I have an entity that uses a Random to decide where it should move. It appears as if they are desynced from server to client. How would I go about syncing the client with the server?

1) Use world.isRemote to determine if the entity is client side, if it is, do nothing.

2) If it is not client side, every time it updates, send any changed data to the client using Packet250CustomPayload

3) Add a packet handler on your client side to handle these packets and update the entity on the client end

I figured that would be the problem. The thing is I don't know how to use packets. Everyone I've talked to says there easy, but no one has ever told me how to do it myself and the tutorial on the forums doesn't make sense

Use a datawatcher. I do it all the time.

In most cases, the server is in control of the entity anyway.

Datawatchers are the preferred method to get server data (small) to the client entity.

For example, I might use a randInt() in the server to determine an entities color.

How to tell the client, so that it can render the proper color? Easy.

 

    protected void entityInit()

    {

        super.entityInit();

        this.butterfly_type = this.worldObj.rand.nextInt(10);

        this.dataWatcher.addObject(20, Integer.valueOf(this.butterfly_type));

    }

 

public void onUpdate()

    { 

    super.onUpdate();

    this.motionY *= 0.6000000238418579D; //Gravity adjustment!

 

    if(this.worldObj.isRemote){

 

    this.butterfly_type = this.dataWatcher.getWatchableObjectInt(20);

    }else{  

    this.dataWatcher.updateObject(20, Integer.valueOf(this.butterfly_type));

    }  

    }

 

Alternately, instead of sending and receiving the value a gazillion times unnecessarily in the update(),

you can make a couple functions to set and get the datawatcher object as needed. Or add a little

counter and only update once a second. Whichever way you do it, it works.

 

BUT PLEASE NOTE: datawatchers ONLY GO ONE WAY - from server to client.

 

There are different types too, byte, int, and even float.

 

Make sure you don't use anything under 20, as most of those indexes are used by

vanilla minecraft.

 

 

 

 

 

 

 

Also, the client will automatically follow the server movement.

Its built in. You don't have to do anything.

 

if(!this.worldObj.isRemote){

this.posX += 0.01f;

}else{

//do nothing because this is the client side and it just works

}