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View Chunks

Unloaded Chunks

UnloadedView Chunks or Cached Chunks (but officially called unloadedview chunks) are chunks that have most but not all functionality disabled within them. These chunks are not simulated and cannot process things like block updates and pending ticks. There are three main natural instances of unloaded chunks in a Minecraft world, Spawn Chunks, Chunks in your render distance, and the "perma-cache" phenomenon. These chunks do process some events however and knowing what does and does not work will help you be able to interact with these chunks in much more confidence.

Where do they come from

They come from only these sources:

    End Gateway Pairing  Player Render Distance Spawn Chunks Maps Various Commands
      /teleport /execute detect /structure /spreadplayers /setblock /fillblocks /clone /testforblock /testforblocks Lighting Updates. Ticking Areas

      Green means the view region is deconstructed after use. Yellow means the area is deconstructed after the owner disconnects. Red means the area is never deconstructed until the world restarts.

      What Works In Them

      The things we know to work in unloaded chunks:

      • Redstone circuit structure
      • Capacitors (E.g, Redstone Torches, Repeaters, Comparators)
      • Redstone Dust
      • Global Entities (Player Owned Projectiles, Ender Dragon, fireworks, lightning)
      • Block state changes from a wind charge
      • Sculk Spread
      • Block Creation
      • Tripwire
      • Target Block
      • Pressure Plate
      • Damaging/Killing Entities (Non-Global Entities will not be fully dead/deleted until simulated)
      • Artificial Entity Spawning
      • Breeze Projectile Redirection
      • Pending Tick Scheduling (Not execution)
      • Wind Charging effect.
      • Weaving Effect

      Although Observers are a "Pulse Capacitor" they cannot fire in unloaded chunks due to their reliance on pending ticks.

      Since tridents are player-owned projectiles, they can fall through the world if they spawn in an unloaded chunk before the chunk’s block collision map is initialized especially when the world is running slowly. Grindstones are used to combat this.

      Perma-CachingHow it works under the hood

      Perma-Caching is an unexplained phenomenon that happens when a player spends enough time in a given part of their world. The game will generate a seemingly random arrangement of chunks around the area that will not become unprocessed and stay in the unloaded state. This phenomenon does not seem to go away with relog or waiting.  

      Why "Unloaded Chunks"

      We call them unloaded chunks because, in game, functions like these refer to them as unloaded chunks. This allows us to keep consistency with what the game developers at Mojang refer to them as internally. We do this because it helps us know what to look for when learning about something related to them.

      void Dimension::transferEntityToUnloadedChunk(Actor& actor, LevelChunk* oldChunk)

      These chunks are represented by the hex values 0x0000 through 0x0008 but each valuefunctionality is a different stateproduct of an unloaded chunk.