Can someone explain how/when chunk unloading occurs?

[MrChoke]

I'd like to understand more about how chunk unloading occurs.  Take for example some custom mobs that are moving around under new AI I wrote.    I have them set to never despawn.  But I am assuming they will *pause* their movement when the chunk unloads and resume when the chunk comes back.  Can someone explain how that works?  

 

Thanks.

[Draco18s]

Yes, they "pause" because the chunk they are in ceases to exist (and thus, so do they). All* data is serialized and when the chunk loads again that data is deserialized and everything ends up in the same state that it was left in.*

 

*Note: Not literally all data is serialized, eg. pathing information is not and is instead recomputed when needed again.

[MrChoke]

3 minutes ago, Draco18s said:

Yes, they "pause" because the chunk they are in ceases to exist (and thus, so do they). All* data is serialized and when the chunk loads again that data is deserialized and everything ends up in the same state that it was left in.*

 

*Note: Not literally all data is serialized, eg. pathing information is not and is instead recomputed when needed again.

Ok, good to know that it reads/writes to file.  Do you know when a chunk unloads?

 

[Animefan8888]

15 minutes ago, MrChoke said:

Do you know when a chunk unloads?

If it is not being manually kept loaded, ie spawn chunks or chunk loader. Then once they are a distance away from the player they unload, in singleplayer it is the render distance (I believe) in multiplayer it's a "render distance" that is specified in the server.properties file.

[MrChoke]

48 minutes ago, Animefan8888 said:

If it is not being manually kept loaded, ie spawn chunks or chunk loader. Then once they are a distance away from the player they unload, in singleplayer it is the render distance (I believe) in multiplayer it's a "render distance" that is specified in the server.properties file.

OK, yeah, read on the wiki, it says render distance.  So chunk loaders, I see a ChunkLoader class in the minecraft code.  Do we use that to keep chunks loaded or does Forge have some other way?

 

Thanks.

[Cadiboo]

3 hours ago, Animefan8888 said:

If it is not being manually kept loaded, ie spawn chunks or chunk loader. Then once they are a distance away from the player they unload, in singleplayer it is the render distance (I believe) in multiplayer it's a "render distance" that is specified in the server.properties file.

I believe it’s the “render distance” + 2, I could be wrong as I can’t remember where I got this information from though

[Animefan8888]

2 hours ago, MrChoke said:

OK, yeah, read on the wiki, it says render distance.  So chunk loaders, I see a ChunkLoader class in the minecraft code.  Do we use that to keep chunks loaded or does Forge have some other way?

 

Thanks.

I believe there is a class called ForgeChunkLoader or ForgeChunkManager? That allows you to do something with them. I'm not really sure.