Spawning mobs from a Tile Entity with custom NBT

[Flenix]

Hey guys,

 

I'm currently working on (relatively simple) NPCs for my mod.

I figured the best way for these to be really usable is to have a "spawn pad" which creates and destroys them as required.

 

Players will have to use in-game money (items) in order to "keep" a mob spawned.

 

 

What I want to know right now, is two things;

1. How can I spawn a mob with certain NBT values set? (I can do all the NBT stuff itself, just need to know how to set it on spawn from a block)

2. How would I use NBT to make a mob invincible? (I can see this being very useful on servers for NPCs at spawn who shouldn't be killed )

[Busti]

Just spawn them via your TE and pass any variables to the Entities constructor. Create these variables in the Entity and set them in the constructor by the given ones. And save them as a tag

YourEntity entity = new YourEntity(posX, posY, posZ, various variables); // Various variables you want to have in the Entity and the coordinates of course...
this.worldObj.spawnEntityInWorld(entity); //That spawns the Entity

 

EDIT: just pass a boolean to make them invincible or not... They should automatically be invincible unless you are using the health system.

[MineMaarten]

Or you could create the entity and inject an altered NBT tag in the Entity. Something like:

CustomEntity entity = new CustomEntity(worldObj);
NBTTagCompound tag = new NBTTagCompound();
entity.writeEntityToNBT(tag);//create the base tag
tag.setShort("Health", (short)10);//alter the tag, for instance here the health is changed. Bit devious but it's an example.
entity.readEntityFromNBT(tag);//inject the entity with the altered tag.
worldObj.spawnEntityInWorld(entity);

[Flenix]

Alright, I think I'm still missing something.

 

Right now, I'm setting the data hardcoded in my block class (where the mob spawn code is) just to try and pass it to my entity. Later, I'll be reading it from my Tile Entity but I want to get this bit working first.

 

I've added a couple of println debug checks. The data seems to be there when it initially spawns but is instantly wiped. Any ideas? Below are my block and my entity classes:

 

package co.uk.silvania.cities.core.npc.spawner;

import co.uk.silvania.cities.core.FlenixCities_Core;
import co.uk.silvania.cities.core.blocks.entity.TileEntityFloatingShelves;
import co.uk.silvania.cities.core.npc.EntityBanker;
import net.minecraft.block.BlockContainer;
import net.minecraft.block.material.Material;
import net.minecraft.entity.player.EntityPlayer;
import net.minecraft.nbt.NBTTagCompound;
import net.minecraft.tileentity.TileEntity;
import net.minecraft.util.AxisAlignedBB;
import net.minecraft.world.World;

public class NPCSpawnerBlock extends BlockContainer {

public NPCSpawnerBlock(int id) {
	super(id, Material.iron);
	this.setCreativeTab(FlenixCities_Core.tabCity);
	this.setHardness(2.0F);
	this.setBlockBounds(0.0F, 0.0F, 0.0F, 1.0F, 0.125F, 1.0F);
}

    public AxisAlignedBB getCollisionBoundingBoxFromPool(World par1World, int par2, int par3, int par4) {
        return null;
    }

@Override
public TileEntity createNewTileEntity(World world) {
	return new NPCSpawnerEntity();
}

@Override
public int getRenderType() {
	return -1;
}

    @Override
    public boolean onBlockActivated(World world, int x, int y, int z, EntityPlayer player, int i, float j, float k, float l) {
    	NPCSpawnerEntity tile = (NPCSpawnerEntity) world.getBlockTileEntity(x, y, z);
    	
	if (!world.isRemote) {
    	if (tile != null) {
			EntityBanker banker = new EntityBanker(world);
			NBTTagCompound nbt = new NBTTagCompound();
			banker.writeEntityToNBT(nbt);
			//For now, just hard-coding some test values to get the NBT block -> mob working.
			nbt.setBoolean("wander", false);// tile.wander);
			nbt.setString("playerName", "Blah" );//tile.playerName);
			nbt.setInteger("despawnTime", 12345);//tile.despawnTime);
			nbt.setInteger("heldID", 6);//tile.heldID);
			nbt.setInteger("helmetID", 7);//tile.helmetID);
			nbt.setInteger("chestID", ;//tile.chestID);
			nbt.setInteger("legsID", 9);//tile.legsID);
			nbt.setInteger("bootsID", 10);//tile.bootsID);
			nbt.setBoolean("entityLocked", true);//tile.entityLocked);
			nbt.setBoolean("entityInvincible", true);//tile.invincible);
			banker.readEntityFromNBT(nbt);
			//Ignore this bit - it doesn't need to be passed to the mob.
			banker.posX = x;
			banker.posY = y;
			banker.posZ = z;
			System.out.println("The offset values are: X:" + tile.offsetX + " Y:" + tile.offsetY + " Z:" + tile.offsetZ);
			banker.setLocationAndAngles((double)x + tile.offsetX, (double)y + tile.offsetY, (double)z + tile.offsetZ, 0.0F, 0.0F);
			banker.onSpawnWithEgg(null);
			world.spawnEntityInWorld(banker);
    	}
    	return true;
	} else {
		return false;
	}
    }

@Override
public boolean isOpaqueCube() {
	return false;
}

@Override
public boolean renderAsNormalBlock() {
	return false;
}
}

 

package co.uk.silvania.cities.core.npc;

import co.uk.silvania.cities.core.CoreItems;
import co.uk.silvania.cities.core.FlenixCities_Core;
import co.uk.silvania.cities.core.NBTConfig;
import co.uk.silvania.cities.core.npc.ai.NPCAITempt;
import co.uk.silvania.cities.core.npc.spawner.NPCSpawnerEntity;
import net.minecraft.client.Minecraft;
import net.minecraft.entity.EntityAgeable;
import net.minecraft.entity.EntityLiving;
import net.minecraft.entity.IMerchant;
import net.minecraft.entity.INpc;
import net.minecraft.entity.SharedMonsterAttributes;
import net.minecraft.entity.ai.EntityAIControlledByPlayer;
import net.minecraft.entity.ai.EntityAIFollowOwner;
import net.minecraft.entity.ai.EntityAIFollowParent;
import net.minecraft.entity.ai.EntityAIHurtByTarget;
import net.minecraft.entity.ai.EntityAILookIdle;
import net.minecraft.entity.ai.EntityAIMate;
import net.minecraft.entity.ai.EntityAIOwnerHurtByTarget;
import net.minecraft.entity.ai.EntityAIOwnerHurtTarget;
import net.minecraft.entity.ai.EntityAIPanic;
import net.minecraft.entity.ai.EntityAISwimming;
import net.minecraft.entity.ai.EntityAITargetNonTamed;
import net.minecraft.entity.ai.EntityAITempt;
import net.minecraft.entity.ai.EntityAIWander;
import net.minecraft.entity.ai.EntityAIWatchClosest;
import net.minecraft.entity.monster.EntitySpider;
import net.minecraft.entity.passive.EntityAnimal;
import net.minecraft.entity.passive.EntityTameable;
import net.minecraft.entity.player.EntityPlayer;
import net.minecraft.inventory.IInventory;
import net.minecraft.item.Item;
import net.minecraft.item.ItemStack;
import net.minecraft.nbt.NBTTagCompound;
import net.minecraft.util.DamageSource;
import net.minecraft.util.ResourceLocation;
import net.minecraft.village.MerchantRecipe;
import net.minecraft.village.MerchantRecipeList;
import net.minecraft.world.World;

public class EntityBanker extends EntityAnimal {

boolean wander;

public EntityBanker(World par1World) {
	super(par1World);
	this.getNavigator().setAvoidsWater(true);
	this.setSize(0.6F, 1.8F);
        this.isImmuneToFire = false;
	float var2 = 0.25F;
        this.tasks.addTask(0, new EntityAISwimming(this));
        this.tasks.addTask(1, new NPCAITempt(this, 1.1D, CoreItems.note10000.itemID, false));
        this.tasks.addTask(2, new NPCAITempt(this, 1.0D, CoreItems.note5000.itemID, false));
        this.tasks.addTask(3, new NPCAITempt(this, 0.9D, CoreItems.note2000.itemID, false));
        this.tasks.addTask(4, new NPCAITempt(this, 0.8D, CoreItems.note1000.itemID, false));
        this.tasks.addTask(5, new EntityAIPanic(this, 0.38F));
        this.tasks.addTask(6, new EntityAIMate(this, var2));
        this.tasks.addTask(7, new EntityAIFollowParent(this, 0.28F));
        this.tasks.addTask(8, new EntityAIWander(this, var2));
        this.tasks.addTask(9, new EntityAIWatchClosest(this, EntityPlayer.class, 6.0F));
        this.tasks.addTask(10, new EntityAILookIdle(this));
}

@Override
public boolean interact(EntityPlayer player) {
	//Right now this is just here so I can right-click the mob and printline what his NBT is as an in-game check.
	player.openGui(FlenixCities_Core.instance, 0, worldObj, 0, 0, 0);
	NBTTagCompound nbt = new NBTTagCompound();
	readEntityFromNBT(nbt);
	return true;
}

@Override
public void writeEntityToNBT(NBTTagCompound nbt) {
        super.writeEntityToNBT(nbt);
        nbt.setBoolean("wander", true);
}

@Override
public void readEntityFromNBT(NBTTagCompound nbt) {
        super.readEntityFromNBT(nbt);
	boolean wander = nbt.getBoolean("wander");
	boolean locked = nbt.getBoolean("entityLocked");
	boolean invincible = nbt.getBoolean("entityInvincible");
	String playerName = nbt.getString("playerName");
	int despawnTime = nbt.getInteger("despawnTime");
	int heldID = nbt.getInteger("heldID");
	int helmetID = nbt.getInteger("helmetID");
	int chestID = nbt.getInteger("chestID");
	int legsID = nbt.getInteger("legsID");
	int bootsID = nbt.getInteger("bootsID");
	System.out.println("NBT values are set as follows:");
	System.out.println("Wander: " + wander);
	System.out.println("Locked: " + locked);
	System.out.println("Invincible: " + invincible);
	System.out.println("Player Name: " + playerName);
	System.out.println("Despawn Time: " + despawnTime);
	System.out.println("Held ID: " + heldID);
	System.out.println("Helmet ID: " + helmetID);
	System.out.println("Chest ID: " + chestID);
	System.out.println("Legs ID: " + legsID);
	System.out.println("Boots ID: " + bootsID);
}

public boolean isAIEnabled() {
	return true;
}

protected void applyEntityAttributes() {
	super.applyEntityAttributes();
		this.getEntityAttribute(SharedMonsterAttributes.maxHealth).getBaseValue(); 
}

protected String getLivingSound() {
	return "mob.glog.say";
}

protected String getHurtSound() {
	return "mob.glog.say";
}

protected String getDeathSound() {
	return "mob.glog.death";
}

protected void playStepSound(int par1, int par2, int par3, int par4) {
	this.worldObj.playSoundAtEntity(this, "mob.glog.step", 0.15F,  1.0F);
}

protected int getDropItemId() {
	return CoreItems.note1000.itemID;
}

public EntityAgeable createChild(EntityAgeable var1) {
	return null;
}
}

 

Notice anything I've done incredibly wrong there?

 

[Flenix]

Anyone got any ideas?

[GotoLink]

IEntityAdditionalSpawnData that would help syncing the things at spawn time.

[TheGreyGhost]

Hi

 

Is there any particular reason that your writeEntityToNBT doesn't add most of your member variables to the NBT (compared with readEntityFromNBT)?

 

Perhaps part of the problem is that you are creating your entity on the server side, but the client side copy is not getting all your extra information because it's not being transmitted in the spawn packet.

 

That's where GotoLink's suggestion comes in, because Forge transmits extra information about your entities from server to client if you use IEntityAdditionalSpawnData.

 

public class EntityBanker extends EntityAnimal implements IEntityAdditionalSpawnData

 

Never used it myself.

 

Entity already has a flag called Entity.invulnerable which might be what you are looking for.

 

-TGG

[Flenix]

Hi

 

Is there any particular reason that your writeEntityToNBT doesn't add most of your member variables to the NBT (compared with readEntityFromNBT)?

 

Perhaps part of the problem is that you are creating your entity on the server side, but the client side copy is not getting all your extra information because it's not being transmitted in the spawn packet.

 

That's where GotoLink's suggestion comes in, because Forge transmits extra information about your entities from server to client if you use IEntityAdditionalSpawnData.

 

public class EntityBanker extends EntityAnimal implements IEntityAdditionalSpawnData

 

Never used it myself.

 

Entity already has a flag called Entity.invulnerable which might be what you are looking for.

 

-TGG

 

I don't think client/server sync is the issue here. The NBT is printing to console as default java values (0 ints, empty strings etc) on both the client and server. I'll research the AdditionalSpawnData thing though and see what it turns up

[Flenix]

It looks like that is used more for things like texture changes and visible differences. Right now everything I'm setting is supposed to be read server-side too, so I don't think that's going to really help at all...

 

Anyone got any other ideas?