Make runtime loading compatible with threads ?

[Lertsenem]

Hi ! Maybe this is actually not an issue, but I have not been able to figure a solution yet.

So I'm trying to build a very (very) big map for the player to play in. To avoid gulping too much memory (and also to avoid in-editor freezes when opening Godot ^^"), I'm dividing the map in more manageable chunks of 300×300 tiles. In tiled I can then use the world feature to stitch those chunks together.

In Godot I built a Node which is able to read info from the world file, and load neighboring chunks when needed, using YATI runtime importer. It works, but with a minor issue : the import operation takes quite some time and freezes the main thread for about 2 seconds when loading a new chunk, which is very annoying from the player perspective.

To solve this issue, I tried using Threads thusly :

var t = Thread.new()
var c = load_map.bind(m)
t.start(c)

with load_map being :

func load_map(filename):
    var map_scn = Importer.import("res://maps/%s" % filename)
    map_scn.name     = filename
    map_scn.position = Vector2(map["x"], map["y"])
    maps_parent.add_child.call_deferred(map_scn.duplicate())

Unfortunately this approach does not work, and the entire game freezes with error such as :

E 0:00:22:0692   TilemapCreator.gd:273 @ handle_layer(): This function in this node (TileMap) can only be accessed from either the main thread or a thread group. Use call_deferred() instead.
E 0:00:22:0707   TilemapCreator.gd:598 @ create_map_from_data(): This function in this node (level) can only be accessed from either the main thread or a thread group. Use call_deferred() instead.
E 0:00:22:0707   TilemapCreator.gd:486 @ create_polygons_on_alternative_tiles(): This function in this node (level) can only be accessed from either the main thread or a thread group. Use call_deferred() instead.

(of course I tried using call_deferred() as suggested, to no avail).

Now my understanding is that these errors mean the runtime import is not Thread safe, and so I should not use it with Threads. But now I'm all out of ideas on how to tackle my problem, which is why I'm coming here. :]

• Is there a way to make the runtime import Thread-safe?
• Is there another preferred solution I'm not seeing for this kind of issue?

[Kiamo2]

• Is there a way to make the runtime import Thread-safe?

Unfortunately that's beyond my restricted Godot knowledge (others to the rescue...?)

• Is there another preferred solution I'm not seeing for this kind of issue?

Same ...