Talk:Technical blocks/Air

About air ItemBlock (Only about Java Edition)
''The block "Air" was not registered as a block until 1.7.2 (13w38b). This means backporting is not a valid way to obtain the air item.''

The function of air block is defining an area where blocks are nonexistent as a empty block. For example, this is save file for your world (I do not know how numerical data of blocks stored, I just made up. This is not information about game level format. I assumed it is a pre-flattening version):

The numbers in the left side are base data, and right side is metadata. (y:70) 0 0 0  0  0  0   ///    0 0 0 0 0 0

(y:69) 0 49 49 49 49 0  ///    0 0 0 0 0 0

(y:68) 0 49 90 90 49 0  ///    0 0 2 2 0 0

(y:67) 0 49 90 90 49 0  ///    0 0 2 2 0 0

(y:66) 0 49 90 90 49 0  ///    0 0 2 2 0 0

(y:65) 0 49 49 49 49 0  ///    0 0 0 0 0 0

(y:64) 3 3 3  3  3  3   ///    0 0 0 0 0 0

(y:63) 3 1 1  3  3  1   ///    0 0 1 0 0 0

(y:62) 1 1 1  3  1  3   ///    1 2 0 0 1 0

(y:61) 1 1 1  1  1  1   ///    1 0 2 1 0 1

In this case, the data indicates that it is a nether portal structure. In base data, id 0 is used for nonexistent base data (this means air block is used in this places).

About metadata: If a block does not exist, also its metadata does not exist. Block 90 means nether portal block, and its metadata is 2 (90:2 block). This means the portal block is tilted to Z axis. Block 49 means obsidian block, which does not have block states and therefore, it does not have metadata.

About item data, 0 is used for nonexistent items. This is the reason why air block does not have any item form (differs from other technical blocks). For example, this is your inventory (I know how it is stored, which uses an NBT tree system. To show the numerical data about items, I will show as a number dump)

The numbers in the left side are base data, middle is item count, right side is metadata. Different data types are seperated by slash.

1  1   0   0   0   3   3   2   1   0  / 1 1 0 0 0 2 3 5 1 0 / 0 1 0 0 0 2 3 0 1 0

5  6   9   8   3   2   10  11  26  15 / 7 4 6 5 2 3 9 8 7 5 / 0 0 0 0 1 0 0 0 0 0

0  0   0   0   0   0   0   0   0   0  / 0 0 0 0 0 0 0 0 0 0 / 0 0 0 0 0 0 0 0 0 0

256 257 259 262 275 258 259 287 326 3 / 1 1 1 1 1 1 1 1 1 1 / 0 0 0 0 0 0 0 0 0 0

The number "0" is used when referred any type of numerical data is nonexistent or invalid, including item data. Start of numerical id list:

0 - Air 1 - Stone 2 - Grass Block 3 - Dirt 4 - Cobblestone 5 - Planks 6 - Saplings 7 - Bedrock 8 - Flowing Water 9 - Stationary Water 10 -Flowing Lava 11 -Stationary Lava etc.

Technical blocks such as water, lava, fire etc. can be obtained by registering an ItemBlock for it but this excludes air because in Minecraft, "air" means "placeholder of nonexistent block". Umucraft (talk) 16:52, 10 December 2022 (UTC)