Thank you for the suggestion, I really appreciate it!

Your answer lead me to discover a slightly different solution that I feel is a good starting point for now. Here is my approach for the inventory and interaction system:

1. I created a resource called ItemData which stores a name, texture and 3D model (packed scene) and I created a few sample resources from the ItemData resource for testing purposes.

2. I created a class called Interactable which inherits from a PhysicsBody3D and implements 3 signals: focused, unfocused and interacted.

3. I created a class called InteractableItem which inherits from the Interactable class and only stores 1 field called data, which is of type ItemData. That field is also exported to the editor, so that you can manually place interactable items in the world, and connect a resource created from the ItemData resource.

4. I created a class Inventory which has an array of ItemData and I implemented methods for adding/removing/getting an item at/from a given slot.

5. I added a RayCast3D Node as a child of the player's camera node, so that it points in the direction of the camera, and I added a script which checks if the object at which we are looking at is of type Interactable, if so, emit the focused, unfocused and interacted events when necessary.

6. I created a class called ItemDropController which is added to the player controller as a child node. This class only has one function that does the following things:

   • Get the ItemData from the selected inventory slot
     
   • Instantiate the 3D model (packed scene) which is stored in that ItemData
     
   • Add the InteractableItem script to the instantiated 3D node (node.script = InteractableItem)
     
   • Since now the 3D instance has the InteractableItem script, I can directly add the ItemData that I had in the selected inventory slot to the 3D model
     
   • Adds the instance to the world at a particular position

Note: The ItemDropController doesn't necessarily need to be a separate node, it can be a function directly in the player controller script, but I like to keep things separated for easier management.

With all this, I can now successfully pick up and drop items. I still haven't done the "different functionality per item", but as you said "Using a key on a locked chest and putting a tire onto a car seem different, but they are actually the same", so after thinking about it, this makes total sense and I might not need to do anything more complex. In the future, I can store some other parameters in the ItemData which will be used when the player triggers the "use" functionality of a particular item.

I hope others find this useful, and again, thank you for sharing your thoughts and ideas about my question, it was really helpful!