getBlockState in unloaded chunk (1.15.2)

[thebear]

So basically what I'm trying to do is to get the BlockState of a block in an unloaded chunk.

I tried to do so by using World::getBlockState() which works fine in loaded chunks, but in unloaded chunks, it returns a BlockState whose block is always VOID_AIR.

As soon as the chunk gets loaded though, it works correctly.

Is there a way to get the BlockState of a block in an unloaded chunk?

[loordgek]

why do you want to do that ?

[Draco18s]

If it is unloaded, it doesn't exist.

 

You can only view loaded chunks.

[thebear]

13 minutes ago, loordgek said:

why do you want to do that ?

The reason I want to do this is, that I'm writing a mod that gets the shortest path to a location.

To be able to find a path, I need to get the blocks.

 

12 minutes ago, Draco18s said:

If it is unloaded, it doesn't exist.

 

You can only view loaded chunks.

Oh that makes sense. If the block isn't loaded, it doesn't have a state.

Is there any way of getting the type of block at some position in an unloaded chunk then?

[Draco18s]

30 minutes ago, thebear said:

Is there any way of getting the type of block at some position in an unloaded chunk then?

Unloaded chunks do not exist. Its not that they don't have a state, they literally, fundamentally don't exist. An unloaded chunk can be in one of three states:

• Never Created
• Created, but not generated (Minecraft has allocated memory, but not run generation, and it is possible for a chunk to be part way through that process)*
• Populated, but saved to disk

There is no way to differentiate between these states.

The only "solution" is to load the chunk.

 

*Technically there are ways to query block states in these chunks, but as their memory is in another thread, it is not safe to do so.

Edited March 16, 2020 by Draco18s

[thebear]

Alright, I solved my problem now. What I did is, I force loaded the chunk with ServerWorld::forceChunk and then got the BlockState with ServerWorld::getBlockState.

[Alpvax]

Be careful when doing that, chunks are unloaded for a reason (reduce memory usage by not keeping all chunks in memory at once). Make sure you unload/unforce the chunk again when you're done. Otherwise your mod will have performance issues on worlds which have been played for a while.