New Minecraft Map Format 'Anvil' Coming

Posted in minecraft

Jeb announced today that he's been working on a new map format for Minecraft. Codenamed ‘Anvil' the map format was created to support more block types and also to modify the maximum map height.

In a nutshell the new format opens the door for:

• Up to 4000 block types
• Map heights up to 256

To use the new map format, old worlds need to be converted into the new anvil format. You don't need to worry though, the next Minecraft snapshot will automatically convert worlds to the new format for you. The old version of your world (McRegion) is copied in the save folder in case you need it for some reason.

For mod developers and adventure map designers, Jeb has created a standalone map converter program which you can download below.

Download Jeb's world converter for new map format (convert old McRegion to Anvil)

List of new map format changes – Anvil

• Maximum build height has been increased to 256 (it was 128)
• Empty sections of the world are not loaded into memory (performance improvements)
• Block ids have been increased to 4096 (was 256) by adding a 4 bit data layer (similar to how meta data is stored). Minecraft now supports up to 4000 blocks!!
• Block ordering have been changed from x/z/y to y/z/x in order to improve compression
• Packets for sending chunks have been updated (a full 128-high chunk is smaller than the old format, and a chunk with lots of empty space is much smaller)
• Biomes are saved per x/z column, which means they can be altered by tools