2y ago

Node unique ID for saving and loading

Is there something like a node ID which is specific to that node and will be the same no matter how often I execute the game? That would be super useful for saving and loading games.

9 comments

What is your use case? That would help narrow down a good solution. Node path could likely work. You could also add a uuid or similar (there's an extension that provides a uuid implementation). Might be hacky, but you could tap into this and see if it suits your needs https://docs.godotengine.org/en/stable/classes/class_resourceuid.html
- I want to use this unique value as a key for a dictionary, which will have some data in it (positions, rotations and some custom values)
  
  Is there a reason you don't want to serialize that data with the nodes that use them? Are those values intended to change when the entity isn't loaded into a scene (like a background simulation or something)?
  Seems like adding your own uuid or tapping into the ResourceUid class might be your best option
Node paths are unique and stay consistent across restarts, although I don't know if that's exactly what you're asking for.
- This works really well when you have one large world on which you want to save many different objects, but I would like to have a node unique ID which is unique across the entire project. Otherwise though, a really good call, thank you!
  
  scene name + node path
I've thought about this problem creating a system to save game state. The issue with assigning a UUID works until you have dynamic scenes added to the game at runtime. The nodes in those scenes will all have the same UUID. In the end I ended up just using the paths and saving the fact that the scene that data is being saved for is dynamic. Then the system sees this and re-instances the scene and adds it back to the tree. (A slight adjustment to the path must be made as Godot will create nodes with the at (@) symbol in them, but you can't do that yourself.)
You can see this in action at my demo repo on github.

9 comments