I’m working on a Unity project and I’ve run into a frustrating issue with my scriptable object inventories. So, I’ve got two scriptable objects that represent my inventories: one is meant to be the starting inventory which has all the initial items, and the other is the current inventory where the player can add or remove items during gameplay. The idea is that the starting inventory serves as a template for the current inventory, so when the game starts, I copy the values from the starting inventory to the current one.
Here’s the problem: when I modify the lists (specifically the “guns” list) in one of the inventories, the other one gets affected too. For instance, if I add or remove a gun from the current inventory, the starting inventory reflects those changes as well. I thought this was weird, especially since I’m using separate instances for each inventory and trying to ensure they’re independent.
To make things even more confusing, this issue doesn’t just happen while the game is running. If I stop the play mode and check the values in the inspector, I see the changes carried over to the starting inventory, suggesting that there’s some kind of reference issue going on. I’ve double-checked that my scripts are only modifying the current inventory, yet the strange behavior persists.
What makes this particularly problematic is that if a player dies and respawns, they could have items that they shouldn’t have based on the starting inventory. Say they pick up a gun during the game that isn’t supposed to be part of their initial loadout; when they respawn, they end up with that gun because the starting inventory has been altered.
I’ve considered whether this might be a bug in Unity, but I can’t help but feel that I might be missing something fundamental about how scriptable objects work or how I’m managing these inventory lists. Has anyone faced something similar? Any advice on how to prevent these inventories from affecting each other would be super helpful!
Inventory Issue with Scriptable Objects in Unity
Sounds like you’ve hit a classic issue with Scriptable Objects! It can be super confusing, especially when it comes to lists. When you’re dealing with Scriptable Objects, remember that they are reference types, meaning if you have a list (like your “guns” list) in the starting inventory and then you directly use that list in the current inventory, both are pointing to the same data. So when you change one, the other one changes too since they’re referring to the same memory location!
To avoid this, you’ll need to create a deep copy of the list when you initialize the current inventory from the starting inventory. Instead of just copying the reference, make a new list and copy each item over individually.
List currentGuns = new List ();
foreach (Gun gun in startingInventory.guns)
{
currentGuns.Add(new Gun(gun)); // Assuming Gun has a copy constructor or method
}
currentInventory.guns = currentGuns;
Make sure you do this at the start of the game to set up the current inventory. This way, your current inventory is a completely separate instance from the starting inventory.
Also, remember to check if you might have mistakenly assigned the same instance of a list somewhere in your code, which could also lead to this issue. Unity Inspector will also reflect these changes since it shows the reference. If you find yourself still having issues, check if your inventory management script might be unintentionally interacting with both inventories in some way.
Lastly, don’t worry! Many people run into this issue when starting out with Scriptable Objects. Just keep experimenting and asking questions, and you’ll get it figured out!
The issue you’re facing with scriptable objects in Unity is likely due to the way lists are referenced in C#. When you create a list within a scriptable object, it is actually a reference type, meaning that when you assign one list to another (such as when copying your starting inventory to your current inventory), you’re not creating a new independent list; rather, you’re merely pointing both references to the same list in memory. Therefore, any changes made to that list will be reflected across all references to it. To solve this, you’ll need to create a deep copy of the list instead of relying on the default shallow copy that occurs when you assign one list to another.
To implement a proper deep copy, consider creating a custom method that instantiates a new list and copies each item from the original list to the new one. You can use a loop or LINQ to achieve this, depending on your needs. If your inventory items are also scriptable objects, ensure you’re creating new instances of those objects as well rather than just copying references. This way, when you modify the current inventory, it will not affect the starting inventory, and you can safely allow players to pick up or drop items without unwanted side effects when they respawn. Remember to check your designs frequently to ensure you’re working with unique instances wherever necessary.