How it's built

The world

One procedural island. There are no terrain or texture downloads; the only models are four small Kenney props. Everything that has to agree between the terrain, the scenery, the gameplay and the scenario cameras lives in one layout file.

The `drone-island` scenario: the island from 700 m out. The village and pier are on the south shore, the jungle hill rises to the north-west.

#Layout

src/world/layout.js is hand-placed, in metres, with y up, sea level at 0 and north towards −Z.

Feature	Values
Island	Mean shoreline radius 235 m; peak 92 m high at (−30, −45); sea floor down to −42 m
Village	On the south shore round (38, 168): 13 stilt houses, two market stalls, a gazebo
Pier	Runs south from the beach at x = 70, from z = 204 to 318 (114 m); 3.2 m wide, deck 2.25 m above the sea, lamps every 16 m; a 9 m wide head over the last 18 m
Boat mooring	East side of the pier head, (79.5, 309), bow pointing out to sea
Path	A dirt path, 2.2 m wide, from the jungle hill down through the village to the pier foot
Islets	Five rocky islets offshore with sandy aprons, radius 18–42 m, 16–38 m high
Crabs	Four spots along the south beach

#Terrain

src/world/terrain.js defines the island height analytically: a noisy shoreline (kept calmer along the village arc), the hill, a flattened village terrace, a slightly sunken path, the lagoon shelf with reef patches (kept clear along the pier lane), the drop-off to the deep, and the islets. It's baked once into a 1024² grid covering ±640 m. After that the terrain mesh, NatureGL Water's bathymetry, the grass, the scatter layers and the gameplay all read the same bilinear grid, along with masks for grass, jungle, sand and the path.

src/world/terrainMesh.js turns it into a warped grid that is dense at the island and coarse far out (300 to 480 segments, by tier), plus a flat deep-sea skirt to the horizon. The ground shader adds the colours, wet sand and sea-floor ripples.

#Vegetation

Module	What it builds
`vegetation.js`	Palms and broadleaf jungle trees, instanced in 96 m chunks for frustum culling, with a lighter far LOD beyond 125 m. Palm fronds have fresh, yellowing and dead brown variants. All of it sways with NatureGL Grass's wind.
`undergrowth.js`	NatureGL Grass `ScatterSystem` layers streamed round the camera: ferns, banana plants, bushes, rocks, flowers, and grass tufts and shells on the beach
NatureGL Grass	The grass field itself, on the grass mask, thinner on the trodden village terrace

The tree and scatter density scale with the quality tier.

#Village and props

src/world/village.js builds the stilt houses, market stalls, gazebo, path stones, picket fences, yard clutter (barrels, crates, benches, flower pots, drying nets), a canoe, a picnic table, the pier, lamp posts with swinging lanterns, cloth that flaps in the wind and signs that swing. Most of it is merged into a few draw calls with the MeshBuilder in geometry.js. At night the lamps and windows light up.

src/world/props.js loads four Kenney Pirate Kit models (CC0): a barrel, a crate, a chest and a small rowing boat, from demo/public/models/pirate-kit/. If they fail to load, the game logs a warning and carries on without them.

#Under the sea

Module	What it builds
`reef.js`	Reef rocks and four procedural coral types (staghorn, brain, sea fan, tube sponge) in clumps, plus big coral bommies along the whale's route; instanced in 320 m chunks
`seagrass.js`	About 9 000 instanced sea-grass clumps (scaled by tier) in patchy meadows between 2 and 17 m deep. The same density function tints the sand under them, so they read as dark patches from the drone
`marineSnow.js`	Drifting motes round the camera, only under water

#Wildlife

Module	Behaviour	Count (low → ultra)
`life/birds.js`	A boids flock circling the lagoon; now and then one dives into the sea with a splash and flies back up	16 → 40
`life/crabs.js`	Idle side-steps, flee from you, burrow when cornered and reappear later
`life/sea.js`	Fish schools over the reef, and a humpback cruising the drop-off with schools keeping it company	140 → 600 fish

Scenarios re-seed the birds and crabs and set the sea life to a fixed time, so every run of a scenario looks the same.

#The boat

src/world/boat.js builds the fishing boat procedurally: a lofted hull, a wheelhouse with a raked three-pane windscreen and side windows, wipers, a cabin light, an instrument panel with gauges and switches, a compass binnacle, a wheel and throttle that animate, and chart-plotter and radar screens drawn to canvas textures. See The boat.