ceiling ???

Scripts/Space/SpaceRegion.gd

@@ -10,6 +10,7 @@ class_name SpaceRegion
 @export var height: float = 100.0
 @export var wall_texture: Texture2D
 @export var floor_texture: Texture2D
+@export var ceiling_texture: Texture2D
 
 
 func generate_geometry(space: Space) -> Node3D:
@@ -43,6 +44,12 @@ func _generate_geometry(space: Space, looked_from_inside: bool) -> Node3D:
 		floor_material.albedo_texture = floor_texture
 		mesh.surface_set_material(1, floor_material)
 
+		mesh.add_surface_from_arrays(Mesh.PRIMITIVE_TRIANGLES, _generate_ceiling_arrays(space))
+		var ceiling_material := StandardMaterial3D.new()
+		ceiling_material.albedo_texture = ceiling_texture
+		ceiling_material.cull_mode = BaseMaterial3D.CULL_FRONT # todo: Don't require state change
+		mesh.surface_set_material(2, ceiling_material)
+
 	geometry.mesh = mesh
 
 	for child in get_children():
@@ -124,3 +131,27 @@ func _generate_floor_arrays(space: Space) -> Array:
 	arrays[Mesh.ARRAY_TEX_UV] = uvs
 
 	return arrays
+
+
+# todo: Reuse triangulation with the floor
+func _generate_ceiling_arrays(space: Space) -> Array:
+	var triangulation := Geometry2D.triangulate_polygon(self.polygon)
+	var vertices := PackedVector3Array()
+	var uvs := PackedVector2Array()
+	vertices.resize(triangulation.size())
+	uvs.resize(triangulation.size())
+
+	for i in range(triangulation.size()):
+		vertices[i] = Vector3(
+			self.polygon[triangulation[i]].x * space.unit_scale,
+			(elevation + height) * space.unit_scale,
+			self.polygon[triangulation[i]].y * space.unit_scale,
+		)
+		uvs[i] = self.polygon[triangulation[i]] * space.unit_scale
+
+	var arrays := Array()
+	arrays.resize(Mesh.ARRAY_MAX)
+	arrays[Mesh.ARRAY_VERTEX] = vertices
+	arrays[Mesh.ARRAY_TEX_UV] = uvs
+
+	return arrays