I have written a simple custom entity extending the Entity base class, and am trying to spawn instances of this entity from one of my custom TileEntities. I have registered my entity in the preInit method of the main mod class like this:

 

int uniqueId = EntityRegistry.findGlobalUniqueEntityId(); 
EntityRegistry.registerGlobalEntityID(MyEntity.class, "myEntity", uniqueId);
EntityRegistry.registerModEntity(MyEntity.class, "myEntity", uniqueId, this, 80, 3, false);

 

But when try to instantiate it using Entity.createEntityByName it always returns null, and if I create an instance myself using "new MyEntity..." and then pass it to World.spawnEntityInWorld, I still get a NullPointerException.

 

How should I go about this? Is there something I'm missing?

Ah, of course...

 

This is my entity class. It hardly does anything but I guess that might be the problem.

package com.vinther.mymod.entity;

import net.minecraft.entity.Entity;
import net.minecraft.nbt.NBTTagCompound;
import net.minecraft.util.AxisAlignedBB;
import net.minecraft.world.World;

public class MyEntity extends Entity
{
    public MyEntity(World world)
    {
        super(world);
this.setSize(1f, 1f);
    }

    @Override
    protected void entityInit() {}

    public void onEntityUpdate()
    {
        super.onEntityUpdate();
        System.out.println(this.posX +", "+ this.posY +", "+ this.posZ);
    }

    public boolean canBeCollidedWith()
    {
        return true;
    }

    @Override
    protected void readEntityFromNBT(NBTTagCompound p_70037_1_) {}

    @Override
    protected void writeEntityToNBT(NBTTagCompound p_70014_1_) {}

    public AxisAlignedBB getCollisionBox(Entity entity)
    {
        return AxisAlignedBB.getBoundingBox(this.posX - this.width / 2f, this.posY - this.height / 2f, this.posZ - this.width / 2f,
                                            this.posX + this.width / 2f, this.posY + this.height / 2f, this.posZ + this.width / 2f);
    }
}

 

And this is the TileEntity where I try to instantiate it.

package com.vinther.mymod.tileentity;

import com.vinther.mymod.MyMod;
import com.vinther.mymod.entity.MyEntity;

import cpw.mods.fml.relauncher.Side;
import cpw.mods.fml.relauncher.SideOnly;
import net.minecraft.entity.Entity;
import net.minecraft.nbt.NBTTagCompound;
import net.minecraft.tileentity.TileEntity;
import net.minecraft.util.AxisAlignedBB;
import net.minecraft.world.World;

public class MyTileEntity extends TileEntity
{
    public MyTileEntity()
    {
        MyEntity entity = new MyEntity(worldObj);
        worldObj.spawnEntityInWorld(entity); // This line throws NullPointerException
    }

    ...

}

Yea, sorry. I edited it in.

Oh.. Silly me. Thank you!

 

But TileEntity doesn't seem to have a good place to init stuff.

For tile entities it is updateEntity(){

}.

 

And that boolean is not required because it is standartly true.

This tile entity doesn't have the boolean for updating every tick and updates every tick anyway:

public class TileEntityEnderLift extends TileEntity {
public void updateEntity(){
	List mobs = worldObj.getEntitiesWithinAABB(EntityLivingBase.class, AxisAlignedBB.getBoundingBox(xCoord - 0.5, yCoord + 1, zCoord - 0.5, xCoord + 0.5, yCoord + 100, zCoord + 0.5));
	for (int j = 0; j < mobs.size(); ++j){
		EntityLivingBase mob = (EntityLivingBase) mobs.get(j);
		mob.motionY = 0.1;
		mob.fallDistance = 0;
	}
}
} 

This tile entity doesn't have the boolean for updating every tick and updates every tick anyway:

 

He meant he should make a boolean field (may be called isInitialized) that's by default false, and on update, if it is false set to true and initialize...

Yep, a boolean flag and initializing in update works fine. It's just not as clean as I would like it, but it's fine. Thanks again!