fix: center ground under chunks and align player spawn with chunk grid

scripts/game.gd

@@ -38,6 +38,7 @@ var _build_editor: InGameEditor = null
 
 
 var _stream_manager: ChunkStreamManager = null
+var _loaded_chunk_coords: Array[Vector3i] = []
 
 
 func _ready() -> void:
@@ -75,11 +76,75 @@ func _setup_chunk_streaming() -> void:
 	_stream_manager._load_chunk(Vector3i.ZERO)
 
 
-func _on_chunk_loaded(_coord: Vector3i, chunk_scene: Node) -> void:
+func _on_chunk_loaded(coord: Vector3i, chunk_scene: Node) -> void:
 	if chunk_scene is ChunkScene:
 		var cs := chunk_scene as ChunkScene
-		if not cs.world_objects.is_empty() or not cs.tile_layers.is_empty():
-			_hide_default_test_props()
+		_hide_default_test_props()
+		if not (coord in _loaded_chunk_coords):
+			_loaded_chunk_coords.append(coord)
+		_adjust_ground_and_spawn_for_chunks(cs)
+
+
+func _adjust_ground_and_spawn_for_chunks(cs: ChunkScene) -> void:
+	var min_cx := 0
+	var max_cx := 0
+	var min_cy := 0
+	var max_cy := 0
+	for c in _loaded_chunk_coords:
+		min_cx = mini(min_cx, c.x)
+		max_cx = maxi(max_cx, c.x)
+		min_cy = mini(min_cy, c.y)
+		max_cy = maxi(max_cy, c.y)
+
+	var min_x := float(min_cx * Chunk.CHUNK_SIZE_X)
+	var max_x := float((max_cx + 1) * Chunk.CHUNK_SIZE_X)
+	var min_z := float(min_cy * Chunk.CHUNK_SIZE_Y)
+	var max_z := float((max_cy + 1) * Chunk.CHUNK_SIZE_Y)
+
+	var center_x := (min_x + max_x) * 0.5
+	var center_z := (min_z + max_z) * 0.5
+	var size_x := maxf(40.0, (max_x - min_x) + 8.0)
+	var size_z := maxf(40.0, (max_z - min_z) + 8.0)
+
+	var ground := get_node_or_null("Level/Ground") as StaticBody3D
+	if ground != null:
+		ground.position = Vector3(center_x, -0.5, center_z)
+		var shape_node := ground.find_child("CollisionShape3D", true, false) as CollisionShape3D
+		if shape_node != null:
+			var box: BoxShape3D
+			if shape_node.shape is BoxShape3D:
+				box = (shape_node.shape as BoxShape3D).duplicate() as BoxShape3D
+			else:
+				box = BoxShape3D.new()
+			box.size = Vector3(size_x, 1.0, size_z)
+			shape_node.shape = box
+		var mesh_node := ground.find_child("MeshInstance3D", true, false) as MeshInstance3D
+		if mesh_node != null:
+			var box_mesh: BoxMesh
+			if mesh_node.mesh is BoxMesh:
+				box_mesh = (mesh_node.mesh as BoxMesh).duplicate() as BoxMesh
+			else:
+				box_mesh = BoxMesh.new()
+			box_mesh.size = Vector3(size_x, 1.0, size_z)
+			mesh_node.mesh = box_mesh
+
+	var spawn_marker := get_node_or_null("Level/PlayerSpawn") as Node3D
+	var found_spawn: Variant = null
+	for obj in cs.world_objects:
+		if obj.type == "spawn_point" or (obj.properties is Dictionary and obj.properties.get("catalog_id") == "spawn_point"):
+			found_spawn = cs.global_position + Vector3(obj.position.x, 1.5, obj.position.y)
+			break
+
+	if found_spawn != null:
+		if spawn_marker != null:
+			spawn_marker.global_position = found_spawn
+		if not _aligned:
+			_player.global_position = found_spawn
+	elif spawn_marker != null and spawn_marker.global_position.is_equal_approx(Vector3(0, 1.5, 0)):
+		var default_center := Vector3(16.0, 1.5, 16.0)
+		spawn_marker.global_position = default_center
+		if not _aligned:
+			_player.global_position = default_center
 
 
 func _hide_default_test_props() -> void:
@@ -194,6 +259,7 @@ func _close_build_mode() -> void:
 	_player.set_process_unhandled_input(true)
 	_player._refresh_mouse_mode()
 
+	_loaded_chunk_coords.clear()
 	if _stream_manager == null:
 		_setup_chunk_streaming()
 	elif is_instance_valid(_stream_manager):
@@ -273,6 +339,7 @@ func _leave_world() -> void:
 
 ## Close the ENet connection and stop it from calling us back mid-teardown.
 func _teardown_net() -> void:
+	_loaded_chunk_coords.clear()
 	if _stream_manager != null and is_instance_valid(_stream_manager):
 		_stream_manager.clear_all_chunks()
 		_stream_manager.queue_free()