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Cinderwild/scripts/world/terrain.gd

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GDScript

extends Node3D
## Terrain generator — M0 placeholder.
##
## Builds ONE heightmap chunk from deterministic noise, so the world already
## looks like rolling ground rather than a flat plane. This is intentionally
## simple: a single chunk, generated at _ready(). Chunk streaming, biomes and
## server-side determinism (see docs/ARCHITECTURE.md §4) come in later milestones.
##
## The mesh is generated in code (no asset needed) so the project runs the moment
## Godot opens it, with nothing to import.
@export var size: int = 128 # chunk is size x size metres
@export var resolution: int = 96 # vertices per side (higher = smoother/heavier)
@export var height_scale: float = 10.0
@export var noise_seed: int = 1337
func _ready() -> void:
_build()
func _build() -> void:
var noise := FastNoiseLite.new()
noise.seed = noise_seed
noise.noise_type = FastNoiseLite.TYPE_PERLIN
noise.frequency = 0.012
noise.fractal_octaves = 4
var st := SurfaceTool.new()
st.begin(Mesh.PRIMITIVE_TRIANGLES)
var step := float(size) / float(resolution)
var half := size * 0.5
# Build a grid of quads, two triangles each.
for z in range(resolution):
for x in range(resolution):
var x0 := x * step - half
var z0 := z * step - half
var x1 := (x + 1) * step - half
var z1 := (z + 1) * step - half
var p00 := Vector3(x0, _height(noise, x0, z0), z0)
var p10 := Vector3(x1, _height(noise, x1, z0), z0)
var p01 := Vector3(x0, _height(noise, x0, z1), z1)
var p11 := Vector3(x1, _height(noise, x1, z1), z1)
_add_tri(st, p00, p01, p11)
_add_tri(st, p00, p11, p10)
st.generate_normals()
st.generate_tangents()
var mesh := st.commit()
var mi := MeshInstance3D.new()
mi.mesh = mesh
# Simple ground material. Low-poly look = flat-ish colour + lighting does the rest.
var mat := StandardMaterial3D.new()
mat.albedo_color = Color(0.33, 0.45, 0.22) # mossy green
mat.roughness = 0.95
mi.material_override = mat
add_child(mi)
# Collision so the player can walk on it.
var body := StaticBody3D.new()
var shape := CollisionShape3D.new()
var col := mesh.create_trimesh_shape()
shape.shape = col
body.add_child(shape)
add_child(body)
func _height(noise: FastNoiseLite, x: float, z: float) -> float:
return noise.get_noise_2d(x, z) * height_scale
func _add_tri(st: SurfaceTool, a: Vector3, b: Vector3, c: Vector3) -> void:
st.add_vertex(a)
st.add_vertex(b)
st.add_vertex(c)