NBTs

In Minecraft, every block, entities and players are described by a data structure. It is called NBT. NBTs are an extremely simple and efficient structured binary format used by the Minecraft game for a variety of things

Thought Skript, we can manipulate NBTs thanks to the addond Skbee.

Manipulating NBTs allows us to store data directly in the native Minecraft things we are manipulating.

All these transformations are centralized in 3 different files:

1. items/item_nbt

2. blocks/block_nbt

3. entities/entity_nbt

Each file expose functions allowing to store text, numbers and text lists in NBTs. Texts are manupulated though tag functions, Numbers through stat functions, and list through _list functions. They follow this syntax:

• stat: <item|entity|block>_nbt_<get|set|isset|add|delete>_stat

• tag: <item|entity|block>_nbt_<get|set|isset|delete>_tag

• list: <item|entity|block>_nbt_<get|set|isset|delete>_list

Let's illustrate it with examples:

Store text into NBT

set {_entity} to last_spawned_entity
entity_nbt_set_tag({_entity}, "TYPE", "MOB")
set {_type} to entity_nbt_get_tag({_entity}, "MOB"}

Get the value of a NBT tag

set {_entity} to attacker
set {_type} to entity_nbt_get_tag({_entity}, "TYPE")

Determine if a NBT tag exist

set {_entity} to attacker
if entity_nbt_isset_tag({_entity}, "TYPE") is true:
    ....

As we can notice, we have made a tautology. This is normal when using Skript.

NBT Stat

set {_p} to player
set {_hasAttack} to entity_nbt_isset_stat({_p}, "ATTACK") // false
set {_attack} to entity_nbt_get_stat({_p}, "ATTACk") // 0
entity_nbt_add_stat({_p}, "ATTACK", 10) //ATTACK is now 10

If a stat hasn't been initialized, the return value is 0

If we call _add on a non-initialized stat, it will be initialized with the provided value

NBT List

set {_p} to player
entity_nbt_set_list({_p}, "WILL", "BURNING_HEART")
set {_will::*} to entity_nbt_get_list({_p}, "WILL") // "BURNING_HEART"
entity_nbt_add_list({_p}, "WILL", "EARTH")
set {_will::*} to entity_nbt_get_list({_p}, "WILL") // "BURNING_HEART" and "WILL"

NBT on Items

set {_item} to diamond sword
set {_item} to item_nbt_set_stat({_item}, "ATTACK", 10)
item_nbt_add_stat({_item}, "ATTACK", 10)
set {_attack} to item_nbt_get_stat({_item}, "ATTACK") // 10

You might have noticed that manipulating NBTs on item is trickier. Due to a Minecraft limitation, we cannot directly manipulate NBTs of items. To do it, we have to: - Get the current NBT of the item - Add/Set/Delete some tags/list/stat of the NBT - Generate a new item from the modified NBT item_nbt does it for us. We simply have yo reasign the item after calling the edition functions.

set {_item} to diamond sword
set {_item} to item_nbt_set_stat({_item}, "ATTACK", 10)
set {_item} to item_nbt_add_stat({_item}, "ATTACK", 10)
set {_attack} to item_nbt_get_stat({_item}, "ATTACK") // 20

Manipulate Minecraft native NBTs

As said earlier, NBT allows to sotre some data to things in Minecraft. Sometimes, it is usefull to manipulate native Minecraft NBTs.

set {_projectile} to last shot projectile
entity_nbt_set_tag_native({_projectile}, "{NoGravity:1b}") // projectile does not have gravity anymore.