In the Spawn Object packet, additional metadata about the spawned entity may be provided. The length and contents of this extra data depend on the type of object being spawned. No matter what, the server must send at least one integer to the client, although 0 is a valid value. If a number other than zero is provided (for all entities), the following data is appended to the end of the object data (as of 15w31a, protocol 49 this data is always required):
| Field name
|
Field type
|
Example
|
Notes
|
| Speed X
|
Short
|
0
|
The speed of the object, same units as Entity Velocity
|
| Speed Y
|
Short
|
0
|
The speed of the object, same units as Entity Velocity
|
| Speed Z
|
Short
|
0
|
The speed of the object, same units as Entity Velocity
|
Meaning of int field
Minecarts (id 10)
The int value itself specifies the minecart's functionality:
| Value
|
Minecart functionality
|
| 0
|
Empty (ride-able) minecart
|
| 1
|
Chest minecart
|
| 2
|
Furnace (powered) minecart
|
| 3
|
TNT minecart
|
| 4
|
Spawner minecart
|
| 5
|
Hopper minecart
|
| 6
|
Command Block minecart
|
Item Frame (id 71)
| Field name
|
Field type
|
Example
|
Notes
|
| Orientation
|
Int
|
3
|
0–3: South, West, North, East
|
Falling Block (id 70)
| Field name
|
Field type
|
Example
|
Notes
|
| Block type
|
Int
|
12
|
(Metadata << 0x10)
|
Splash Potions (id 73)
| Field name
|
Field type
|
Example
|
Notes
|
| Entity ID
|
Int
|
64
|
Potion data value
|
For more information on potion data values, see Data values#Potions.
Fishing Float (id 90)
| Field name
|
Field type
|
Example
|
Notes
|
| Owner
|
Int
|
|
The entity ID of the owner
|
This includes ghast fireballs, arrows, and fishhooks (probably more).
| Field name
|
Field type
|
Example
|
Notes
|
| Entity ID
|
Int
|
64
|
The entity ID of the thrower
|
