Solved Spawn invisible glowing shulker with NMS

Will it be persistent? Unless you dont need it there everytime a simple spawn and some packet work is much easyer

 

Here's a little example:

Code (Java):

final World world = ...; // You'll need to get a handle to the NMS-world
final EntityShulker shulker = new EntityShulker(EntityTypes.SHULKER, world); // instanciate the entity (in this case, the shulker)

final Location loc = ...; // where to spawn the shulker at
shulker.setLocation(loc.getBlockX() + 0.5, loc.getBlockY(), loc.getBlockZ() + 0.5, 0, 0); // set it's location. In this example, I used the player location so I want to add 0.5 to x-and z in order to place the shulker on top of a block
shulker.setInvisible(true); // set the shulker invisible
shulker.h(true); // and glowing
// all of these use the DataWatcher-object. You can directly interface it using shulker.getDataWatcher().set(obj, value)
// for the case of a flag, use shulker.setFlag(int i, boolean flag)
// for example, i=5 is responsible for the invisibility, i=6 is responsible for glowing

PacketPlayOutSpawnEntityLiving packetSpawn = new PacketPlayOutSpawnEntityLiving(shulker); // instanciate the spawn-packet
PacketPlayOutEntityMetadata packetMetadata = new PacketPlayOutEntityMetadata(shulker.getId(), shulker.getDataWatcher(), true); // instanciate the metadata-packet that takes the DataWatcher as an argument

final PlayerConnection playerConnection = player.playerConnection; // get the PlayerConnection, note that player is the NMS-player
playerConnection.sendPacket(packetSpawn); // and finally send the spawn packet
playerConnection.sendPacket(packetMetadata); // and the metadada-packet

 

Unfortunately, the head has to be there, that's just the way the client renders that.
To get rid of the shulker, you'll have to send this:

Code (Java):

PacketPlayOutEntityDestroy destroyPacket = new PacketPlayOutEntityDestroy(shulker.getId());

You'll probably have to store the id somewhere to despawn the right shulker, it's unique for every entity

 

I have never done this (since I try to avoid working with packets as much as possible due to problem pointed out in the third question) so I can only repeat what I have heard/seen other people do:

1) Use ProtocolLib
2) Use Reflection to access the correct Packets
3) Provide an interface (by that I don't necessarily mean a Java-interface) for every distinct version

 

If you just want to display a glowing square, you can try applying it to an invisible fallingblock ?