Destroy / Remove blocks (10x10x10) when the block is clicked with an item.

[Gepardius]

I have an item which when useOn-ed should remove the block/change it to AIR.

I am using the line below:

level.removeBlock(positionClicked, false);

Once I run the client, the block is briefly removed and then reappears. I've also tried removing the block with:

level.destroyBlock(positionClicked, false);
level.setBlock(positionClicked, Blocks.AIR.defaultBlockState(), 1);

My guess is that I am not registering something correctly/the removed blocks are not applied to the client.

My full code:

public class TeleportationItem extends Item {
    public TeleportationItem(Properties pProperties) {

        super(pProperties);
    }

    @Override
    public InteractionResult useOn(UseOnContext pContext) {

        Level level = pContext.getLevel();
        if (level.isClientSide){
            BlockPos blockpos = pContext.getClickedPos();
            BlockState blockstate = level.getBlockState(blockpos);

            BlockPos positionClicked = pContext.getClickedPos();
            Player player = pContext.getPlayer();

            double x_pos = positionClicked.getX();
            double y_pos = positionClicked.getY();
            double z_pos = positionClicked.getZ();

            double x = positionClicked.getX();
            double y = positionClicked.getY();
            double z = positionClicked.getZ();

            Boolean isLevelClientSide = level.isClientSide();

            for(int i = 0; i < 10; i++){
                 x += 1;
                for(int ii = 0; ii < 10; ii++){
                    y += 1;
                    for(int iii = 0; iii < 10; iii++){
                        BlockPos blockToRemove = new BlockPos(x, y, z);
                        level.removeBlock(blockToRemove, false);
                        z += 1;
                    }
                }
            }

            String text = "clicked block " + " " + x_pos + " " + y_pos + " " + z_pos + " " + blockstate + " " + isLevelClientSide;
            player.sendMessage(new TextComponent(text), player.getUUID());

            return super.useOn(pContext);
        }
        return super.useOn(pContext);
    }
}

Any help would be greatly appreciated.

[Luis_ST]

9 minutes ago, Gepardius said:

if (level.isClientSide){

i think you forgot the !, since removing Blocks is always done on server

Edited July 22, 2022 by Luis_ST

[Gepardius]

Great thank you! It's just taking slowly taking the time to remove blocks and visibly only 1 is removed. Maybe a dumb question, but is there a way to also refresh the server on click, so that the blocks are instantly removed? 

Edited July 22, 2022 by Gepardius

[Luis_ST]

21 minutes ago, Gepardius said:

Great thank you! It's just taking slowly taking the time to remove blocks and visibly only 1 is removed. Maybe a dumb question, but is there a way to also refresh the server on click, so that the blocks are instantly removed? 

you removing 10*10*10 Blocks each click, this are 1000 Blocks i think this is a performance issue,
you can use a BlockPos.MutableBlockPos instead of evertime a new BlockPos

Do you know basic java, usage of the for loop?

Edited July 22, 2022 by Luis_ST

[Gepardius]

I know Python & VBA, have just started with Java, so the syntax is a bit new to me, but atm I am not struggling with syntax, but with what method to call for certain task... 

BlockPos.MutableBlockPos how does it work? 

[Luis_ST]

3 minutes ago, Gepardius said:

BlockPos.MutableBlockPos how does it work?

create before the loops a new BlockPos.MutableBlockPos,
and before you remove the Block you move the BlockPos.MutableBlockPos via BlockPos.MutableBlockPos#move to it's new Position

6 minutes ago, Gepardius said:

I know Python & VBA, have just started with Java, so the syntax is a bit new to me, but atm I am not struggling with syntax, but with what method to call for certain task...

i would recommend you to take a look at the usage of for loops and how to use the "index value" of the for loop

[Gepardius]

Thank you for taking the time to answer. 

I must be doing something wrong, but I will not bother you anymore, since it's my lack of Java knowledge and experience that it's the issue.

At the moment I have:

BlockPos.MutableBlockPos blockMutable = new BlockPos.MutableBlockPos();
BlockPos blockToRemove = new BlockPos(x, y, z);
for(int i = 0; i < 3; i++) {
  for(int ii = 0; ii < 3; ii++){
    for(int iii = 0; iii < 3; iii++){
      level.removeBlock(blockToRemove, true);
      blockMutable.move((int)x, (int)y, (int)z);
      blockToRemove = new BlockPos(x, y, z);
      z += 1;
    }
    y += 1;
  }
  x += 1;
}

Just curious, what would be different/easier with using the "index values"?

[warjort]

To take advantage of the mutable you want code more like:

		BlockPos.MutableBlockPos blockMutable = new BlockPos.MutableBlockPos(x, y, z);
		for(int i = 0; i < 3; i++) {
		  for(int ii = 0; ii < 3; ii++){
		    for(int iii = 0; iii < 3; iii++){
		      level.removeBlock(blockMutable, true);
		      blockMutable.move(Direction.SOUTH);
		    }
		    blockMutable.move(Direction.UP);
		  }
		  blockMutable.move(Direction.EAST);
		}

 

If you look at the BlockPos class there are static methods such as betweenClosed() that let you create iterables or streams for different shapes.

These methods use a MutableBlockPos internally.

[warjort]

I think your problem is your iteration logic is wrong. You need to reset after each inner loop.

Your logic as it stands moves south 3, then up 1 then south 3 again, then up 1, you see the problem?

[Gepardius]

Thank you with the blockMutable help. Yes you are right, I should reset the coordinates, otherwise z and y are always just going up. 

I'm resetting the coordinates now: 

BlockPos blockToRemove = new BlockPos(x, y, z);
for(int i = 0; i < nOfBlocks; i++) {
  for(int ii = 0; ii < nOfBlocks; ii++){
    for(int iii = 0; iii < nOfBlocks; iii++){
      blockToRemove = new BlockPos(x, y, z);
      level.removeBlock(blockToRemove, true);
      // System.out.println(x + " " + y + " " + z);
      z += 1;
    }
    z = z_pos;
    y += 1;
  }
  y = y_pos;
  x += 1;
}

And am applying these changes server and client side, so the blocks are instantly removed now (even 50x50x50).

However, I'm not using mutableBlock, since I don't quite understand how it works just yet. Is the performance better than what I'm using?

[warjort]

https://stackoverflow.com/questions/214714/mutable-vs-immutable-objects

Doing lots of new operators in a short time will create lots of garbage which can stress the garbage collector if you do it too much.

Its the kind of thing you might not see in development with only 1 user, but will be more of a problem as you try to scale up.

[Gepardius]

Okay I understand. At the moment I am fine with only 1 user, since I'm only just learning and I don't plan on scaling it too big. If I do in the future, I will hopefully be a lot more experienced by then and will know what and why I'm doing things. 

Now I'm figuring out how to remove from both sides of the selected block equally. (ex. if middle block is 000, to remove 001, 000 and 00-1 etc.)

[Draco18s]

BlockPos.GetAllInBox, or whatever mojang called it.

It literally gives you an iterable that solves this.

[Gepardius]

Hmmm... I couldn't find the method. I solved it with getDirection() that the player is facing, offsetting x/z and looping. And its working as it should. However, Mojang most definitely has predefined shapes that could be used, since I would love to use a Spiral/and ball shape in the future, but I just can't find it.

[warjort]

The method is the BlockPos.betweenClosed() I mentioned earlier. You give it the opposite corners.

There are few variants for Iteratables and Streams and different ways of passing the parameters.

[Gepardius]

Aha, found it. Do you by any chance have a saved use case?

I understand that you give it the opposite corners, but I don't know how I would get X, Y and Z for each block inside the shape, so that I would pass it into the first below line,

BlockPos blockToRemove = new BlockPos(x, y, z);
level.setBlock(blockToRemove, Blocks.WATER.defaultBlockState(), 1);

instead of looping for each x, y, z as I do now.

[warjort]

Now you are back to asking java questions.

You need to research how Iterable and Stream are used for iteration in java. They are ubiquitous concepts.

Or you can just use your ide to find the many uses in the vanilla code.

[Gepardius]

Okay, I will research it. Thank you for the help and pointers, I really appreciate it. 

[Gepardius]

Another basic question: From which class can the Targeted Block: X, Y, Z (seen in F3 mode) be acquired? 

[warjort]

Entity.pick() for the relevant player.

See: https://github.com/MinecraftForge/MinecraftForge/blob/bb4818630c0c6cdd7c4178b4d77dc406153c2bcb/src/main/java/net/minecraftforge/client/gui/overlay/ForgeGui.java#L680

[Gepardius]

Thank you warjort, works perfectly! Do you know this by heart? Or how did you find it, because I'm struggling with finding decent documentation...

[Gepardius]

For anyone else with the same question. This gets me the block that is in the Player's crosshair. I'm increasing the rayTraceDistance, which is 20.0D by default, so the Player is able to teleport farther. 

Entity entity = Minecraft.getInstance().getCameraEntity();

rayTraceDistance = 500.0D;

HitResult viewedBlock = entity.pick(rayTraceDistance, 0.0F, false);
Double x = viewedBlock.getLocation().x;
Double y = viewedBlock.getLocation().y;
Double z = viewedBlock.getLocation().z;

rayTraceDistance = 20.0D;

Edited July 25, 2022 by Gepardius

[Draco18s]

16 hours ago, Gepardius said:

Minecraft.getInstance()

This is client side only.

[Gepardius]

Does it make a difference, since I'm only using it to get x, y, z? The changes are then applied both to client and server.

[Luis_ST]

43 minutes ago, Gepardius said:

Does it make a difference, since I'm only using it to get x, y, z?

yeah it does, if this code is called on a DedicatedServer it will crash, since the Minecraft class does not exists on the server.
Please show more of your code to understand your usage, ideally the whole class.