[1.9] Allowing player to pick custom entity item up once

[Jedispencer21]

What I am thinking of doing is, for my gun mod that I am creating is making monsters drop a new type of item, like the EntityItem, but they can only pick it up once, then it will stop rendering for them, but other players can still see it/pick it up until the pick it up. What would be the best way of doing this? Would using a list of player names or UUID, or what ever, and saving it to NBT be the better way of doing this?

[Jedispencer21]

I should rephrase it as it is not exactly an item, but more of the entity is like the EntityItem as in it drops when you kill a monster, and when you collide with it, it add a material to the player. Since with my mod, crafting is not done with items per say, but more of I have a capability that stores materials as integers, and when you kill a monster, it should drop this material item. And when I say you can only collect it once, think of it as like drops are different for each player as in every player can pick it up and it will "disappear" for them, but others can still pick it up.

[coolAlias]

So the same drop from a monster can be picked up by multiple players? Is there a limit to the number of players that can benefit from a single monster?

 

What I would do is simply set the drop's stack size to an appropriate number, and then use a custom EntityItem so you can manage the pickup process. There, you check if your player has already accrued this item - if so, do nothing; if not, subtract 1 from the stack size and grant the player that material.

 

If you are concerned about the item still rendering, you could try killing it on the client-side only for the player that picked it up. Might have some unintended consequences, but it could work.

 

However, I think this system would work best if the dropped stack can be picked up only by one player at a time. You still need to override the pickup mechanics using a custom entity (or one of the Forge events), but then you don't need to worry about the rendering bit.

 

If you want to allow more than one player to benefit, simply drop more of the item as separate EntityItem instances, each with a size of 1, and don't let them merge together. You could do a quick count of the number of players within a certain distance of the mob when it is killed and use that to decide how many to drop.

[Jedispencer21]

So, with again, it should be rephrased that this is not an item, its its own entity but it is like the EntityItem in the fact that it drops from entities, and can be picked up. But essentially what your saying I could do is check for players within a certain area when the entity dies, and for all of those player the entity drops a material, and only the player it dropped for can pick it up, and see it? How would I go about doing that part with only technically dropping for one player, and only that player can see it?

[coolAlias]

It doesn't really matter whether it's just an Entity or an EntityItem (which is just a specific type of Entity) - you can do whatever you want within your own class.

 

But anyway, yes, you can do it easily. Make your Entity class ownable and set the owner to the player you want to pick it up. Only allow this player to 'pick up' the entity object. Send the owner information to the client side via IEntityAdditionalSpawnData, and in your custom render class, only render if the current client player is the same as the entity's owner. That's all you need.

[coolAlias]

@gummby8 Technically that could work, but you don't want to let the client dictate anything like that. Using your setup, a player could easily write a hack that sends client->server packets granting themselves as many different materials as they wish.

[Draco18s]

Really what should happen is that the item exists on the server with a "stack size" equal to the number of nearby players.  Each player that comes along gets 1 of the stack (when the remaining is zero, the entity is deleted).

 

Then use a custom renderer for the client-sided object: if the client-player has picked up the item (perform similar logic to the server side or use packets) then simply stop rendering the item.