Spawning Entities

Basics

Overview

Spawning entities consists of 3 steps:

• Making the variable storing the future entity
• Modifying the attributes of the entity
• Spawning the entity

Making a variable to store the entity

Example

level is just a placeholder, in your code it needs to be defined, for many events you can use event.level in place of level and it will work

You can create a entity from a block instead of level, and this is often preferred to learn that, scroll to that section afterward

let myEntity = level.createEntity("cow")

Breaking down the example

• let
  • Indicate that we are making a new variable and get the game ready to store it.
  • Not required in 1.16.
• myEntity
  • This is the name of the variable.
  • Can be anything you chose that is a-Z,0-9 without spaces (you know like any other variable).
• =
  • sets myEntity to what is about to follow.
• level
  • This is any level object that you choose.
  • This can be obtained numerous ways and will depend on what you are trying to do.
  • In many events you can use event.level to get the level.
  • Note: this is a LevelJS object, not a minecraftLevel object.
    • minecraftLevel.asKJS() returns a LevelJS.
• .
  • The dot operator either
    • Gets a property of the object.
    • Calls a method of the object.
    • Calls a beaned method of the object.
  • In this case it is used to call the method createEntity. You can tell because the following parenthesis mean its a method.
• createEntity(...)
  • As mentioned above is the method called by the dot operator
• "cow"
  • this is the name of the entity
  • "minecraft:cow" or "create:potato_projectile" are also valid
    • in fact when you put a resource location without a prefix, then minecraft: will be assumed.

Modifying the properties

Example

myEntity.x = 0
myEntity.y = 69
myEntity.z = 0
myEntity.motionY = 0.1
myEntity.noGravity = true

Breaking Down the Example

• myEntity
  • Gets the variable that was made earlier.
• .
  • The dot operator mentioned earlier.
• motionY = 0.1
  • Instead of being a method, like last time, this is a beaned method.
  • This means that there exists a method setMotion and under the hood it runs setMotionY(0.1) that is automatically called with this code.
  • In this case it sets the motionY property of the entity.

  • You many not change arbitrary bits of NBT this way! Only bits that there is a method for. In the example, all of the lines are just running beaned methods. However, you can do it with a different method, listed in a different section below.

Spawning the entity

Example

myEnity.spawn()

With understanding from the previous sections you should be able to figure out what this does.

It get myEntity, then calls the method .spawn().

This spawn() method creates the entity in the world.

Note: myEntity is still a variable! So you may not use let myEntity again within the scope! However this variable is still linked to the entity so calling myEntity.motionY = 0.1 will still set the vertical motion of the entity. (This can be a useful thing, but bad if you are unaware)

Creating the entity from a block

You can also call createEntity from a block! This is handy if you want to spawn the entity in the position of a block.

let myEntity = block.createEntity("cow")

Again, block is just a place holder, you will need to change it to something else like maybe event.block for your code to work!

This does not spawn the entity in the center of the block, it just sets the entity's coordinates to that of the block, thus being misaligned

This code offsets the entity to be in the center of the block.

let myEntity = block.createEntity("cow")
myEntity.x+=0.5
myEntity.y+=0.5
myEntity.z+=0.5

Setting NBT

You can set the NBT to whatever you want! It's recommend using mergeFullNBT to do this.

myEntity.withNBT({VillagerData:{}})

myEntity.fullNBT.VillagerData = {} will not work, because .fullNBT is a beaned method, not a property! The only thing that the beaned method lets do is to be able to use let nbt = myEntity.fullNBT to set a variable to NBT to be read or use myEntity.fullNBT = {} to set all of it at once.

Note it is fullNBT not nbt, because kubejs uses nbt for a different purpose. A bit confusing, but it is what it is.

Item Entities

There are two ways to create item entities in KubeJS.

popItem

If you want to easily create the item from a certain block then you can use the popItem method.

Example

block.popItem('minecraft:diamond')

The item can be an Item.of() instead if you wish

createEntity("item")

Creating an item entity with a little more control be done identically to any other entity, except you get a couple more methods.

Example

let itemEntity = block.createEntity("item")
itemEntity.y+=0.8
itemEntity.x+=0.5
itemEntity.z+=0.5
itemEntity.item = Item.of("encahanted_book").enchant("thorns",2)
itemEntity.item.count = 1
itemEntity.pickupDelay = 600
itemEntity.noGravity = true
itemEntity.motionY = 0.08
itemEntity.spawn()

In this example

• the .item beaned method is used to set the item of the item stack (Required)
• the .pickupDelay beaned method is used to set the pickup delay (Optional)

Examples

Spawns an endermite when braking dirt with a 5% chance

onEvent("block.break", event => {
	if (event.block.id != "minecraft:dirt" || Math.random()  > 0.05) return
  	//only if its dirt and only has 5% chance
  	let myEndermite = event.block.createEntity("endermite")
  	myEndermite.x += 0.5
  	myEndermite.y += 0.5
  	myEndermite.z += 0.5
  	myEndermite.spawn()
})

Turns gravel to sand and drops clay when right clicked with flint

onEvent('block.right_click', event => {
  if (event.block.id == 'minecraft:gravel' && event.item.id == 'minecraft:flint') {
    event.block.set('sand')
    event.item.count--
    event.block.popItem('clay')
  }
})

Overrides enchanting table behavior when clicking on it with an item in you hand. Instead will make the item float up a while, then fall back down.

onEvent('block.right_click', event => {
    if (event.block.id !='minecraft:enchanting_table') return
    if (event.item.count == 0) return
  	event.cancel()
    let item = event.item.copy()
    //if did not use .copy() the item would still be referencing the one in the hand, so setting the count to 1 would set the count in the hand to 1
    item.count = 1
  	event.item.count--
  	
    let itemEntity = event.block.createEntity('item')
    itemEntity.y+=0.8 // on the top of the encahnting table, not in it
    itemEntity.x+=0.5
    itemEntity.z+=0.5
    itemEntity.item = item
    itemEntity.item.count = 1
    itemEntity.pickupDelay = 100
    itemEntity.noGravity = true
    itemEntity.motionY = 0.08
    itemEntity.spawn()
  	
  	function callback (i) {
    	//changes the scope of itemEntity (otherwise if used 2 times in a row within 5 seconds, problems would occur)
    	event.server.scheduleInTicks(100, callback => { // this code runs 5 seconds later
    		i.noGravity = false
    	})
    }
  	callback(itemEntity)
})