# Ground Zero MVP Tile

## Decision

Ground Zero for the first real-terrain MVP tile is the Linda Mar / San Pedro
Valley edge in Pacifica, California.

This is a practical first tile because it gives the terrain pipeline varied
coastal California terrain in a compact 1 km square:

- Pacific coastal influence without starting in a dense city center.
- Hills, valley slope, drainage, and vegetation transitions.
- Nearby ocean/coastline/bathymetry cases for early pipeline design.
- Real public terrain, land-cover, hydrography, and coastline datasets are
  available from US sources.
- The environment supports the first survival loop: wood, fiber, water, shelter,
  weather exposure, and wildlife placeholders.

## Tile Identity

The MVP tile uses a simple UTM 1 km grid ID for the first prototype. This is not
the final global indexing decision; it is the concrete local key we can build
against now.

```text
tile_id: gz_us_ca_pacifica_utm10n_e544_n4160
display_name: Ground Zero - Pacifica Linda Mar / San Pedro Valley
country: United States
region: California
nearest_place: Pacifica
utm_zone: 10N
utm_easting_min_m: 544000
utm_northing_min_m: 4160000
utm_easting_max_m: 545000
utm_northing_max_m: 4161000
nominal_center_latitude: 37.5925
nominal_center_longitude: -122.4995
tile_size_meters: 1000
```

## MVP Scope

For the first pass, this tile should prove the pipeline rather than final art
quality.

- Import real elevation data into a 1 km x 1 km Unreal terrain.
- Preserve real-world horizontal scale.
- Use a conservative vertical scale that can represent hills accurately without
  making traversal unusable.
- Generate a tile metadata record and store it in the registry.
- Track source datasets and generation version.
- Add at least the eight neighboring tile records as placeholders.
- Validate that edges can be stitched to adjacent 1 km tiles.
- Infer first-pass biome and resources from terrain, land cover, water, and
  coastal influence.

## Initial Biome Direction

Working biome label:

```text
coastal_california_scrub_woodland
```

Expected early resources:

- Wood from scrub/woodland patches.
- Fiber from grasses, reeds, and coastal scrub.
- Water from drainage/creek source where present in source data.
- Stone from slope and exposed terrain placeholders.
- Wildlife placeholders appropriate to coastal California foothills.

## Source Data Targets

First-pass source candidates:

- USGS 3DEP elevation data for terrain height.
- USGS National Hydrography Dataset or equivalent for streams/water.
- NOAA coastline and bathymetry datasets for coastal/ocean handling.
- USGS National Land Cover Database or equivalent for land-cover/biome hints.
- OpenStreetMap only as a secondary reference for roads/trails/landmarks.

## Open Decisions

- Whether the final global tile grid stays UTM-based by zone or moves to a
  single global equal-area grid.
- Exact Unreal origin strategy for tiles outside the MVP area.
- How much coastline/ocean data belongs in the same tile package versus a
  separate water/bathymetry layer.
- Whether player-built state is stored per terrain tile, per settlement region,
  or in a separate spatial entity table.
