# Ground Zero Biome Resource Pass

The Ground Zero map now has a first pass of biome-appropriate natural resources
based on the selected tile's coastal California scrub/woodland biome, terrain
height, slope, and drainage-candidate analysis.

## Resource Types

- Wood: scrub/woodland and hillside patches.
- Fiber: grassland, scrub, and drainage-candidate areas.
- Edible plants: coastal scrub, grassland, and drainage-candidate forage
  patches that yield the MVP `food` item.
- Stone: slope, exposed terrain, and valley-edge areas.

Freshwater is separate from depleting resource nodes. Ground Zero uses
`BP_FreshWaterSource`, an interactable water actor that restores thirst through
the survival component.

## Implementation

- Added `BP_StoneResourceNode` through `Scripts/setup_playable_blueprints.py`.
- Added `BP_EdiblePlantResourceNode` through
  `Scripts/setup_playable_blueprints.py`.
- Updated `Scripts/setup_ground_zero_demo_map.py` to place deterministic Ground
  Zero resource nodes.
- Added `Scripts/verify_ground_zero_resources.py` to validate node presence,
  yield item IDs, remaining harvests, stable persistence IDs, and readable
  first-pass resource material assignments.
- Freshwater placement and interaction are covered by
  `Scripts/verify_ground_zero_water_source.py` and
  `Scripts/verify_water_gathering_interaction.py`.

## Counts

The map now contains:

- Wood nodes: `4`
- Fiber nodes: `5`
- Edible plant nodes: `3`
- Stone nodes: `4`

These counts include the original demo wood and fiber nodes so the first player
path remains intact while expanding the broader tile resource layer.

## Respawn Rules

MVP respawn rules separate renewable surface resources from nonrenewable stone:

- Wood nodes respawn after `900` seconds once fully depleted.
- Fiber nodes respawn after `600` seconds once fully depleted.
- Edible plant nodes respawn after `1200` seconds once fully depleted.
- Stone nodes do not respawn in the MVP.

Respawn restores the node to its configured `MaxHarvests` value and re-enables
visibility/collision through the same replicated depletion state used by
gathering.

## Tool Rules

MVP tool rules keep the first loop accessible while giving crafted tools an
immediate benefit:

- Wood, fiber, and stone nodes declare `basic_tool` as their useful tool.
- Those nodes still allow bare-hand gathering so players can gather the
  ingredients needed to craft the first tool.
- A carried `basic_tool` adds `1` extra unit to each wood, fiber, or stone
  harvest.
- Edible plant nodes remain pure bare-hand gathering.

The rule is inventory-based until equipment slots, durability, and explicit
active-hand state are implemented.

## Persistence

Ground Zero resource actors receive stable `PersistenceNodeId` values matching
their placement labels. The persistence subsystem captures and restores only
resource nodes that exist in the loaded world, so depletion records stay scoped
to active map/tile content. Future generated Earth-scale tiles should follow the
same rule: assign deterministic resource node IDs during placement and let the
save system record depletion only for tiles whose resource actors are present.

## Follow-Up

Future passes should replace the prototype meshes with real coastal scrub,
grass, rock, and woodland assets, then drive density from land-cover and
hydrography data instead of fixed authored points.