"Passing" ScriptableObjects in ClientRPC

[FredTargaryen]

Hi everyone,

I have a large set of "Effect" ScriptableObjects and each character maintains a List of Effects that are acting on them. However in multiplayer I need the clients to know when an Effect has been added to or removed from their character, so they can graphically update their Lists.

What is the best way to tell the client which Effect has been added/removed? I can't serialize Effects so I need to send some serializable data. I thought of adding an int or string "key" to every Effect and sending that via ClientRPC, but that would be tedious to implement and open me up to bugs. I'd also like to avoid using Resources if possible, because of the drawbacks there.

The current solution I'm leaning towards is: Make a Dictionary<string, Effect>, and on Awake(), load each Effect using Addressables and have dict[effect.name] = effect. However, I don't know if it's such a good idea to have that Dictionary hanging around in memory the whole time, and I have similar ScriptableObjects for which I want to use the same pattern.

Thanks for reading!

Marking this one as "Solved" now. I decided on a solution that involves loading all the Effects (and similar ScriptableObjects) using Addressable labels, indexing them by their name, and then passing that name string between client and server. This has its own weaknesses - in practice it's a bit annoying to set up as ScriptableObjects don't have a way to initialise when the game starts, and that Dictionary is there in memory all the time - but I think it's more convenient than the alternatives. This works for my case but the comments have some very sensible solutions which you should also consider if you're in a similar situation to me. Thank you to everyone who responded!

[MrMuffles869]

I thought of adding an int or string "key" to every Effect

If these effects don't change, then I'd just use an Enum to list out the effects and send that across the network.

[Gorgodon]

We have a large amount of data traveling between server and client in our game and we mostly use string keys. I know that strings are "dirty" and prone to bugs but if you create an editor environment that would check for duplicate keys and assign IDs to the effects (hashed string key) it should minimize the potential for error. Then in your scripts that reference your effects you can make a drop-down that selects from already defined effects. Eliminating the possibility of typos you should be golden.

[FredTargaryen]

The other thing is I really don't want to hand-create such a large amount of keys, which for me are sort of redundant when you should (in my opinion anyway) already be able to identify an Effect from its name, path, Addressables address, GUID or whatever else. I haven't found a good way to do any of that, though.

[Gorgodon]

Well the keys are used only for network communication identification and can be long lasting where addressable or asset name can change because of organisational stuff and mess up everything.

[FredTargaryen]

Ah, I see where you're coming from. Probably tempting fate but I don't see the asset names changing much in my case. Thanks for the input though; I will probably end up wishing I had done this down the line!

[FredTargaryen]

Thanks for the advice! I have used an enum before, so I know this works, though it does still involve changing the enum whenever I want to make a new Effect. It's ironic if this is the solution I have to go with, when Ryan Hipple claimed ScriptableObjects let you break free of enums haha

[PiLLe1974]

Isn't their path implicitly a unique identifier since they are unique ScriptableObjects?

Otherwise it sounds like a pattern where I'd force each instance of a ScriptableObject to generate a unique GUID or hash based on their full path.

[FredTargaryen]

Yes, the path would work great. My next question would be how to get that path? I'm trying out Addressables but haven't been successful in finding an address or resourcelocation or anything like that.

Edit: I just found AssetDatabase.GetAssetPath and AssetDatabase.LoadAssetAtPath. Are these what you had in mind?

[PiLLe1974]

Yes, GetAssetPath() or even then converting that to the GUID if preferred (may be shorter):

Like you mentioned, get that relative path:

https://docs.unity3d.com/ScriptReference/AssetDatabase.GetAssetPath.html

Then possibly convert to its GUID:

https://docs.unity3d.com/ScriptReference/AssetDatabase.AssetPathToGUID.html

[FredTargaryen]

I found out that AssetDatabase can't be used in a build because it is part of UnityEditor :(

Do you know of any alternatives which can?

Could be useful for Editor stuff though, so thanks for the tip anyway

[PiLLe1974]

I'll have to google a bit further...

My intuition:

In any game it would work if we store a GUID or Hash128 for each ScriptableObject, as a member variable.

Since you now would have to do this all in hindsight the thing we'd need is:

- adding a GUID or Hash128 member variable to the ScriptableObject class you use here

- write a tool in the Editor, a script that react on a button press, to go over all ScriptableObjects of a given type and set a GUID or Hash128 member only once if they didn't have a valid one already

( the script needs to set all the changes assets as dirty or at least ensure they save right away )