Model.get_node() --> Model.get_node_or_null()

[PGComai]

Changed this function in main and modelcontroller so it won't throw errors when the secondary model is not there.

[copygirl]

I believe the Godot VRM addon may always add a "secondary" node to model loaded through it.

However, it uses get_node instead of get_node_or_null:
https://github.com/V-Sekai/godot-vrm/blob/e15199f980064028bfa4fbee5e70dddb82dd55c3/addons/vrm/vrm_extension.gd#L963-L969

	if vrm_extension.has("secondaryAnimation") and (vrm_extension["secondaryAnimation"].get("colliderGroups", []).size() > 0 or vrm_extension["secondaryAnimation"].get("boneGroups", []).size() > 0):
		var secondary_node: Node = root_node.get_node("secondary")
		if secondary_node == null:
			secondary_node = Node3D.new()
			root_node.add_child(secondary_node, true)
			secondary_node.set_owner(root_node)
			secondary_node.set_name("secondary")

This piece of code results in the following error to be printed:

E 0:00:28:328 vrm_extension.gd:964 @ _import_post(): Node not found: "secondary" (relative to "copygirl_v3_0_1").
<C++ Error> Method/function failed. Returning: nullptr
<C++ Source> scene/main/node.cpp:1975 @ get_node()
vrm_extension.gd:964 @ _import_post()
main.gd:51 @ _load()
main.gd:10 @ _on_files_dropped()

If you're attempting to fix that, this PR would not help. Should be PR'd to the Godot VRM repo instead.

Otherwise, could you explain what problem this PR is supposed to fix?
I do in general agree that get_node_or_null should be used where nodes may not exist.
Maybe there's types of models that don't get this node added, so it could still be useful.

[PGComai]

In my setup Main.gd and ModelController.gd both throw the Node not found: "secondary" error. Maybe I'm building my models wrong, though.

[copygirl]

Okay, I suppose your model has neither animation nor colliders so it doesn't generate the secondary node at all.