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  • A "neighbour" is a IBlockState in-world that is directly adjacent to another "neighbour".
  • It MUST be able to be queried via the 6 EnumFacing directions when calling offset on its BlockPos.


  • Flags are used when setBlockState is called, certain flags to certain things, and its good to know them. (This will be in its own page soon.)

    • Flag 1: Notify neighbours
    • Flag 2: Send to Clients
    • Flag 4: No need to update render
    • Flag 8: Mark for immediate render update (ignored if flag 4 is present)
    • Flag 16: Disable Observers from seeing this block update
  • Forge has marked 1 | 2 as the "default" flag combination when setBlockState.

  • Forge has marked 1 | 2 | 8 as the "default" flag combination when setBlockState that needs to update the main render thread.

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