islaApocalypse/Server/README.md

Server Module

Authoritative world building. Turns the static WorldBlueprint in RAM into physical 3D chunks. In a future multiplayer setup this is the side that dictates terrain and ships chunk data to clients.

ServerChunkManager.cs

Attached to the World root node of Scenes/Main.tscn. Runs the whole 3D world at boot.

Startup

1. Loads ServerConfig.json and the seed's .dat blueprint (v2 or legacy v1 — the parser dispatches automatically; see Core/Scripts/BLUEPRINT_FORMAT.md).
2. Cross-checks the blueprint's embedded params (v2 only) against the config and logs a prominent BLUEPRINT/CONFIG DESYNC warning if the seed or MapSize disagree — a config edited after generation is loud now, not silent.
3. Finds the Capitol in the parsed town list and uses it as the world origin point.
4. Converts its pixel position to chunk coordinates (pixel / CHUNK_SIZE).
5. Builds a (2 × ChunkRadius)² grid of chunks around it — synchronously, all at boot.
6. Teleports the Camera3D to 120 m above the Capitol, looking down.

⚠ Two things to know about startup. The chunk grid is built in one blocking pass with no streaming or unloading, so ChunkRadius directly controls boot cost — 32 means 4,096 chunks and roughly 3.6 GB. And the camera LookAt points straight down, which is a degenerate case: the up vector ends up parallel to the view direction, so camera roll is undefined and Godot logs a warning.

Per-chunk generation

• Road culling first. Only the road segments whose bounding box reaches this chunk are kept, each tagged with its RoadTier. The padding is derived from the widest shoulder any tier has plus a margin, so widening a road cannot silently truncate it at chunk edges.

• Water per column (tasks 13, 15) — the blueprint is the authority on where water is and at what level; the server only reads it. WSRF gives the surface level per pixel, and the WBTB body table is the fallback when a column is flagged wet but carries the WSRF no-water sentinel.

  Presence takes two clauses. WBID (the water stage's own classification output) OR the rendered ground being under the ocean's surface. The second exists because WBID was classified from the uncurved heightmap while the mesh renders the curved one. Outside the crater those agree exactly — the curve is identity at sea and monotonic, so Apply(raw) < sea iff raw < sea. Inside it they do not: the carve lerps two different bases toward one target (classify from raw, rendered from Apply(raw), and Apply(raw) < raw in the lowland band), so the rendered surface sinks faster and leaves a ring rendering below the waterline that WBID still calls dry — 375,824 px on the C1 seed, all of it inside the carve. The second clause tests the height the mesh actually uses against the ocean body's own level from WBTB, so the runtime still derives nothing, and by the identity above it can only ever fire inside the carve. A body the table does not know leaves the column dry rather than guessing a level. The level is scaled by the same HEIGHT_SCALE as the terrain, so the sheet and the seabed cannot drift apart. Depth for shading is taken from blueprint heights, not rendered geometry — the terrain render clamps its floor at Y = 2, which would otherwise flatten every deep-ocean column to one value. Each run logs what it drew ([Server] Water at rest: …).

• Surface height per column (GetExactSurface) — the blueprint height scaled into the chunk's usable vertical band, then modified by any road carving.

• Density per voxel — (y − surfaceY) normalised by the local slope, giving a signed distance to the surface. Positive above, negative below.

• Block IDs per voxel via BiomePalette, plus the per-column data the renderer needs.

• Hands the finished chunk to a ChunkRenderer.

Road carving

All four tiers carve, each with its own character (widest and smoothest for highways, narrow and terrain-hugging for trails — values in Constants.cs).

For each column, the carve finds the nearest road whose shoulder actually reaches it — not simply the nearest road, since tiers have different reach and a nearby footpath must not shadow a highway still covering the column. It then reads the roadbed height at the closest point along that segment, blending between a straight ramp between the segment's endpoints ("holds a grade") and the terrain directly beneath ("hugs the land") according to the tier.

Inside the road radius the column is flattened to that height and flagged with the tier's surface material; out to the shoulder radius it eases back to natural ground with a smoothstep.

HeightAtPixel samples the heightmap bilinearly — road path points are fractional, and nearest-cell sampling produced a metre-scale staircase along the roadbed.

Not here yet

No chunk streaming or unloading, no collision, no networking, no player. The "server" is currently a node in the same scene as the renderer — the server/client split is structural, not a process boundary.