zwitschi
81f7cd3991
Merged PR #25: Mapbox building-height cross-check Co-authored-by: Zwitschi <zwitschi82@gmail.com>
47 lines
3.0 KiB
Markdown
47 lines
3.0 KiB
Markdown
# Geo
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Geographic sources, manifests, and the tools that turn them into Blender and Unreal content.
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OSM is layout data only. It is not authoritative for façade detail, height, or pavement, and it is never sampled as a texture or panorama source.
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## Layout
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| Path | Contents |
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| --- | --- |
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| `Geo/raw/` | Verbatim source responses and downloads, checksummed. Never edited by hand. |
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| `Geo/manifests/` | One manifest per source: extract, DEM, and the local origin |
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| `Geo/verification/` | Per-pass notes: address, footprints, bounds, street profile, cross-sections, elevation |
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| `Geo/tools/` | Every geographic tool (Python, standard library only unless noted) |
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Tools that build 3D content from these sources live next to their output in `Art/blender/*/` (`terrain_from_dem.py`, `street_mesh.py`, `site_assembly.py`, `blosm_blockout.py`) because they need Blender; their shared geo helpers and the unit conversion come from `Geo/tools/osm_common.py`.
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## Tools
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| Tool | Purpose |
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| --- | --- |
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| `osm_common.py` | Shared helpers: parse `.osm`, stitch and clip a street, project to UTM through PROJ, **and the single metres→centimetres conversion** (`to_unreal_local`) |
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| `block_report.py` | Streets, boundary intersections, and the building set for a block, split by side |
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| `block_height_report.py` | Every block building with its height **source** — tag, levels × 3.2 m, or a placeholder guess |
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| `street_profile.py` | Carriageway width from crossings, sidewalk offsets, per-building setbacks |
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| `street_section.py` | Cross-sections from the DEM: crown, gutters, kerb detection |
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| `elevation_probe.py` | Samples 3DEP for relief and records the baseline for the release checks |
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| `dem_stats.py` | Stdlib reader for the tiled GeoTIFF the 3DEP service returns; GDAL does not run on this host |
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| `asset_metadata.py` | Writes and audits `<asset>.geo.json` sidecars: position, provenance, conversion |
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| `mapbox_buildings.py` | Cross-checks every building's height against Mapbox `mapbox-streets-v8` building data (Tilequery per centroid), merging our OSM height + source with theirs and flagging matches, close, disagreements, non-building volumes. Needs `MAPBOX_ACCESS_TOKEN` in `.env`; caches responses under `Geo/raw/mapbox-cache/`, and **both the cache and its report are gitignored** (Mapbox terms restrict redistribution) |
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## Unit boundary
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There is exactly one conversion in the repository:
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```
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WGS84 (lat, lon) → EPSG:26911 (E, N metres) → project-local metres → Unreal centimetres
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```
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`Geo/tools/osm_common.py::to_unreal_local` is the only place that multiplies by 100. Per-asset sidecars record the result, and `asset_metadata.py audit` checks each saved sidecar against that function, so a file that drifts is caught rather than trusted.
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## Current state
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The extract, both El Capitan footprints, the demo bounds, the building sets, the street profile, cross-sections, and the 3DEP DEM window are recorded in `Geo/verification/` and `Geo/manifests/`. The local CRS and origin are fixed in `manifests/local-origin.md`.
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Open items live in `TODO.md` under **Geographic data**.
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