2026 C2 photograph
and a January 2026 Kweilin Street photograph for the first forty seconds. The
final twenty seconds use this same C2 scene. Source and license credits are
in dist/assets/photos/sources.json and under Photo Sources on the Film tab.
Commons photo sequences are adapted under CC BY-SA 4.0 (crop, motion, captions). Export Current MP4 waits for the actual city mesh.
The old AI-illustrated preview MP4 is no longer linked. Export Current MP4
creates the revised real-photo film in a browser with video encoding support. Old social-pocket GLBs, presentation-package.zip and storyboard PDF
are also historical assets retained from the previous version, not new surveys.
For narration, run the existing local Studio launcher, connect ElevenLabs,
choose a voice and generate/import each ten-second scene. Save Project retains
scripts/audio, never the API key. Generation uses the user's ElevenLabs credits.
The public static site supports audio imports; generation requires the local
helper. Local saves must be republished to update the hosted presentation.

BUILD AND VALIDATION
npm install
npm run build
npm test
npm start (local narration helper)

Validation covers timeline behaviour, C2 metric footprint, GLB integrity,
embedded textures, transform orthonormality, ground alignment, fixed geometry
across proposal states and every linked static asset. Independent top-down mesh
vertices were visually compared with government footprints; street axes and
building blocks align. Browser/WebGL QA was unavailable in the build environment.
Source: src; published static output: dist. Keep credentials out of both.
Libraries: Three.js, Lucide, Mediabunny, esbuild. The film uses real source
photographs and the 3D study. Legacy generated art is not used by the film.

LOCAL CAPTURE REPAIR
The aerial mesh fused the lower tree canopy into a mound at approximately
local X=-5.2 m, Z=-22.4 m. src/capture-repair.js removes this malformed skirt
below 3.8 m, keeps the captured upper canopy, reconstructs a trunk, and flattens
low noisy pavement triangles in a bounded street corridor. The C2 entrance
envelope and vertices outside that repair area are preserved. The new ground
and tree trunk are reference-based visual repairs, not a measured survey.
The original source GLBs stay intact; the repair is applied to display/export.

PRESENTATION REVISION
The opening camera uses a closer elevated view; selecting a camera animates
between views. Numbered movement, gathering and belongings overlays explain
the current study without modifying real building/entrance geometry. These
zones are indicative graphic overlays, not approved route widths. Real-street
and architectural modes share coordinates. The film uses full-frame photos,
short dissolves, chapter titles, high-contrast captions and source credits.

SUNKEN COURTYARD REVISION
The current proposal supersedes the earlier removable-seat trial.
Assumed footprint: X -11 to -2.6 m, Z -16 to +5 m (8.4 x 21 m).
Assumed floor level: -3.2 m relative to the street datum; deck thickness 0.24 m.
All proposal dimensions are provisional design choices, not survey findings.
The existing C2 entrance stays in its mapped position. The proposal cuts only
its own footprint out of cloned display/export geometry, interpolating vertex
attributes to retain the surrounding city textures. Raw city assets stay intact.
Switching to Existing restores the original geometry.
Cutaway removes city context and the west retaining wall to reveal the lower
floor. Stairs at both ends, a lift reservation, sheltered seating, shared tables,
bag bays, fans and lighting are included. Normal and peak illustrations show
10 and 24 schematic occupants; these are not capacity estimates or simulations.
No claim is made that this footprint is available, that excavation is feasible,
or that the scheme adds a quantified usable capacity. Existing street uses
would be affected. Station structures, utilities, land rights, flood protection,
ventilation, structural design and accessible/escape routes require investigation.
Sources: MTR Railway Protection,
https://www.mtr.com.hk/en/corporate/operations/protection_index.html
Hong Kong Government flood resilience response (24 April 2024),
https://www.info.gov.hk/gia/general/202404/24/P2024042400282p.htm
Visual review used an offline geometric cutaway and a rendered SVG section.
These are not browser/WebGL screenshots. Browser QA remains unavailable.
