Client-side server world info

[Abattoir 0]

Hello.

 

I would like to create an 1.16.4 client-side mod which can store per-world info but I don’t know how can I get any unique info about a world in a server?

I only found the dimension but I would like to add multiworld support so I have to distinguish the worlds.

Thanks for your answer.

[diesieben07 7696]

The client will get a hash of the server's seed, you can use that.

[Abattoir 0]

I don’t find that method.

Can you please explain it more how can I get the server world seed from my client-side mod?

Thanks!

[diesieben07 7696]

21 minutes ago, Abattoir said:

Can you please explain it more how can I get the server world seed from my client-side mod?

You cannot get the server world seed. The client receives a hashed seed (BiomeManager.getHashedSeed), which you can use for identification purposes.

The only way to get this hashed seed is first World#getBiomeManager and then BiomeManager#seed (you'll need reflection for the latter).

[Abattoir 0]

I found that on some servers (like Hypixel) the seed is 0.

What can cause this? Is there any other way to identify the world?

 

Code:

@SubscribeEvent
public static void onPlayerJoin(EntityJoinWorldEvent event) {
    if (Minecraft.getInstance().player == null || event.getEntity() != Minecraft.getInstance().player) {
        return;
    }

    BiomeManager biomeManager = Minecraft.getInstance().player.getEntityWorld().getBiomeManager();
    Long seed = ObfuscationReflectionHelper.getPrivateValue(BiomeManager.class, biomeManager, "field_226833_b_");

    if (seed == null) {
        return;
    }

    System.out.println("SEED: " + seed); // DEBUG
}

Edited January 25 by Abattoir

[diesieben07 7696]

44 minutes ago, Abattoir said:

I found that on some servers (like Hypixel) the seed is 0.

What can cause this?

Then the server doesn't send the hashed seed.

 

45 minutes ago, Abattoir said:

Is there any other way to identify the world?

You can use the server IP, I guess.

 

45 minutes ago, Abattoir said:

 

@SubscribeEvent
public static void onPlayerJoin(EntityJoinWorldEvent event) {
    if (Minecraft.getInstance().player == null || event.getEntity() != Minecraft.getInstance().player) {
        return;
    }

    BiomeManager biomeManager = Minecraft.getInstance().player.getEntityWorld().getBiomeManager();
    Long seed = ObfuscationReflectionHelper.getPrivateValue(BiomeManager.class, biomeManager, "field_226833_b_");

    if (seed == null) {
        return;
    }

    System.out.println("SEED: " + seed); // DEBUG
}

• ClientPlayerNetworkEvent.LoggedInEvent woudl be a much better choice here.
• Do not use getPrivateValue. Use findField and store the Field in a static final field.

[Abattoir 0]

I found a mod called Xaero's Minimap which can store waypoints per world.

 

 

Do you know how can it recognise the server worlds or it uses a custom method?

Edited January 25 by Abattoir

[diesieben07 7696]

It uses the server IP I'm guessing.

[Abattoir 0]

Okay.

And what can I do with singleplayer worlds?

They have any unique thing I can get?